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Kveik

1 byte added, 23:34, 1 November 2019
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Pitching rates for kveik are also one of the unique things about these cultures. In order to express the yeast fermentation profile more, 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 [http://wyeastlab.com/pitch-rates 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 <ref>[https://www.facebook.com/groups/MilkTheFunk/permalink/2808232119204984/?comment_id=2808521072509422&reply_comment_id=2812164392145090&comment_tracking=%7B%22tn%22%3A%22R%22%7D Richard Preiss. Milk The Funk Facebook thread on Escarpment Labs recommended kveik pitching rates. 07/27/2019.]</ref>. 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 <ref>[https://www.facebook.com/groups/MilkTheFunk/permalink/2808232119204984/?comment_id=2808521072509422&reply_comment_id=2812793862082143&comment_tracking=%7B%22tn%22%3A%22R%22%7D Adi Hastings. Milk The Funk Facebook thread on under-pitching kveik and potential off-flavors. 07/27/2019.]</ref><ref>[https://youtu.be/7HVms3HSc9I?t=3803 Mark Schwarz. "Norwegian Kveik Strains and More with Omega Co-Founder Mark Schwarz" at Texas Brewing Inc. 05/14/2019. Retrieved 07/27/2019.]</ref> (~1:03:20 mins in). Oxygen should be at least in the 5-8 ppm range, although 10-12 ppm might be beneficial. [[Kveik#Kveik_Ring.2FKveikstokk_and_Drying|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 [http://www.garshol.priv.no/blog/367.html 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 <ref name="garshol_preiss_mbaa" />. 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) <ref>[https://www.facebook.com/groups/MilkTheFunk/permalink/2601801236514741/?comment_id=2602693406425524&reply_comment_id=2758757460819117&comment_tracking=%7B%22tn%22%3A%22R%22%7D Richard Preiss. Milk The Funk Facebook post on FAN requirements for kveik. 06/30/2019.]</ref><ref>[https://www.facebook.com/groups/MilkTheFunk/permalink/2825984810763048/?comment_id=2827018853992977&comment_tracking=%7B%22tn%22%3A%22R%22%7D Richard Preiss. Milk The Funk Facebook group thread on vitamin requirements for kveik. 08/03/2019.]</ref>.
[[Escarpment Laboratories]] presented the first [https://www.escarpmentlabs.com/single-post/2019/11/01/The-impact-of-pitch-rate-on-kveik-ferments 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 [https://www.facebook.com/groups/MilkTheFunk/permalink/2593762590651939/?comment_id=2593908627304002&reply_comment_id=2594146987280166&comment_tracking=%7B%22tn%22%3A%22R%22%7D 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. The strains were fermented at 20ºC (the lab would have preferred to ferment at a warmer temperature, but they were limited due to laboratory space). The pitch rates were '''1 M/mL''' (1 million cells mL, 10% of a typical pitch rate), '''7 M/mL''' (7 million cells/mL, 70% of a typical pitch rate), and '''10 M/mL''' (10 million cells/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.

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