Kveik is a dialect word for "yeast" in Norwegian ("gjær" is the common word for "yeast" in Norwegian ), and today specifically refers to non-purified yeast that contains multiple domesticated (not wild) strains of S. cerevisiae and has been reused for generations in traditional Norwegian farmhouse brewing. Originally the word was used as a verb to mean "to start" or to "begin life"  (~1 hour in).
The words "kveiken", "kveika", and "kveikja" are the dialectic definite articles for the word "kveik", which all translate to English as "the kveik" . The term "kveik" does not refer to a style of beer, but only the yeast used in traditional Norwegian farmhouse brewing (Garshol has encouraged brewers brewing non-farmhouse styles with kveik to call them "X Style Beer Brewed with Kveik" or something similar; see Terminology for more information on suggested approaches to naming classic styles fermented with kveik ). The word "kveik" is specifically used in the western part of Norway for family-owned, non-purified yeast, while other words such as "gjester" are used by central Norwegians, "gong" is used by locals in eastern Norway, "family yeast" is used by some Lithuanian brewers, and "hemjäst" is used by locals in Gotland. The term "landrace yeast" has been proposed to refer to kveik as well as other non-kveik farmhouse yeast cultures (for example, Simonaitis) .
Kveik yeast are extremely diverse genetically, presenting characteristics that are not typical in other brewing yeasts . Most farmhouse brewers have started buying their yeast, but some kveik cultures have been passed down from generations and inherited by modern farmhouse brewers in Norway who still use this yeast today and brew with traditional farmhouse methods. Much of the knowledge about kveik and historical farmhouse brewing in Norway has been researched and publicized by Lars Marius Garshol on his blog, Larsblog, and in the book Beer and Brewing Traditions in Norway by Odd Nordland (1969). In recent years kveik cultures have been sent to yeast labs for propagation and distribution to brewers around the world . The use of kveik is one of the many traditional methods still used by a few farmhouse brewers and homebrewers in Norway, along with other historical methods such as infusing the mash or boil with juniper (Juniperus communis ), not filtering, using short fermentations to achieve low carbonation, the use of wood-fired copper or iron kettles, and sometimes not boiling the wort (Raw Ale) . Kveik can also be used effectively to ferment a wide range of non-farmhouse styles, such as New England IPA and English beer styles, as well as cider, mead, and mash/wash for distillation.
Farmhouse yeasts from other countries such as Lithuania and Russia have been found to be both genetically different and express different fermentation profiles than the kveik yeasts of Norway, and are therefore not referred to as "kveik". See the Farmhouse Yeasts in Other Countries page and "Farmhouse yeast: what do we know?" by Lars Marius Garshol.
For a comprehensive list of kveik and other landrace farmhouse yeasts, see the Farmhouse Yeast Registry maintained by Lars Garshol.
"I see this is about to become a myth, so just to clear things up: kveik is not a style of beer. It's farmhouse yeast." ~ Lars Marius Garshol, December 29, 2016 
- 1 Brief History and Description of Kveik
- 2 Yeast Lab Analysis
- 2.1 Species and Phylogeny
- 2.2 Sensory and Fermentation Profile
- 2.3 Lactic Acid Bacteria and Wild Yeast Contaminations
- 3 Kveik Ring/Kveikstokk and Drying
- 4 Commercial Availability
- 5 Specific Kveik Culture Information
- 6 Farmhouse Brewing Resources
- 7 Videos
- 8 See Also
- 9 References
Brief History and Description of Kveik
Kveik was passed down from generation to generation within the family, and also shared among fellow brewers in the region. In this way, kveik evolved differently than the two major beer yeast genetic groups that are used in industrialized brewing. While mostly POF-, a trait that is selected for in many beer yeast strains that prevents the yeast from producing 4-vinylguaiacol phenol, other traits are reflective of how this yeast was used by traditional farmhouse brewers of the region. For example, as far back as 1621 (and probably prior), kveik was often stored dry on wooden logs called "kveikstokker" for up to a year or longer before being re-used in a new batch of beer (the process of re-using yeast from batch to batch is known as "backslopping" in brewing). Kveik was typically inoculated directly into the wort by submerging the kveikstokker into the wort at 30-40°C. The wort was often high gravity of around 1.080 SG, and the beer was served just after 1-2 days of fermentation beginning at this hot inoculation temperature. The kveik was then taken from the fermenter and dried until its next use. If the kveik went sour or died, brewers would borrow kveik from their neighbors, which was another way of preserving kveik through the centuries. Kveik was sometimes also used to ferment bread. It has been proposed by Preiss et al. (2018) that this treatment has produced yeast strains that are genetically distinct phenotypically from other domesticated yeast strains used in industrial brewing in Europe .
Farmers seemed to have different preferences for top or bottom collecting their kveik for storage . Kveik was stored in many ways. It was often stored in bottles with water or in a well. It was also dried on straw rings, on linen, or pieces of wood with holes drilled through them called "yeast logs". Often ashes were used to help dry the kveik quickly, or in the case of yeast logs, were lowered into the fermentation vessel to collect the yeast and then rolled in flour and allowed to dry for a few minutes, then dipped again to repeat the process. The log was then hung to dry. Although dried kveik was said to last for months or maybe longer, fresh kveik was always preferred and often given away to those who needed new kveik (moldy kveik was thrown away) .
At one time kveik was the only available form of yeast in Norway (and, of course, similar methods for reusing yeast were used all over the world prior to Emil Chr. Hansen's introduction of the pure-yeast system in 1883). However, the existence of kveik has mostly disappeared in recent times. Today kveik remains in the districts of Hardanger, Voss, Sogn, Nordfjord, and Sunnmøre, at least. Kveik is only used by homebrewers who still brew in the traditional methods of Norwegian farmhouse brewing, although the recent spreading of kveik throughout the world has led to a resurgence in its usage to make various types of beer, including non-farmhouse style beers .
Thanks to efforts by Lars Marius Garshol and Håken Hveem, and Norwegian farmhouse brewers Svein Rivenes, Sigmund Gjernes, Bjarne Muri, Terje Raftevold, and others, kveik has been made commercially available to brewers around the world. Much of the analysis has been performed by the National Collection of Yeast Cultures (NCYC) and Escarpment Laboratories. See also the Farmhouse Yeast Registry being maintained by Lars Marius Garshol.
- MTF podcast interview with Lars Marius Garshol Part 1 and Part 2.
- MBAA podcast interview with Lars Marius Garshol about the different types of farmhouse yeast, history, and highlights of farmhouse brewing.
- Garshol's hypothesis that some commercial bread yeast could have originated from farmhouse yeast.
- "Kveik" is not a beer style. Its translated meaning is "yeast". For more information, see Lars Marius Garshol's blog post "What Does 'Kveik' Mean?".
- If you do use kveik in a commercial beer, please consider giving the name of the original owner of the kveik on the label. This gives credit to the brewers who have donated their family heritage to the brewers of the world, and it is also helpful for those who want to know exactly which yeast was used in the beer. If you are uncertain about the name of the owner, consult the Farmhouse Yeast Registry .
- Since the word 'kveik" refers only to Norwegian yeasts, and there are farmhouse yeasts in other countries, the term "landrace yeast" has been proposed to refer to all farmhouse-domesticated yeast. See also Landrace Yeast and this MTF thread discussing the usage of the word "landrace" for these farmhouse yeasts.
- Thread in the Kveik Facebook group on why lab isolated strains are still considered "kveik". It is useful to distinguish between purified single-strain kveik, purified multi-strain kveik, and unpurified original culture .
- Threads on what to call beers made with kveik:
- Ralph Buttersworth post on how to classify classic styles fermented with kveik.
- Thread by Dan Pixley on including kveik cultures on beer labels even if the beers are soured with LAB or secondarily fermented with Brettanomyces.
- Subthread on naming lager styles that are fermented with kveik, particularly Pilsner-style beers.
Yeast Lab Analysis
Species and Phylogeny
- MTF feedback on the NTNU analysis.
- Updates to the Escarpment Laboratories (Preiss et al.) analysis on MTF. and their published paper "Traditional Norwegian Kveik Are a Genetically Distinct Group of Domesticated Saccharomyces cerevisiae Brewing Yeasts".
In general, most of the cultures of kveik that have been analyzed contain more than one strain of S. cerevisiae. The exact number of strains that is present in a given kveik culture is difficult to analyze; generally labs with better equipment and more time can identify more strains than others. Some kveik cultures contain multiple strains of closely related strains of S. cerevisiae, while others contain a more diverse group of strains . The kveik cultures with closely related strains defy what a "strain" isolate is; Richard Preiss describes these kveik cultures as being "heterogenous but related communities", meaning that there can be a lot of genetic overlap between subpopulations in a kveik culture and where one strain begins and another ends is not possible to define . S. cerevisiae was the only species in all of the kveik cultures analyzed by Preiss et al. (2018). Of the 9 kveik cultures analyzed by Preiss et al. (2018), only Muri (which has since been found to be commercially available Bavarian Weizen yeast and not a landrace farmhouse yeast at all; see Landrace Yeast), Simonaitis, and Stranda contained only one strain of S. cerevisiae, while all of the others contained more than one strain of S. cerevisiae up to 9 strains in the case of Granvin (see this table from the paper). A Master's Thesis by Nadia Marlen Aasen from Norwegian University of Life Sciences isolated 4-10 strains from 4 different kveik cultures: Ørjasæter, Otterdal, Gausemel and Gamlegrua. As with Preiss (2018), the only species of yeast found was S. cerevisiae. While only yeast was found in Otterdal and Ørjasæter, the Gausemel also had two bacteria species, Acetobacter malorum and Lactobacillus plantarum, and the Gamlegrua also had L. plantarum .
Genetically, kveik yeast strains form their own group of closely related domesticated ale strains that are a subgroup of the "Beer 1" yeasts (Belgian/Germany/UK/US yeast strains) from the Gillons/White Labs (2016) study that sequenced previously known ale strains and found them to make up two genetically related groups called "Beer 1" and "Beer 2" (see Saccharomyces History of Domestication and "A family tree for brewer's yeast" by Lars Marius Garshol). The closest related domesticated strains were 3 German hefeweizen strains; however, this relation is likely just due to both groups being hybrids rather than having any historic relation . None of the kveik strains sequenced by Preiss et al. (2018) contained the STA1 gene for diastatic activity, which is expected since all of the diastatic yeasts belong to the "Beer 2" group .
Although whole genome sequencing of more kveik strains is needed in order to fully flesh out a family tree of kveik , based on the 6 strains that were analyzed, kveik strains seem to be divided into two related genetic groups, with the Simonatis Lithuanian strain and a Norwegian bread yeast falling outside of these two groups completely, which arguably categorizes them to not actually be considered "kveik". The two groups of kveik probably originated from two ancestors that were hybrids between a "Beer 1" yeast and wild yeast. Interestingly, the kveik cultures that have multiple strains have strains from both genetic groups of kveik. For example, Hornindal, Granvin, Laerdal, and Stordal Ebbergarden all contained strains from both genetic groups of kveik. Overall, their genetic diversity is wider than the genetic diversity of other "Beer 1" subgroups . See this updated family diagram of yeast.
Preiss et al. (2018) also measured the fermentation characteristics of individual kveik strains in their study, the first published data in this regard for kveik. At 86°F (30°C) they found that 11 of the 24 pure strains of kveik outperformed the best control strain (WLP002) in fermentation rate. There was still a very wide range of attenuation rates between the kveik strains (60-90%). Of the 6 strains that had their DNA sequenced, all but one of the Granvin strains fermented maltotriose. All of the strains tested were POF- (meaning they did not produce significant 4-vinylguaiacol phenol). One of these Stordal Ebbegarden strains also contained a unique mutation on the FDC1 gene that results in the inability to produce phenols and has not been reported before in science. They also found that kveik strains tend to produce fatty acid esters at levels that are typical for other domesticated yeast strains, such as ethyl caproate (pineapple, tropical; threshold 0.21 ppm), ethyl caprylate (tropical, apple, cognac; threshold 0.9 ppm), and ethyl decanoate (apple; threshold 0.2 ppm). The kveik strains studied did not produce high levels of the isoamyl acetate ester (banana) and generally lower levels of the fusel alcohol isobutanol compared WLP001 and WLP002. Strangely, 5 of the 6 strains that were analyzed could form spores, which is not typical for brewers yeast .
The kveik strains studied by Preiss et al. (2018) displayed unique abilities as far as withstanding stress in their environment. Most of the strains at least doubled their growth at 43°C and grew to their maximum potential at 40°C, while the control strains WLP001, WLP002, and WLP029 showed limited growth at those temperatures. This demonstrates kveik's ability to withstand high-temperature fermentations. All strains tested died at 45°C .
Kveik strains were also demonstrated by Preiss et al. (2018) to have a higher tolerance to alcohol than some of the domesticated strains tested (WLP001, WLP002, and WLP029), as well as unique flocculation characteristics. Most of the kveik strains doubled in growth in media with 14% ABV ethanol, and about half of them doubled in growth in 16% ABV ethanol media. Half of the strains of kveik were highly flocculant, but some other strains were very poor flocculators. It is possible that since kveik is a mixed culture of several strains of yeast that the highly flocculant strains assist the others in flocculation thus diminishing for the other strains to evolve flocculation properties .
- "Where kveik comes from", an analysis of the Preiss et al. study by Lars Marius Garshol.
- MTF thread post by Richard Preiss summarizing the study's findings.
Sensory and Fermentation Profile
The general flavor profile of kveik yeast is ester-driven and non-phenolic, although a wide range of subtle differences can exist between strains. Kveik in its traditional form is usually a blend of closely related strains. The "Stranda" kveik was described as "lemon, nuts, grain, and straw" by Lars Marius Garshol. The "Hornindal kveik" with bacteria was described as "fruity, milky caramel, honey, and mushroom with a very unique aroma" .
Kveik has adapted to being fermented at relatively warm temperatures without producing off-flavors (fusel alcohols, diacetyl, or acetaldehyde), usually in the range of 30-40°C (86-104°F), but also as high as 43°C (109°F). The beer is finished fermenting within a day or two at these warmer temperatures. Årset kveik has been fermented as low as 4°C (39°F), which produced a clean and drinkable beer with a fruity aroma. They have a high alcohol tolerance of around 13-16% ABV . Omega Yeast Labs describes their two isolates (Voss and HotHead) as being non-phenolic, fruity, and complimenting American citrus hops. They also note that the yeast has a very high temperature range (~68-98°F or ~20-37°C), attenuates high, tends to flocculate well, and also tends to ferment faster at the mid to high temperature ranges, while producing similar ester profiles throughout the entire temperature range. Other kveik cultures generally produce subdued aromas below 20°C (68°F); different kveik cultures react differently at different fermentation temperatures . Despite the fast fermentation timeframe that traditional farmhouse brewers employ and the high flocculation that some kveik have, some kveik and some beer styles/brewing conditions may still require or benefit from a more traditional brewing schedule. For example, some kveik may need more time to clean up diacetyl or hydrogen sulfide, to flocculate or settle out completely, or to completely finish attenuation. Keep mind that the farmhouse beers, brewing techniques, and drinking culture differ quite a bit from modern beers, modern brewing techniques, and modern beer packaging/consumption. For example, shelf stability is generally not a concern for farmhouse brewers. Fermenting beer with kveik on the same fast time schedule and in the same ways as the traditional farmhouse beers and without making adjustments such as increased nutrients or increased conditioning time might result in less than stellar beer for modern styles .
Kveik mixed cultures tend to be very flocculant, even though only about 48% of the individual strains are highly flocculant (it is thought that high flocculating strains help the lower flocculating strains to flocculate). Top-harvested kveik form a thick krausen and tends to float on top of liquid even when stored in the fridge, while bottom-harvested kveik tends to form a thin layer of krausen (see the Farmhouse yeast registry to see which kveik cultures are top vs bottom harvested; the listed harvesting method should be continued so as to continue to select for the correct strains). Harvested kveik can be stored in the refrigerator as a slurry, and survive 1-2 years (a starter should be made after about 6 months of cold storage). Attenuation ranges from 60-90% for single strains, but for mixed cultures, the attenuation is usually on the higher side .
Kveik cultures make identifying individual strains within them difficult because the strains are closely related and there is often not a clear distinction between "strains", nor is there a clear definition of what makes a strain truly unique within the total population of strains that are found in a single kveik culture. Richard Preiss describes kveik cultures as being "heterogenous but related communities", meaning that there can be a lot of genetic overlap between subpopulations in a kveik culture. What exactly is meant by "strain" within the context of kveik cultures has not been defined, and so discussing individual strains of kveik is an inadequate way of discussing kveik .
Kveik cultures have a wide range of fruity aromas, which is a result of above-threshold production of fatty acid esters, such as ethyl decanoate and ethyl caprylate . Richard Preiss from Escarpment Laboratories shared his sensory notes after doing trial fermentations with various kveik strains/cultures. Fermentations were at 30°C in standard wort (1.050, 20IBU) with single strains, not the mixed cultures. 2/3 tasters were blind to the beers and order prior to tasting. This is a single data point on sensory information :
- Sykkylven 1 - clean, fruity, malty, rum-like. big, round, malty, slightly hot
- Sykkylven 2 - subtle fruit, malt accented, slightly lagery-sulfury, lightly floral. medium body
- Laerdal 2 (Laerdal 1 - data not available) - Lightly fruity, slight rubber, floral, sweet taste
- Stranda 1 - citrus, red apple, very clean and dry, balanced
- Stordal (framgarden) 1 - big citrus ester, slightly hot, red apple, floral, malty
- Stordal (framgarden) 2 - red apple, slight crisp/sulfury (pleasant) lagery character, floral, slight tropical fruit, slight tartness
- Stordal (ebbegarden) 1 - rum-like, slightly hot, medium mixed esters, round and malty
- Stordal (ebbegarden) 2 - Christmasy, citrus, red apple, floral, clean and balanced flavour
- Muri 1 (not related to kveik genetically; later found to be Bavarian Weizen yeast) - Earthy, herbal, sulfury, apple, pear, very slight clove, not super dry despite ridiculous attenuation (~95%)
- Voss (Gjernes) 1 - Orange, floral, balanced flavour, good body
- Voss (Gjernes) 2 - Cidery, floral, slight earthiness, slight orange, clean, dry
- Hornidal 1 - Tropical, pineapple, rum-like, caramel, citrus, balanced malt/hop
- Hornidal 2 - Floral, rose-like, sulfury, orange, rum-like, very malt accented
- Hornidal 3 - Orange, red apple, rum-like, caramel, balanced
- Granvin 1 - Lower intensity orange, red apple, slight pineapple, textbook “Kveiky”, balanced
- Granvin 2 - Balanced esters, not as intense - citrus, slight (pleasant) sulfur, dry and thin
- Granvin 3 - very muted aroma, clean flavour
- Granvin 4 - floral (rose), honey, slight diacetyl, medium-low esters, complex but not necessarily good
- Granvin 5 - light fruit, light floral, rubber, sweet taste.
- Granvin 6 - fruity, floral, rum-like, citrus, slight diacetyl, balanced flavour
- Granvin 7 - Slight fruity, very thin and astringent
- WLP001 (control) - very fusely/hot, subtle floral note.
Note regarding Granvin strains: Preiss is still trying to sort out which Granvin yeasts are duplicates and which are unique.
Final Beer pH
Kveik also tend to finish beers at a slightly low pH than conventional ale yeast and lager yeast. In a survey of data from around 60 strains of yeast total, Escarpment Labs showed that kveik strains on average finished around 4.25 final beer pH while conventional ale/lager yeast strains finished on average around 4.50 final beer pH for the same wort. This can have an impact on the overall sensory nature of kveik. For example, a lower pH is sometimes associated with the perception of a thinner body as well as a harsher and more astringent hop character. The use of buffering minerals in the mash such as baking soda, lime, or chalk, can help adjust the pH back up if desired .
This tendency to producer slightly lower pH beers than normal brewing yeast is not universal, however. Fermentation conducted with unpurified original kveik cultures may have different results than single isolate strains. For example, Nadia Marlen Aasen's Master's thesis from Norwegian University of Life Sciences found that the same wort (Weyermann Pilsner malt, 60 minute Magnum hops at 18 IBU, and the wort soaked in 1 kg of juniper twigs per 10 liters of wort) fermented with US-05 finished between 3.8-4.0 pH, Ørjasæter kveik finished at 4.1-4.2 pH, Gamlegrua kveik finished at 4.1-4.3, and Gausemel kveik finished at 3.8-4.0 pH .
Pitching rates for kveik are also one of the unique things about these cultures. Kveik cultures are traditionally pitched at a very low rate, perhaps somewhere around the 1-2 million cells/mL for 15-20°P wort. However, pitching at normal ale pitching rates should not produce negative results, and brewers should experiment with the pitching rates for a given kveik strain of mixed culture and determine which pitching rates produce the most desirable results. Escarpment Labs recommends pitching 70% of normal pitching rates, but Richard Preiss reported no issues so far pitching at 25% of normal pitching rates . Omega Yeast Labs recommends normal pitching rates for kveik, but reported no significant difference between under-pitching and normal pitching rates; however, reports of off-flavors might be related to extreme under-pitching and/or lack of nutrients  (~1:03:20 mins in). Oxygen should be at least in the 5-8 ppm range, although 10-12 ppm might be beneficial. Dried kveik cultures have a cell density of around 9-18 billion cells per gram of dried yeast (Fermentis has around 31 billion cells per gram by comparison), and so pitching as little as 10 grams of dried kveik into 100L of wort is fine. Dried kveik is generally rehydrated in first runnings for about 2-4 hours before pitching into the main batch (lautering in traditional farmhouse brewing can take a long time), with a yeast scream being traditional to ward off evil spirits. Kveik cultures are heavily dependent on nutrients, and wort that is lower than 1.050 can benefit from doubling nutrient additions . Richard Preiss recommends 180+ ppm of free amino nitrogen (FAN), along with vitamins (yeast nutrient blends offered by many yeast labs should be able to satisfy these requirements; contact the vendor to find out the specified FAN dosage and vitamin content) .
Escarpment Laboratories presented the first controlled experiment and data set for how pitching rates might affect kveik. The lab fermented their Årset blend (a selection of several strains from Årset; see this explanation from Richard Preiss), Ebbegarden (contains two strains from the original Ebbegarden), the Escarpment Labs Voss single isolate, the Escarpment Labs Raftevold's Hornindal (contains two strains from the original Raftevold Hornindal), and the Vermont ale strain which was used as the control. The strains were fermented at 20ºC (the lab would have preferred to ferment at a warmer temperature, but this was a part of a much larger fermentation experiment with many other brewing strains and they were limited due to limited temperature control equipment). The pitch tested rates were:
- 1 M/mL (1 million cells per mL, 10% of a typical pitch rate)
- 7 M/mL (7 million cells per mL, 70% of a typical pitch rate)
- 10 M/mL (10 million cells per mL, a typical pitch rate)
They monitored specific gravity, FAN consumption, pH change, alcohol/glycerol production, and aroma compound production (using GC-MS). All ferments were performed in triplicate. Their major findings are listed as follows:
- A low pitching rate of 1 million cells/mL attenuated the sample slightly slower than the higher pitching rates, but all pitching rates resulted in a similar finishing gravity, including the Vermon Ale yeast. The kveik fermented faster than other brewer's yeast even at the lower fermentation temperature.
- There were no clear trends as far as how much FAN was consumed by the kveik based on pitching rate, although Årset and Vermont Ale yeast consumed less FAN for the lowest pitching rate. They concluded that high FAN levels are recommended, especially for lower gravity wort.
- Terminal pH was lower for Årset and Ebbegarden, and a little higher for the other strains (~4.15 versus ~4.4); however, pitching rate did not correlate to any patterns.
- No discernible trend in over all ester production depending on pitch rate, although there were some differences depending on ester type and kveik.
- Kveik produce more organic acids than Vermont Ale yeast, duplicating results from the previous Escarpment Labs study on kveik.
- Årset and Ebbegarden produced citronellol at levels similar to Vermont Ale yeast, which indicates that these cultures might be capable of biotransformation similar to the Vermont Ale strain.
- There was a trend for increased aroma intensity for some of the kveiks (Voss and Hornindal) as the pitch rate decreases. However, this is not true for Årset and Ebbegarden, where the trends were less clear.
- MBAA podcast with Richard Preiss and Iz Netto from Escarpment Labs on using kveik.
- Dried kveik viability over time.
- Brulosophy experiment testing pitching rate of Voss Kveik.
Temperature and Growth Rate
While very warm fermentation temperatures have an impact on the speed of potentially attenuation of kveik, temperatures on the higher end of the scale can have a slightly negative impact on the growth rate of some kveik cultures. Aasen's Master's thesis reported that for all three kveik cultures tested (Ørjasæter, Gamlegrua, and Gausemel) the growth rate was slightly higher when incubated at 22°C and/or 30°C compared to being incubated at 37°C. The cultures tended to reach peak cell growth at around day 2 or 3, and then experienced a slight decline until day 7, with this decline after day 2 or 3 being slightly steeper at the hotter incubation temperature of 37°C. The warmer incubation temperature of 37°C did not result in faster growth than the cooler temperatures of 22°C and/or 30°C. Therefore, for optimal growth of kveik for starters or yeast labs, a temperature of 22°C or 30°C might be optimal for some kveik cultures .
Temperature and Attenuation
Higher fermentation temperature seems to not have a large impact on final gravity and attenuation. Aasen's Master's thesis reported statistically insignificant or minimal differences in finishing gravities at different fermentation temperatures for the three kveik cultures tested (Ørjasæter, Gamlegrua, and Gausemel):
|Yeast/Kveik ||Temp (°C)||Original Gravity||Final Gravity|
Microbiologist and blogger Dmitri Kits reported a preference for some strains of kveik for higher fermentation temperatures (35°C or 37°C) versus cooler fermentation temperatures (22°C). Both Lallemand Voss and Omega Hornindal blend fermented faster and achieved a higher attenuation at 35°C or 37°C. The Omega Lutra, however, although fermenting only slightly faster at the higher fermentation temperature versus a lower fermentation temperature of 22°C, finished at a slightly higher gravity at the warmer temperature, indicating that it might have experienced heat stress. Kits hypothesized that based on this data, some strains or kveik are thermophilic, meaning they actually prefer a warmer temperature rather than just being tolerant of it, while Lutra could be thermotolerant (tolerates higher temperatures, but prefers to ferment at a lower temperature) . Kits later reported that the optimal fermentation temperature for Omega Labs Lutra kveik is 33-34ºC, but can still efficiently attenuate wort at temperatures as high as 40-42ºC (although the final gravity was a couple of points higher than at cooler fermentation temperatures). He reported more more acidity and astringent flavors at 40-42ºC and more body and a cleaner tasting beer at 20-28ºC with Lutra .
Comparing fermentation of the three kveik strains to other brewing strains (Mangrove Jack's M15 - Empire Ale, Lallemand Nottingham, Fermentis w-34/70, Lallemand Munich Classic, Mangrove Jack's M44 - West Coast, Mangrove Jack's M31 Belgian Tripel, Fermentis K97 German Ale, and Mangrove Jack's M36 Liberty Bell), Kits reported that at 18-22ºC, the three kveik cultures performed about the same as other ale yeasts, with M15 Empire Ale from Mangrove Jack's and some other ale strains completing fermentation faster than the kveik strains tested. Comparing all of the trials, Lallemand Voss was the fastest fermenting yeast when fermented at 37°C (but much slower at 22°C), followed by M15 Empire Ale from Mangrove Jack's at 22°C, and the third fastest fermentation was Omega Hornindal blend at 35°C .
Kits reported that the optimal fermentation temperature for Escarpment Labs Laerdal kveik is 30°C, which is also the temperature that Dagfinn Wendelbo (the original owner) traditionally pitches this yeast at .
Temperature and Aromatic and Sensory Compounds
Just as with other strains of Saccharomyces cerevisiae used in fermentation, the fermentation temperature can have a significant effect on the different aromatic and flavor compounds produced by kveik Aasen's Master's thesis looked at fermenting three different full culture kveiks, Gamlegrua, Gausemel and Ørjasæter, and US-05 as a control. She tested three different fermentation temperatures, 22°C, 30°C, and 37°C. In general, after 7 days of incubation time, all of the yeasts had higher levels of the esters ethyl acetate, isoamyl acetate,and ethyl hexanoate at the 22°C or 30°C, and nearly half the amounts of esters at 37°C. These were esters were also measured at day 2, and at that time they were much higher in the 37°C fermentation, suggesting that prolonged exposure to the warmer temperature may have dissipated these esters. Ethyl octanoate tended to have slightly higher amounts at 22°C or 30°C, but the differences between the different fermentation temperatures were smaller, and in the case of the Gausemel kveik there was no significant different at all for this ester .
It has been anecdotally reported by brewers that high levels of off-flavors from higher alcohols are not produced at fermentation temperatures up to 35-40°C with kveik. In general, Aasen's Master's thesis reflected these anecdotal reports. The amount of the higher alcohol 2-methyl-1-propanol was nearly double at 30°C and 37°C versus 22°C for the control yeast strain, US-05. For the three kveik cultures that were tested, Gamlegrua, Gausemel, and Ørjasæter, the amount of this higher alcohol was only slightly elevated at the higher fermentation temperatures, but still remained under the lowest levels that US-05 produced when fermented at 22°C. The higher alcohol 1-propanol had a similar trend. At 30°C and 37°C, US-05 produced significantly more of this higher alcohol, while the three kveik cultures produced only slightly elevated or the same levels regardless of fermentation temperature. The levels of 1-propanol that were produced by the three kveik cultures at all three fermentation temperatures were, in general, around the same amount that US-05 produced at 22°C. Two other higher alcohols that were measured, 2-methyl-1-butanol and 3-methyl-1-butanol, were roughly the same for all three fermentation temperatures for all three of the kveik cultures and US-05, with 2-methyl-1-butanol tending to be slightly higher in the warmer fermentation temperatures for all of the kveik cultures and US-05. One of the higher alcohols tested, 2-hexanol, had nearly double or triple the levels when fermented at the cooler temperature of 22°C versus 30°C and 37°C, indicating that this particular higher alcohol follows an opposite trend than most higher alcohols produced by yeast. The levels were the same for all three of the kveik cultures and US-05 .
For the kveik cultures Gamlegrua and Gausemel, Aasen reported elevated levels of acetaldehyde were found at the warmer fermentation temperatures of 37°C, but not for Ørjasæter or US-05. The aldehyde 2-methyl-propanal was elevated at 37°C for all four of the cultures tested (Gamlegrua, Gausemel, Ørjasæter , and US-05). The aldehydes 2-methyl-butanal and 3-methyl-butanal, and the ketone diacetyl, were not significant for any of the cultures tested nor at any of the different fermentation temperatures (22°C, 30°C, 37°C) .
Other Sensory Data
- Google Spreadsheet of anecdotal experiences the fermentation characteristics and flavor of different kveik cultures (translate from Norwegian).
- Roi Krispin's project to have 16 homebrewers judge and compile flavor descriptors for beers brewed with a simple recipe and split fermentation with Sigmund Gjernes Voss, Terje Raftevold Hornindal, Tormodgarden, Ebbegarden, Framgarden, and Simonaitis.
- Travis Morita's experiment with a simple wort and sensory testing using DraughtLab and 7 blind tasters; kveik tested: Voss (Imperial Loki), Hornindal (Omega), Oslo (Bootleg Biology), Ebbegarden (original culture), Framgarden (original culture), and Opshaug (White Labs).
- Brülosophy blind triangle test of a Helles Exportbier style wort fermented with Bootleg Biology's OSLO at either 64°F/18°C or 98°F/37°C.
Various Interesting MTF Threads
- MTF thread with tips and experiences with various low pitching rates with different kveik cultures.Archive
- MTF thread on dry hopping at warmer temperatures when fermenting with kveik.
- MTF thread on getting nail polish from some kveik cultures and where that might come from.
- Richard Preiss recommendations on avoiding sulfur in kveik fermentations.
- MTF thread by Zach Taggart on kveik producing esters similar to levels produced by kolsch yeast, and checking the accuracy of hyping kveik flavor profiles.
- Brewing Pilsner-like styles with good clarity.
- NEIPA with Voss Kveik, including an attenuation graph.
- Kveik and ester production.
- Finding traditional farmhouse ale made commercially, and commercial beers that conflate tradition.
- Fermenting at colder temperatures, including lager temperatures.
- Discussion on blending different kveik isolates or original kveik cultures.
Lactic Acid Bacteria and Wild Yeast Contaminations
Some of the kveik cultures that are not isolated cultures have reportedly been contaminated with lactic acid bacteria. These contaminations probably occurred during handling of the yeast at some point. See Justin Amaral's statements regarding this issue. The lactic acid bacteria found in contaminated kveik cultures can be inhibited by ~10 IBU . Traditionally, if contaminating microorganisms start having an impact on the flavor of the beer, the brewer would throw away their kveik and borrow a fresh culture from a neighbor .
Juniper Antimicrobial Effect
Juniper twigs partially inhibit Lactobacillus growth. Juniper needles, ripe berries, and unripe berries have little to no significant impact. Juniper is often used in farmhouse brewing. Sometimes it is used as a mash filter, and sometimes it is used to make a juniper infusion called "einerlog" which is sometimes used for the mash water . See Lactobacillus "Other Plant Type Tolerance" for more information.
Kveik Ring/Kveikstokk and Drying
As Norwegian farmhouse brewers only brew 2-3 times per year, kveik has adapted to being dried and stored for long periods of time in-between usage, which is unique among most domesticated yeast . Storing the kveik in a dried form allows the yeast to survive longer than if it is kept as a wet slurry, and might help prevent contaminants from surviving. Kveik was often dried on parchment paper and kept in bags in the freezer. Wooden carvings known as a "kveik ring" or a "kveikstokk" were also sometimes used to store dried kveik, although this might be an older practice compared to drying kveik on parchment paper. Using a kveik ring or kveikstokk is simple: drag the kveik ring (more broadly known as a "twisted torus" , or more specifically called a "gjærkrans" or "yeast wreath" in Norwegian when used for yeast ) or kveikstokk through the krausen of a fermenting beer, and then hang the ring/kveikstokk to dry. On the next batch, the ring/kveikstokk is dunked into wort to reactivate the yeast . Note that not all yeast reacts well to drying. Kveik has this exceptional ability. For example, Brettanomyces is known to not be tolerant of drying/desiccation .
- MTF thread with images of using a kveikstokk.
- MTF thread on drying kveik on parchment paper. See also this post by Matt Spaanem on drying yeast (including some wild yeast strains) on parchment paper.
- MTF thread on successfully drying Omega Yeast Lab's Hornindal kveik using a dehydrator.
- Bryan Heit's drying instructions using a jerky dehydrator and viability testing of dried kveik over a few months (see previous parts as well).
- Rodrigo Borges de Azevedo's method of drying with 100% cotton or cotton blended with linen or polyester.
- "Brewing with kveik" by Lars Garshol, with an example of using a yeast ring.
- Matt Spaanem's blog post on using a smaller kveikstokk for a wild caught yeast culture.
- Antonio Golia's write up on making and using a kveikstokk (in Italian; use an online translator).
Using Dried Kveik and Viability Over Time
Dried kveik should be stored in the freezer, and has been known to be recoverable after 20 years when stored in this way. While recovery of very old dried kveik may be possible using microbiological techniques, very old dried kveik might not be viable enough for brewers to revive using simple starter techniques. Microbiologist Dr. Bryan Heit measured the viability of kveik that was dried using a dehydrator and stored in a home freezer and found that viability decreased by about 6-8% per month. Dr. Heit estimated (and then later confirmed via cell counts) that at 6 months, the kveik would be at about 50% viability, which is good enough to pitch directly into wort without a starter. Therefore, if the kveik has been frozen for 6 months or less, dried kveik can be thawed and simply added to a liter or so of ~30°C (86°F) wort for 2-4 hours before adding that to the main batch of wort. If the dried kveik is older than 6 months, a starter is recommended. Dr. Heit used Voss kveik for his experiment, and included some limitations such as sample size, using kveik from a yeast cake instead of using fresher yeast from top cropping or a starter, using a yeast cake with a high hop content (while hops are not toxic to yeast, a high content of hops could further stress the yeast), using a dehydrator that had high and fluctuating temperatures instead of a better quality dehydrator (Dr. Heit recommends drying at 35-40°C), and probable under-estimates of viability due to using trypan blue dye, which is known to stain both dead cells and cells that are alive but are undergoing cell division .
History and Crafting How To's
- "Scandinavian Yeast Rings - the curious case of the Twisted Torus," by Susan Verberg, 2019.
- MTF thread on building a kveik ring.
- Poppyland Brewer instructions on how to build a kveik ring.
- Instructions on building a kveik ring and history information by George Hart.
- "Kveik: Norwegian farmhouse yeast" by Lars Garshol, with images of ancient kveikstokk.
- MTF thread on an old kveik ring from Vågå that was sent to hopefully revive the old dried kveik on the ring.
- Step by step video instructions by Jeff Pryor:
Kveik Rings for Sale
- Tim Oelke of Suds n' Sawdust offers kveik rings in the US for sale.
- Craft Labs in Sweden offers kveik rings off and on; contact info at craftlabs dot se.
This is a summary of commercially available kveik cultures. See the above descriptions, the Farmhouse Yeast Registry, and the vendor's website for more information about the cultures. Most are single strain isolates, while some contain multiple strains or the native "unpurified" mixed cultures (this is of interest to some brewers, especially Norwegian brewers, because single isolates potentially perform differently than original cultures with multiple strains and as such will be denoted in the Notes column). Note that strain information can be misleading because the nature of kveik cultures make talking about individual strains difficult due to the strains being closely related yet diverse. Richard Preiss describes kveik cultures as being "heterogenous but related communities", meaning that there can be a lot of genetic overlap between subpopulations in a kveik culture and where one strain begins and another ends has yet to be defined (see Recent Lab Analysis above) . Additionally, it is legal and quite common for yeast labs to culture strains from another yeast lab and brand them as their own, thus many single isolates are likely to be duplicates of whichever lab initially isolated them (this is unverifiable unless the yeast lab in question shares how they obtained their isolate or independent DNA sequencing is done; we include such information when it is available to us). Commercially available non-kveik landrace farmhouse yeast are listed on the Landrace Yeast page.
|Kveik||Registry Num||Yeast Lab||Package||Notes|
|Sigmund Gjernes's Voss||1||Omega Yeast Labs||Voss Kveik OYL-061||Single strain isolate. Omega Yeast Labs and The Yeast Bay independently isolated one of the strains from the Voss Kveik. It is not known if these are the same strains, or which NCYC strain they correspond to. However, they are thought to be similar in their flavor profile .|
|Sigmund Gjernes's Voss||1||The Yeast Bay||Sigmund's Voss Kveik (WLP4045 from White Labs)||Single strain isolate. Potentially the same as the Omega Yeast Labs Voss strain; see the Sigmund Gjernes's Voss entry for Omega Yeast Labs Voss Kveik OYL-061 above .|
|Sigmund Gjernes's Voss||1||Mainiacal Yeast||The full, unpurified (no microbes isolated or removed) culture. Limited availability.|
|Sigmund Gjernes's Voss||1||Escarpment Laboratories||Voss Kveik||Single strain isolate.|
|Sigmund Gjernes's Voss||1||Sleight Beer Lab||Gebo Nordic Yeast Pitch||Single strain isolate; sold dried.|
|Sigmund Gjernes's Voss||1||Imperial Yeast||Loki||A single strain isolate; likely to be the same isolate as the Omega Voss Kveik OYL-061 isolate .|
|Sigmund Gjernes's Voss||1||East Coast Yeast||ECY43 Nordic Farmhouse||Single strain isolate.|
|Sigmund Gjernes's Voss||1||Fermentum Mobile (Poland)||FM53 Voss kveik||Single strain isolate.|
|Sigmund Gjernes's Voss ||1||Inland Island Yeast Laboratories||INIS-441 Norwegian Farmhouse||Single strain isolate|
|Sigmund Gjernes's Voss||1||Community Cultures Yeast Lab||The Fruity Norwegian (formerly called "Kveik", and "The Fruity Norwegian" was formerly the brand name for a different unknown kveik culture that the company removed from market )||Single strain isolate|
|Sigmund Gjernes's Voss||1||Propagate Lab||MIP-340 Voss Kveik Isolate||Single strain isolate.|
|Sigmund Gjernes's Voss||1||Yeastlab (Brazil)||YLB1010 - Kveik 01||Single strain isolate .|
|Sigmund Gjernes's Voss||1||Lallemand Brewing||Voss Kveik Ale Yeast||Single strain isolate . See this MTF comment from a Lallemand representative regarding cell counts in this product. See "Voss kveik optimum fermentation temperature," for a data point on attenuation rate at different temperatures with this strain (note that this data may not be reproducable with other strains isolated from Sigmund Gjernes kveik by other yeast labs).|
|Sigmund Gjernes's Voss||1||Kveikshop||#1 Sigmund Gjernes||The full, unpurified (no microbes isolated or removed) culture. Dried format; ships international.|
|Sigmund Gjernes's Voss||1||Jasper Yeast||JY247 - Voss Kveik||Single isolate. |
|Rivenes||2||Escarpment Laboratories||Rivenes Kveik||Potentially a one-time release under the lab's monthly "Kveik Ring" kveik release .|
|Rivenes||2||Mainiacal Yeast||Dried Kveik - Rivenes||Dried format. Rivenes has the classic orange character that many Kveik has. It does have one Lactobacillus strain in the mix, but is intolerant of 10 IBU. This Lactobacillus complements the orange notes .|
|Stein Langlo's Stranda||3||Omega Yeast Labs||HotHead Ale OYL-057||Single strain isolate (only one strain was revived by NCYC).|
|Stein Langlo's Stranda||3||Mainiacal Yeast||Dried Kveik - Stranda||The full, unpurified (no microbes isolated or removed) culture. Limited availability.|
|Stein Langlo's Stranda||3||Propagate Lab||Stranda Single Isolate||Single strain isolate (only one strain was revived by NCYC).|
|Stein Langlo's Stranda||3||Kveikshop||#3 Stranda, Langlo||The full, unpurified (no microbes isolated or removed) culture. Dried format; ships international.|
|Terje Raftevold's Hornindal||5||Escarpment Laboratories||Hornindal Kveik Blend||Two strains isolated from the original culture.|
|Terje Raftevold's Hornindal||5||Escarpment Laboratories||July 2020: Hornindal Farm Kveik||The full, unpurified (no microbes isolated or removed) culture; contains lactic acid bacteria. Potentially a one-time release under the lab's monthly "Kveik Ring" kveik release |
|Terje Raftevold's Hornindal||5||Mainiacal Yeast||The full, unpurified (no microbes isolated or removed) culture; contains lactic acid bacteria. Limited availability.|
|Terje Raftevold's Hornindal||5||Omega Yeast Labs||Hornindal Kveik||Original culture, but "purified" to remove the lactic acid bacteria.|
|Terje Raftevold's Hornindal||5||Omega Yeast Labs||OYL-071 Lutra™ Kveik||Single isolate from the original Hornindal kveik; characterized as being a "shockingly clean" strain .|
|Terje Raftevold's Hornindal||5||Propagate Lab||MIP-342 Kveik Hornindal||The full, unpurified (no microbes isolated or removed) culture.|
|Terje Raftevold's Hornindal ||5||Bio4 (Brazil)||SY081 Norwegian Kveik||Single strain isolate .|
|Terje Raftevold's Hornindal||5||The Yeast Bay||Hornindal Kveik||Single isolate; characterized as "stone fruit and tropical esters".|
|Terje Raftevold's Hornindal||5||Imperial Yeast||A46 Bartleby||Single isolate; characterized as "pineapple, apricot and peach aromas".|
|Terje Raftevold's Hornindal||5||Kveikshop||#5 Hornindal, Raftevold||The full, unpurified (no microbes isolated or removed) culture. Dried format; ships international.|
|Terje Raftevold's Hornindal||5||Jasper Yeast||JY246 - Hornindal||Single isolate; characterized as "tropical ester flavor". |
|Lærdal||6||Mainiacal Yeast||Dried Kveik - Laerdal||The full, unpurified (no microbes isolated or removed) culture; contains lactic acid bacteria. Sold dried. Limited availability.|
|Lærdal||6||Escarpment Laboratories||Lærdal Kveik||Single strain isolate. Potentially a one-time release under the lab's monthly "Kveik Ring" kveik release .|
|Hans Haugse's Granvin||7||Mainiacal Yeast||The full, unpurified (no microbes isolated or removed) culture. Limited availability.|
|Sigurd Johan Saure's Tormodgarden||8||kveiktraining.com||Dried kveik #8 Tormodgarden / Saure||Sold by the farmhouse directly by Saure. 1 plastic bag containing approximately 15 grams of dried kveik #8 ("#8" refers to the Farmhouse Yeast Registry number). There might be some residue of the brown paper used for drying, but Saure says that it will not affect the fermentation, its all been sanitized before drying the kveik .|
|Sigurd Johan Saure's Tormodgarden||8||Escarpment Laboratories||Tormodgarden Kveik||Potentially a one-time release under the lab's monthly "Kveik Ring" kveik release .|
|Sigurd Johan Saure's Tormodgarden||8||Kveikshop||#8 Tormodgarden, Saure||The full, unpurified (no microbes isolated or removed) culture. Dried format; ships international.|
|Ebbegarden, Stordal||9||Sleight Beer Lab||Ehwaz Nordic||Single strain isolate; sold dried.|
|Ebbegarden, Stordal||9||Escarpment Laboratories||Ebbegarden Kveik Blend||Two strains isolated from Ebbegarden .|
|Ebbegarden, Stordal||9||Mainiacal Yeast||Dried Kveik - Ebbegarden||The full, unpurified (no microbes isolated or removed) culture. Limited availability.|
|Ebbegarden, Stordal||9||Propagate Lab||MIP-343 Kveik Ebbegarden|
|Ebbegarden, Stordal||9||Kveikshop||#9 Ebbegarden, Øvrebust||The full, unpurified (no microbes isolated or removed) culture. Dried format; ships international.|
|Framgarden, Stordal||10||Mainiacal Yeast||The full, unpurified (no microbes isolated or removed) culture. Limited availability.|
|Framgarden, Stordal||10||Sleight Beer Lab||Fehu Nordic||Single strain isolate.|
|Framgarden, Stordal||10||Propagate Lab||MIP-344 Kveik Framgarden|
|Framgarden, Stordal||10||The Yeast Bay||Framgarden Kveik||Single isolate; described as "melon and cantaloupe esters".|
|Framgarden, Stordal||10||Escarpment Laboratories||Framgarden Kveik||Blend of multiple isolates from the original Framgarden . Potentially a one-time release under the lab's monthly "Kveik Ring" kveik release .|
|Framgarden, Stordal||10||Imperial Yeast||A36 POG||Single isolate; described as "tropical fruit aromas".|
|Framgarden, Stordal||10||Kveikshop||#10 Framgarden, Øvrebust||The full, unpurified (no microbes isolated or removed) culture. Dried format; ships international.|
|Lida||11||Mainiacal Yeast||Dried Kveik - Lida||The full, unpurified (no microbes isolated or removed) culture with a strain of Lactobacillus. Limited availability.|
|Lida||11||The Yeast Bay||Lida Kveik||Single isolate; characterized as "apricot, stone fruit, and white grape esters".|
|Lida||11||Propagate Lab||MIP-355 Kveik Lida|
|Årset||13||Mainiacal Yeast||Dried Kveik - Årset||The full, unpurified (no microbes isolated or removed) culture. Limited availability.|
|Årset||13||Escarpment Laboratories||Årset Kveik Blend||Contains multiple inter-related strains; see this explanation from Richard Preiss. Sold as sourced by Jakob Årset, on the farm Årset in Eidsdal, Norway. The overall flavour profile is similar to the Hornindal Kveik Blend, but this blend exhibits a broad temperature range (we have heard of sub-15ºC) and tolerates acidic wort quite well.|
|Årset||13||Jasper Yeast||JY224 - Arset Kveik Blend||A blend of of strains from the original Årset. Characterized as, "low ester and fast fermenting, light notes of pear and apple in low hopped beers." |
|Årset||13||Jasper Yeast||JY252 Arset Kveik Single||Single isolate; characterized as "pear ester flavor". |
|Nornes||15||Mainiacal Yeast||Dried Kveik - Nornes||The full, unpurified (no microbes isolated or removed) culture. Limited availability.|
|Nornes||15||Propagate Lab||MIP-345 Kveik Nornes|
|Midtbust, Stordal||17||Mainiacal Yeast||Dried Kveik - Midtbust||The full, unpurified (no microbes isolated or removed) culture. Limited availability.|
|Midtbust, Stordal||17||The Yeast Bay||Midtbust Kveik||Single isolate; characterized as "restrained ester profile".|
|Midtbust, Stordal||17||Propagate Lab||MIP-347 Kveik Midtbust|
|Midtbust, Stordal||17||Kveikshop||#17 Midtbust||The full, unpurified (no microbes isolated or removed) culture. Dried format; ships international.|
|Midtbust, Stordal||17||Escarpment Laboratories||Nov 2020: Midtbust Kveik||A blend of 5 isolated strains from the original. Potentially a one-time release under the lab's monthly "Kveik Ring" kveik release |
|Nystein||19||Mainiacal Yeast||Dried Kveik - Nystein||The full, unpurified (no microbes isolated or removed) culture. Limited availability.|
|Espe||20||Mainiacal Yeast||Dried Kveik - Espe||The full, unpurified (no microbes isolated or removed) culture. Contains Lactobacillus reportedly tolerant of up to 9 IBU. Described as spice rum/cognac character along with apricot and peach notes. Recommended fermented on the cooler side between 60-85°F. Limited availability.|
|Espe||20||Omega Yeast Labs||OYL-090 Espe Kveik||Single strain isolate.|
|Epse||20||Kveikshop||#20 Epse||The full, unpurified (no microbes isolated or removed) culture. Dried format; ships international.|
|Tomasgard||21||Mainiacal Yeast||Dried Kveik - Tomasgard||The full, unpurified (no microbes isolated or removed) culture, including a hop tolerant Lactobacillus. Limited availability.|
|Stalljen||22||LevTeck (Brazil)||Seljeset Kveik||The full, unpurified (no microbes isolated or removed) culture .|
|Stalljen||22||Escarpment Laboratories||Seljeset Kveik||Four isolates from the original culture. Reportedly one of the fastest fermenting kviek. Potentially a one-time release under the lab's monthly "Kveik Ring" kveik release .|
|Stalljen||22||Propagate Lab||MIP-348 Kveik Stalljen|
|Otterdal||23||Kveikshop||#23 Otterdal, Grodås||The full, unpurified (no microbes isolated or removed) culture. Dried format; ships international.|
|Halvorsgard||28||Escarpment Laboratories||Halvorsgard||Two isolates from the original kveik. Contains POF+ trains, strong fruity aromas with a light "baking spice". Potentially a one-time release under the lab's monthly "Kveik Ring" kveik release .|
|Ner-Saure||31||Mainiacal Yeast||Dried Kveik - Ner-Saure||Dried format. Characterized as having a burnt citrus character and fresh baked bread notes. This culture also has a Lactobacillus in that that is a bit more tolerant around 12 IBU .|
|Wollsæter||35||Mainiacal Yeast||The full, unpurified (no microbes isolated or removed) culture. Limited availability.|
|Wollsæter||35||Kveikshop||#35 Wollsaeter||The full, unpurified (no microbes isolated or removed) culture. Dried format; ships international.|
|Aurland||38||Propagate Lab||MIP-341 Kveik Auland||The full, unpurified (no microbes isolated or removed) culture. May contain bacteria.|
|Aurland||38||Mainiacal Yeast||Dried Farmhouse - Auland||The full, unpurified (no microbes isolated or removed) culture. Potentially POF+, and contains a species of Candida.|
|Skare||41||Mainiacal Yeast||Dried Kveik - Skare||The full, unpurified (no microbes isolated or removed) culture. Limited availability.|
|Skare||41||Escarpment Laboratories||Skare kveik||Pronounced "scar-uh". Blend of 3 isolated strains from skare kveik. Potentially a one-time release under the lab's monthly "Kveik Ring" kveik release |
|Skare||41||Kveikshop||#41 Skare||The full, unpurified (no microbes isolated or removed) culture. Dried format; ships international.|
|Opshaug||43||Mainiacal Yeast||Dried Kveik - Opshaug||The full, unpurified (no microbes isolated or removed) culture. Limited availability.|
|Opshaug||43||White Labs||WLP518||Single strain isolate .|
|Opshaug||43||Propagate Lab||MIP-352 Osphaug|
|Opshaug||43||Kveikshop||#43 Opshaug||The full, unpurified (no microbes isolated or removed) culture. Dried format; ships international.|
|Jordal||44||Escarpment Laboratories||Jordal Kveik||Blend of 4 isolates from the original Jordal. Potentially a one-time release under the lab's monthly "Kveik Ring" kveik release .|
|Jordal||44||Mainiacal Yeast||Farmhouse - Jordal||The full, unpurified (no microbes isolated or removed) culture. Limited availability. It contains a mix of 3 Saccharomyces cerevisiae strains and 2 hop intolerant (tolerates 9-10 IBU) Lactobacillus strains.|
|Hovden||48||Mainiacal Yeast||Dried Kveik - Hovden||The full, unpurified (no microbes isolated or removed) culture. Limited availability.|
|Ebbegarden, Framgarden, Lida, Raftevold gård, and Wollsæter (blend)||Mainiacal Yeast||Kveik the World Blend||Kveik blend dedicated to the late William Holden who created the Kornolfetsival to showcase kveik and helped trade kveik with brewrs outside of Norway. Each selected kveik was collected by William Holden. A portion of the proceeds from each sale will go to William's family. Contains hop intolerant strains of Lactobacillus (5-10 IBU will inhibit sour flavor).|
|Hornindal, Voss, Ebbegarden, and Årset (blend)||Escarpment Laboratories||Kveik The World Blend||Different than the Mainiacal culture of the same name. This was a promotional blend that was handed out for free at HomebrewCon 2019, but the company might hand it out again at future events .|
|Unknown||Bootleg Biology||OSLO|| Single strain isolate. Isolated from Eld & Tid's house culture which is a mix of three kveik cultures from Hornindal (thus the exact original kveik that this isolate comes from is not known) . See this MTF thread on speculating which kveik this isolate could be from. It has been confirmed via ITS sequencing that this strain is within the kveik family but not which kveik culture it comes from .
|Unknown||Bootleg Biology||AURORA||Single strain isolate. Isolated from one of the kveik cultures from Hornindal (the specific kveik culture from Hornindal, of which there are a few, is unknown to Bootleg Biology) .|
|Unknown||Imperial Yeast||A44 Kveiking||A blend of three isolated strains. The origin of the three strains is proprietary .|
|Unknown (blend)||Mainiacal Yeast||Dried Kveik Blend - Juggernaut||A blend of 6 different Saccharomyces cerevisiae strains isolated from 6 different kveik. Limited availability.|
|Unknown (blend)||Mainiacal Yeast||Dried Kveik Blend - Berserker||A blend of 3 different Saccharomyces cerevisiae strains isolated from 3 different kveik. Limited availability.|
|Unknown||Propagate Lab||MIP-354 Oslo||Most likely the same as the Bootleg Biology OSLO.|
|Unknown||WHC Lab (Ireland)||Ubbe||Clean "lager-like" taste and aroma. Single strain isolated from the Hornindal region in Norway . This is reported to be the same strain as Bootleg Biology's OSLO product .|
|Unknown||WHC Lab (Ireland)||Bjorn||Single strain isolate from the Hornindal region in Norway. Characterized as fruity .|
|Unknown||WHC Lab (Ireland)||Lagertha||Single strain isolate from the Stranda region in Norway . Editor's note: this is likely the same strain as Omega HotHead.|
|Unknown||WHC Lab (Ireland)||Odin||Lightly fruity; ferments in the lower 20's °C . Most likely a single strain isolate.|
|Unknown||WHC Lab (Ireland)||Ragnar||Single strain isolate from the Voss region in Norway . Editor's note: this is likely the same strain as Omega Voss.|
|Unknown||WHC Lab (Ireland)||Valkryie||A yeast strain isolated from a kviek isolate from Ebbegarden region in Norway (most likely #9 on the registry .|
|Unknown||White Labs||WLP631||A blend of several unnamed strains of kveik and an unnamed Lactobacillus species.|
Landrace Yeast In Other Countries
There are farmhouse yeasts in other countries and Norway that have survived for generations, similar to kveik, but are genetically distinct from kveik. Since the term "kveik" refers to just Norwegian farmhouse yeast, the term "landrace yeast" has been proposed to refer to farmhouse yeasts as a category of yeast. Non-kveik landrace yeast includes yeasts from Lithuania and Russia such as Simonaitis, Rima, and Jovaru Alus, as well as the Norwegian farmhouse yeast Muri which is not genetically related to any kveik strains.
See Landrace Yeast for more information and commercially available cultures.
Specific Kveik Culture Information
See the Farmhouse Yeast Registry maintained by Lars Garshol for more complete and updated information on individual kveik cultures.
Sigmund Gjernes's Voss Kveik
The NCYC found that a sample of Sigmund Gjernes's kveik was made up of three strains of S. cerevisiae. No bacterial contamination was found. DNA fingerprinting found the strains to be closely related . See Larsblog Kveik analysis report for more information.
- NCYC 3995 - original sample of kveik containing three strains of S. cerevisiae.
- NCYC 3996 - 1st isolate in the 3995 blend.
- NCYC 3997 - 2nd isolate in the 3995 blend.
- NCYC 3998 - 3rd isolate in the 3995 blend.
Tips For Use
- Tips from Andrew Rathband and Lars Garshol on MTF.
- Community spreadsheet tracking fermentation characteristics of many kveik cultures.
- Ryan Brews Blog; Norwegian Table Beer review using The Yeast Bay's Voss Kveik.
- See also the Saccharomyces page for vendor tips.
- Richard Preiss recommends that Voss Kveik can go as high as 13% ABV, but also needs high nitrogen nutrients (especially for a wine fermentation) .
- Experiences with high ABV/braggots.
- Tips for using kveik in hoppy beers.
- Practical Guide to Kveik and Other Farmhouse Yeast by author Mika Laitinen:
This kveik comes from Jens Aage Øvrebust, and was collected by William Holden. Jens originally brewed raw ale, but started boiling the wort because his beer became sour now and then. Pitch at 28C, harvest yeast from the top after a couple of days. Prefers not to let the yeast go over 30. Usually ferments 4-6 days. Sent to NCYC and NTNU, but no results yet. Jens usually ferments down to an SG of 1010, because he doesn't want the beer sweet. He says the yeast has always been in the valley as far as he knows.
Appears to have an unusual relationship with hops, so beware that this yeast may accentuate the hop bitterness in your beers. Jens says he only dry-hops himself. Richard Preiss from Escarpment Laboratories reported that sensory data on how bitter beer tastes with Ebbegarden kveik versus other yeast strains (Hornindal kveik and Conan strain) is that it produces a slightly more bitter beer, but the effect is not big .
Farmhouse Brewing Resources
MTF "The Podcast"
- "Kveik" - what does it mean?
- How To Use Kveik.
- Farmhouse Yeast Registry.
- A family tree of kveik - Summary of Richard Preiss and Carolina Tyrawa's genetic research on kveik strains.
- Analysis of farmhouse yeast (kveik) - overview of master thesis by Truls C. Rasmussen that characterizes several kveik yeast species/strains.
- Kveik: Norwegian farmhouse yeast - An introduction to kveik and an initial report of DNA analysis by NCYC from 2009.
- Kveik analysis report - 2014 DNA fingerprinting of two more kveik samples sent to NCYC; one sample could not grow in the lab. The other found three closely related strains of yeast and no bacterial infection (Sigmund Gjernes's Voss Kveik).
- Brewing with kveik - Sigmund Gjernes, a homebrewer in Norway, brews traditional Norwegian farmhouse ale with kveik.
- Hornindal: interviews and collecting kveik - An attempt by Lars to collect three more samples of kveik which would not grow in the lab.
- Kveik testing - Lars brews using 5 different samples of kveik he's collected, and compares tasting notes.
- Raw ale - Definition of "raw ale", and the methods used to brew it in historical and traditional farmhouse brewing.
- "Brewing Modern Raw Ales," Brewing Nordic blog.
Norwegian Farmhouse Ale (Maltøl)
- Garshol's English book, "Historical Brewing Techniques" in English, 2020.
- Garshol's book on Norwegian farmhouse ale, "Gårdsøl", 2016 - Garshol's book on kveik and Norwegian farmhouse ale (currently available in Norwegian only).
- Norwegian farmhouse ale styles - An overview of the different styles of Norwegian farmhouse ale.
- Norwegian farmhouse ale - A brief history of traditional Norwegian farmhouse brewing (Lars refers to it as "homebrewing"), and what it is like today.
- Maltøl, or Norwegian farmhouse ale - An updated description of Norwegian farmhouse ale (broadly called "Maltøl"), substyles (Vossaøl/Hardangerøl, Råøl, Stjørdalsøl, and others), where they are being brewed today, and to what extent they preserve traditional processes.
- A guide for visitors to finding farmhouse ale in Norway.
- Norwegian Ethnological Research - Garshol's own research of the data that formed the basis for the definitive book on Norwegian farmhouse ale, Odd Nordland's "Brewing and beer traditions in Norway," published in 1969.
- Herbs in Norwegian farmhouse ale - Survey analysis of herbs used in traditional Norwegian farmhouse ale.
- Norway: climate and ingredients - Survey analysis of the distribution of brewing malts in traditional Norwegian farmhouse ale.
- MTF thread on species of juniper to use for farmhouse styles beers, and which are poisonous.
- "Heimabrygg, Vossaøl, Hardangerøl and Sognøl – The Farmhouse Homebrews of Western Norway," by Mika Laitinen.
Farmhouse Ale in Other Countries
- See Landrace Yeast.
- Traditional farmhouse brewer, maltster, and Gotlandsdricke from Gotland.
- "How to Brew Keptinis", a Lithuanian style of farmhouse ale using baked bread our of mash grains.
- See also this MTF thread on experiences of MTF members brewing this style of beer.
General Farmhouse Brewing
There is an annual festival created by the late William Holden celebrating the cultural traditions of European farmhouse brewing called the Kornølfestival. The festival is held in Hornindal, Norway in October with bus and hotel accommodations for visiting attendees.
- Watch the 2020 Kornølfestival Session 1 and Session 2.
- Youtube version: Session 1 and Session 2.
- Susan Verberg's informational highlights for the festival Part 1, Part 2, and Part 3.
- Chop n Brew interview with Lars Marius Garshol and Stig Jarle Seljeset about the festival:
- List of videos formerly maintained by the late William Holden in the Kveik Facebook group.
- Ivar A. Geithung's historic family farmhouse (Vasstrond'e Småbryggjarlaug).
- Chop And Brew playlist of videos on kveik, including information and farmhouse brewing demonstrations from Ivar A. Geithung.
- Terje Raftevold in Hornindal brewing raw farmhouse ale with kveik.
- "Drink friends old and dear, my ale shall bring good cheer". (video is about brewing traditional Norwegian Farmhouse beer in Hardanger, audio is in Norwegian)
- Richard Preiss's presentation and Q&A on kveik on the Doug Piper Crowdcast; 03/04/2020.
- Lars Marius Garshol's presentation and Q&A on kveik and farmhouse brewing on the Doug Piper Crowdcast; 04/15/2020.
- Interview with Lars Marius Garshol on the Escarpment Labs youtube channel with Richard Preiss; 04/20/2020.
- Lars Marius Garshol presentation on farmhouse brewing for the Brewers Association; May 2020.
- Homebrewing Condor playlist on how to use kveik (in Italian).
- Steps to making a Kornøl (Norwegian farmhouse ale) with Terje Raftevold (English subs):
- Traditional farmhouse malting and brewing, from Aurland, Sogn (audio is in Norwegian, but the imagery is still worthwhile if you do not understand Norwegian):
- Brewing with the elusive Hornindal-strain, done old school, no boiling, 2 days fermenting:
- Ivar A. Geithung making farmhouse ale at Vasstrond'e Småbryggjarlaug in Voss, Norway:
- RåØl (Raw Beer) Brewday with John Palmer at EIK og TID:
- Presentation by Lars Marius Garshol (in Norwegian):
- Omega Yeast Labs presentation on farmhouse brewing and using kveik:
- Presentation on kveik with Lance Shaner from Omega Yeast Labs, Damian Fagan, co-founder of Almanac Beer Co, and Chris Cohen:
- First ever North America presentation on kveik and farmhouse ales by Lars Marius Garshol at Burnt City Brewing in Chicago, 2019:
- Norwegian farmhouse brewer Ivar Geithung documents the brewing and fermentation of a traditional farmhouse brew that takes inspiration from other areas (Chop and Brew video; part 1 and 2):
- Author Susan Verberg demonstrating farmhouse brewing with hot rocks:
- The Ale Apothecary owner Paul Arney's documentary on Norwegian farmhouse brewing:
- Traditional Nordic Beer Drinking Vessels by author Mika Laitinen:
Additional Articles on MTF Wiki
- Landrace Yeast
- Raw Ale
- MTF Thread Highlights (search for 'kveik')
- Regional Styles
- "Historical Brewing Techniques" by Lars Marius Garshol.
- "Kveik" page on Wikipedia.
- Escarpment Labs blog post giving an overview of kveik and farmhouse beer styles.
- MTF thread on Lars Garshol sending Richard Preiss several strains of kveik for isolation and analysis.
- MTF thread on Alcolyzer readings (original gravity, final gravity, and ABV) of various farmhouse ales taken at Norsk Kornølfestival 2017. See also this spreadsheet.
- Beer and Brewing Traditions in Norway by Odd Nordland, Universitetsforlaget, 1969.
- Gårdsøl - det norske ølet by Lars Marius Garshol, Cappelen Damm, 2016. More info.
- "Lithuanian Countryside Yeast Tales," by ramtyns, 2012.
- Short History of Beer in Lithuanian, by Alastair Philip Wiper.
- "Characterization of genotype and beer fermentation properties of Norwegian Farmhouse Ale Yeasts," masters thesis by Truls C. Rasmussen.
- "Chain letters for Kveik" and Kveik flavor profiles.
- Norwegian brewer Ivar A. Geithung discusses his brewing process with kveik yeast on MTF.
- Sui Generis Blog on using Kveik for a black IPA recipe.
- "Kveik World Order" blog, by DeWayne Schaaf.
- Presentation notes and slides from a Lars Garshol presentation, by Ed Wray, 2018.
- Kveik Buy/Sell Group on Facebook.
- MBAA podcast interview with Richard Preiss of Escarpment Labs on Kveik.
- "How to Brew with Kveik" by Lars Marius Garshol and Richard Preiss; MBAA TQ Quarterly (MBAA member access only).
- "Kveik Training" by Sigurd Johan Saure in Sykkylven Norway; in person training on how to brew traditional Norwegian farmhouse ale at a traditional farmhouse brewery.
- "A Fire Being Kindled — The Revolutionary Story of Kveik, Norway’s Extraordinary Farmhouse Yeast," by Claire Bullen; an in depth introductory article on kveik.
- GBH Podcast: OL-011 Claire Bullen Reads "A Fire Being Kindled—The Revolutionary Story of Kveik, Norway’s Extraordinary Farmhouse Yeast".
- GBH Podcast: OL-013 Claire Bullen Reads, "The Land of Fire and Kveik — Farmhouse Brewing at the Crossroads in Voss, Norway".
- Bab.la Dictionary. Retrieved 01/21/2016.
- Ivar Geithung. Chop And Brew Youtube video. 09/21/2019. Retrieved 09/24/2019.
- [https://www.crowdcast.io/e/n2kbq0af Lars Marius Garshol. Presentation for Brewers Association. May 2020. Retrieved 05/18/2020
- <Lars Marius Garhol and Stig Bernsten. Milk The Funk Faecbook group thread on how to pronounce 'kveik'. 05/14/2019.
- Sveinung Marvik and Lars Marius Garshol. Kveik Facebook group. 01/03/2018.
- Lars Marius Garshol. Milk The Funk Facebook group reply on the meaning of the word "kveik". 12/29/2016.
- "Kveik" - what does it mean?. Lars Garshol. Larsblog. 10/29/2017. Retrieved 10/29/2017.
- Richard Preiss. Milk The Funk Facebook group thread on kveik. 06/19/2018.
- "Analysis of farmhouse yeast (kveik)." Larsblog. Lars Marius Garshol. 09/06/2016. Retrieved 09/06/2016.
- Kveik: Norwegian farmhouse yeast. Larsblog. 11/07/2013. Retrieved 01/14/2016.
- Lars Marius Garshol. "The juniper mystery". Larsblog blog. 02/02/2017. Retrieved 12/13/2018.
- Maltøl, or Norwegian farmhouse ale. Larsblog. 10/11/2016. Retrieved 01/14/2016.
- The Microbiology of Malting and Brewing. Nicholas A. Bokulich, Charles W. Bamforth. 2013. DOI: 10.1128/MMBR.00060-12.
- Traditional Norwegian Kveik Are a Genetically Distinct Group of Domesticated Saccharomyces cerevisiae Brewing Yeasts. Richard Preiss, Caroline Tyrawa, George van der Merwe, Kristoffer Krogerus, Lars Marius Garshol. 2018.
- Norwegian farmhouse ale. Larsblog. 10/27/2013. Retrieved 01/14/2016.
- How to Brew with Kveik. Lars Marius Garshol and Richard Preiss. MBAA Technical Quarterly, 2018 Q4.
- Varying opinions from MTF members, including Norwegians. Milk The Funk Facebook group chat about putting 'kveik' and where it is from on beer labels for mixed fermentation sour beers. 01/28/2019.
- Lars Marius Garshol. Kveik facebook group thread on kveik terminology. 11/03/2018.
- Richard Preiss and Lars Garshol. Milk The Funk post about the subtle differences in strains in some kveik cultures. 04/04/2019.
- Nadia Marlen Aasen. Growth, metabolism and beer brewing with kveik. Master's Thesis. Norwegian University of Life Sciences. 2020.
- Richard Preiss. Milk The Funk Facebook thread on kveik and the STA1 gene. 01/03/2018.
- Richard Preiss. Milk The Funk Facebook group comment about the two families of kveik yeast. 09/13/2018.
- Richard Preiss, Ingo Janssen, and Dan Pixley. Milk The Funk Facebook group on not treating kveik as "super yeast". 07/24/2019.
- Sensory data on kveik strains shared by Richard Preiss on MTF. 09/15/2016.
- Richard Preiss. Escarpment Labs blog post, "Crispy brewing with kveik: mind the pH gap." 11/26/2019. Retrieved 11/26/2019.
- Richard Preiss. Milk The Funk Facebook thread on kveik resulting in a lower pH for final beer. 11/26/2019.
- Richard Preiss. Milk The Funk Facebook thread on Escarpment Labs recommended kveik pitching rates. 07/27/2019.
- Adi Hastings. Milk The Funk Facebook thread on under-pitching kveik and potential off-flavors. 07/27/2019.
- Mark Schwarz. "Norwegian Kveik Strains and More with Omega Co-Founder Mark Schwarz" at Texas Brewing Inc. 05/14/2019. Retrieved 07/27/2019.
- Richard Preiss. Milk The Funk Facebook post on FAN requirements for kveik. 06/30/2019.
- Richard Preiss. Milk The Funk Facebook group thread on vitamin requirements for kveik. 08/03/2019.
- Dmitri Kits. "Are kveik thermophilic or thermotolerant: fermentation rates part 1." DEUX KANADIER BRÄU blog. 02/01/2021. Retrieved 02/03/2021.
- [https://www.deuxkanadierbraeu.com/post/omega-lutra-kveik-optimum-temperature-and-performance-review Dmitri Kits. "Omega Lutra kveik optimum temperature and performance review". DEUX KANADIER BRÄU blog. 05/27/2021. Retrieved 05/21/2021.
- Dmitri Kits. "Are kveik thermophilic or thermotolerant: fermentation rates part 2." DEUX KANADIER BRÄU blog. 02/01/2021. Retrieved 02/03/2021.
- Farmhouse yeast registry; FY #6 Lærdal. Lars Marius Garshol. Retrieved 05/06/2021.
- Justin Amaral. Milk The Funk Facebook group thread about lactic acid bacteria in kveik cultures and sensitivity to IBU. 06/05/2018.
- "Scandinavian Yeast Rings - the curious case of the Twisted Torus". Susan Verberg. 2019.
- Lars Marius Garshol. Twitter feed. 04/16/2019.
- Lars Marius garshol. Milk The Funk Facebook group post about using a kveik ring. 2017.
- Justin Amaral. Milk The Funk Facebook group post on kveikstokk and drying Brettanomyces. 08/16/2018.
- Dr. Bryan Heit. Sui Generis Blog post about dried kveik viability over time. 08/28/2019.
- Conversation with Lance Shaner and Lars Marius Garshol on MTF. 01/04/2016.
- Imperial Yeast. Facebook post on Imperial Yeast Facebook page. Retrieved 07/12/2019.
- Private correspondence with Inland Island sales staff by Dan Pixley. 04/05/2019.
- Mara Louise Young. Milk The Funk Facebook thread on Community Cultures Kveik cultures. 10/21/2019.
- Yeastlab (Brazil) website. Retrieved 10/18/2019.
- Robert Percival. Twitter. 11/06/2019. Retrieved 11/24/2019.
- "Kveik. Jasper Yeast Website.
- Escarpment Labs website, 09/10/2019. Retrieved 09/10/2019.
- "Dried Kveik - Rivenes". Mainiacal Yeast website. Retrieved 10/25/2020.
- Omega Labs website. "Announcing Lutra™ Kveik, A Shockingly Clean Kveik." Retrieved 06/14/2020.
- Omega Labs Facebook page comment on Lutra source kveik. 10/14/2020.
- Breno B Jorge. Correspondance with Bio4 staff; reported in Milk The Funk Facebook group. 10/22/2019.
- Bio4 website. Retreived 10/18/2019.
- Kveik Training website. Retrieved 11/10/2019.
- Chris Saunders. Milk The Funk Facebook post on Escarpment Labs Ebbegarden. 04/04/2019.
- Private correspondence with Richard Preiss by Dan Pixley. 05/27/2020.
- LevTeck website. Retrieved 10/18/2019.
- "Dried Kveik - Ner-Saure". Mainiacal Yeast website. Retrieved 10/25/2020.
- Allen Stone. Image of a White Labs poster. 04/14/2019.
- Richard Preiss. Milk The Funk Facebook thread on Escparment Labs "Kveik the World blend". 08/20/2019.
- Jeff Mello. Personal correspondence with Dan Pixley. 03/07/2019.
- Richard Preiss. Milk The Funk post on ITS sequencing OSLO. 08/-02/2019.
- Imperial Yeast Facebook post. 06/27/2019.
- WHC website. Retrieved 08/02/2019.
- Correspondance with Philip Nutt. Milk The Funk Facebook group post on WHC Labs' Ebbe kveik strain. 01/14/2020.
- Analysis of Sigmund Gjernes Voss yeast sample for Lars Marius Garshol, RÆLINGEN NORWAY. September 2014. Retrieved 01/20/2016.
- Lars Marius Garshol and Richard Preiss on Voss alcohol tolerance. Milk The Funk Facebook group. 08/04/2017.
- Richard Preiss. Milk The Funk Facebook group thread on the bitterness produced by Ebbegarden kveik. 12/04/2018.