13,700
edits
Changes
no edit summary
See also:
* [https://www.facebook.com/groups/MilkTheFunk/permalink/2101419559886247/?comment_id=2101443939883809&comment_tracking=%7B%22tn%22%3A%22R0%22%7D MTF subthread on bacterial infections in kveik.]
==Kveik Ring/Kveikstokk and Drying==
[[File:Kveikstokk.JPG|thumb|300px|right|Kveikstokk with yeast slurry on it. Images provided by [https://www.facebook.com/groups/MilkTheFunk/permalink/2237938229567712/ Antonio Golia ("Homebrew Condor").]]]
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 <ref name="garshol_preiss_mbaa" />. 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" <ref>[https://www.academia.edu/38819003/Scandinavian_Yeast_Rings_-_the_curious_case_of_the_Twisted_Torus "Scandinavian Yeast Rings - the curious case of the Twisted Torus". Susan Verberg. 2019.]</ref>, or more specifically called a "gjærkrans" or "yeast wreath" in Norwegian when used for yeast <ref>[https://twitter.com/larsga/status/1118151239173328896 Lars Marius Garshol. Twitter feed. 04/16/2019.]</ref>) 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 <ref>[https://www.facebook.com/groups/MilkTheFunk/permalink/1505143962847146/?comment_id=1505145579513651&reply_comment_id=1505163232845219&comment_tracking=%7B%22tn%22%3A%22R%22%7D Lars Marius garshol. Milk The Funk Facebook group post about using a kveik ring. 2017.]</ref>. 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 <ref>[https://www.facebook.com/groups/MilkTheFunk/permalink/2237938229567712/?comment_id=2237959286232273&comment_tracking=%7B%22tn%22%3A%22R%22%7D Justin Amaral. Milk The Funk Facebook group post on kveikstokk and drying ''Brettanomyces''. 08/16/2018.]</ref>.
===Drying Instructions===
* [https://www.facebook.com/groups/MilkTheFunk/permalink/2237938229567712/?hc_location=ufi MTF thread with images of using a kveikstokk.]
* [https://www.facebook.com/groups/MilkTheFunk/permalink/2329264870435047/ MTF thread on drying kveik on parchment paper.] See also this [http://mutedog.beer/blog/how-to-dry-yeast post by Matt Spaanem on drying yeast (including some wild yeast strains) on parchment paper].
* [https://www.facebook.com/groups/MilkTheFunk/permalink/2257085904319611/ MTF thread on successfully drying Omega Yeast Lab's Hornindal kveik using a dehydrator.]
* [http://suigenerisbrewing.com/index.php/2019/04/25/drying-kveik-2-months/ Bryan Heit's drying instructions using a jerky dehydrator and viability testing of dried kveik over a few months (see previous parts as well).]
* [https://www.facebook.com/groups/MilkTheFunk/permalink/2858608184167377/ Rodrigo Borges de Azevedo's method of drying with 100% cotton or cotton blended with linen or polyester.]
* [http://www.garshol.priv.no/blog/291.html "Brewing with kveik" by Lars Garshol, with an example of using a yeast ring.]
* [http://mutedog.beer/blog/kveikstokk-beer/ Matt Spaanem's blog post on using a smaller kveikstokk for a wild caught yeast culture.]
* [https://homebrewingcondor.blogspot.com/2018/08/conservare-il-kveik-su-legno-kveikstokk.html Antonio Golia's write up on making and using a kveikstokk (in Italian; use an online translator).]
===Using Dried Kveik, Pitching Rates, 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. [http://suigenerisbrewing.com/index.php/2019/08/28/drying-kveik-the-grand-finale Microbiolgist 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 hps are not toxic to yeast, a high content of hops could further stress the yeast), using a dehydrator that had high and fluctuating tmperatures intead 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 <ref name="garshol_preiss_mbaa" /><ref>[http://suigenerisbrewing.com/index.php/2019/08/28/drying-kveik-the-grand-finale Dr. Bryan Heit. Sui Generis Blog post about dried kveik viability over time. 08/28/2019.]</ref>.
===History and Crafting How To's===
* [https://www.academia.edu/38819003/Scandinavian_Yeast_Rings_-_the_curious_case_of_the_Twisted_Torus "Scandinavian Yeast Rings - the curious case of the Twisted Torus," by Susan Verberg, 2019.]
* [https://www.facebook.com/groups/MilkTheFunk/permalink/2236226959738839/ MTF thread on building a kveik ring.]
* [https://poppylandbrewer.blogspot.com/2016/01/making-yeast-ring.html?m=1 Poppyland Brewer instructions on how to build a kveik ring.]
* [http://www.georgehart.com/rp/torzle/torzle.html Instructions on building a kveik ring and history information by George Hart.]
* [http://www.garshol.priv.no/blog/264.html "Kveik: Norwegian farmhouse yeast" by Lars Garshol, with images of ancient kveikstokk.]
* [https://www.facebook.com/groups/MilkTheFunk/permalink/1505381572823385/ MTF thread on an old kveik ring from Vågå that was sent to hopefully revive the old dried kveik on the ring.]
===Kveik Rings for Sale===
* [https://www.facebook.com/story.php?story_fbid=2013305902258162&id=1521916121397145 Tim Oelke of Suds n' Sawdust offers kveik rings in the US for sale.]
* [https://www.facebook.com/groups/MilkTheFunk/permalink/2464496793578520/?comment_id=2464565213571678&comment_tracking=%7B%22tn%22%3A%22R%22%7D Craft Labs in Sweden offers kveik rings off and on; contact info at craftlabs dot se.]
==Commercial Availability==
This is a summary of commercially available kveik cultures. See the above descriptions, the [http://www.garshol.priv.no/download/farmhouse/kveik.html kveik 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 will be denoted in the Notes column). Note that strain information can be misleading because 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 [[Kveik#Recent_Yeast_Lab_Analysis_and_Commercial_Availability|Recent Lab Analysis]] above) <ref name="preiss_strains" />. Commercially available non-kveik landrace farmhouse yeast are listed on the [[Landrace Yeast]] page.
* [https://www.facebook.com/groups/MilkTheFunk/permalink/2530669523627913/ Fermenting at colder temperatures, including lager temperatures.]
* [https://www.facebook.com/groups/MilkTheFunk/permalink/2783318115029718/ Discussion on blending different kveik isolates or original kveik cultures.]
==Videos==