Changes

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 <ref name="garshol_preiss_mbaa" />. 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 <ref name="preiss_strains" />. Strains within cultures probably arose due to mutations during cell division, as well as sporulation which kveik is more capable of than other domesticated yeast strains <ref>[https://www.facebook.com/groups/MilkTheFunk/posts/6929359520425536/?comment_id=6929468623747959&reply_comment_id=6933491356679019 Richard Preisse. Milk The Funk Facebook group thread about landrace yeast and sporulation. 05/16/2023.]</ref>. ''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 [https://www.frontiersin.org/files/Articles/409253/fmicb-09-02137-HTML-r1/image_m/fmicb-09-02137-t001.jpg this table from the paper]). A Master's Thesis by [https://nmbu.brage.unit.no/nmbu-xmlui/handle/11250/2681970?show=full 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'' <ref name="Aasen">[https://nmbu.brage.unit.no/nmbu-xmlui/handle/11250/2681970?show=full Nadia Marlen Aasen. Growth, metabolism and beer brewing with kveik. Master's Thesis. Norwegian University of Life Sciences. 2020.]</ref>.

[https://www.mbaa.com/publications/tq/tqPastIssues/2022/Pages/TQ-59-3-1015-01.aspx Carriglio et al. (2022)] compared propagation characteristics between WLP001 (California Ale Yeast), WLP830 (German Lager Yeast), and WLP518 (Opshaug kveik), using modern yeast propagation methods (12.5°P wort, 25°C temperature, 14.7 grams of yeast nutrient, constant aeration, recirculated with a pump, and with a total propagation time of 26 hours). The study measured attenuation, FAN consumption, final cell density, and final biomass production. They found that Opshaug did not uptake FAD any differently than the ale and lager yeasts. Opshaug had slightly less attenuation. They found that Opshaug kveik had a higher cell density than the ale and lager strain (~803 million cells per mL, versus ~461 million cells per mL for WLP001 and ~593 million cells per mL for WLP830). Aasen's Master's thesis showed similarly higher levels of cell density for kveik strains versus US-05 during fermentation ([[Kveik#Temperature_and_Growth_Rate|Temperature and Growth Rate]] below). The Opshaug kveik also nearly doubled the biomass production of ale and lager yeast <ref>[https://www.mbaa.com/publications/tq/tqPastIssues/2022/Pages/TQ-59-3-1015-01.aspx Comparison of Kveik with Conventional Saccharomyces Brewing Strains for Propagation Characteristics, Biomass Production, and Biomass Conversion Rate​​. MBAA TQ https://doi.org/10.1094/TQ-59-3-1015-01​. John C. Carriglio and Andrew J. MacIntosh. Food Science and Human Nutrition Department, University of Florida, Gainesville, FL, USA. 2022.]</ref>. These characteristics may or may not extend to other kveik strains, and different propagation temperatures may produce different results for all characteristics measured. See also [[Kveik#Temperature_and_Growth_Rate|Temperature and Growth Rate]] below.

* [https://www.youtubebrulosophy.com/watch?v=JQD45J0qqkU podcasts/the-bru-lab/episodes-001-to-100/ The Brü Lab Episode 033 - Kveik History & Genetics w/ Lars Marius Garshol.]* [https://www.youtubebrulosophy.com/watch?v=MbPRPPVz8xI podcasts/the-bru-lab/episodes-001-to-100/ The Brü Lab Episode 031 - Kveik Fermentation Temperatures w/ Dr. Richard Preiss.]* [http://thebrulab.libsyn.com/episode-086-fermentation-times-in-traditional-farmhouse-brewing-w-lars-marius-garshol The Brü Lab Episode 086 - Kveik Fermentation Times w/ Lars Marius Garshol.]

* Updates to Kveik research by Lars Marius Garshol at Kornølfestival 2022:: <youtube>g_Qnkh6c1cU</youtube> * 2023 Kornølfestival presentations in English:: <youtube>AuaGT2wYxNw</youtube> <youtube>uLhHGAlWyQI</youtube> <youtube>GWkPvOwQmMc</youtube> ==General Videos==

* Updates Lars Marius Garshol on Doug Piper podcast: "The Art & Science of Brewing: Norwegian Kveik and Farmhouse Traditions": <youtube>bREPI2p-d8g</youtube>* Norwegian farmhouse brewers Ivar Geithung and Johnny Pedersen visit Northern Brewer and Chop n Brew to Kveik research by brew four different traditional farmhouse brews:: <youtube>AgCkR6hG2uI</youtube> <youtube>Jf2sxucyXsM</youtube>* Lars Marius Garshol farmhouse ale presentation at Kornølfestival 2022EBCU:: <youtube>011OksAkGsM</youtube>* Lars Marius Garshol interview on Beer Ladies Podcast:: <youtube>g_Qnkh6c1cUbloKZdukwbs</youtube>

* [https://www.kveiktraining.com "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.]See also [https://www.youtube.com/watch?v=aKFFa1NcT0w this interview] with Sigurd.