13,594
edits
Changes
m
no edit summary
Major yeast labs will often store yeast in a -80°C laboratory freezer in a media/glycerol solution, however, this option is generally not practical for brewers <ref>[https://en.wikipedia.org/wiki/Cryopreservation Cryopreservation. Wikipedia. Retrieved 07/07/2016.]</ref>. The next best option for long-term storage of ''Brettanomyces'' is freezing with 10% glycerol in a home freezer, however, the effects of storing yeast at such a high and often variable temperature have not been evaluated scientifically. Traditionally ''Saccharomyces'' yeast has been stored on slants held in a refrigerator and can provide storage for a few months up to 2+ years, depending on the type of slant used (using mineral oil in slants has been shown to extend the life of stored ''Saccharomyces''). Homebrewers, however, have reported poor survival of ''Brettanomyces'' on slants. Data from a MTF member showed promising results by buffering the slant media. In this data, Brettanomyces has stored well for up to 100 days on the buffered media. It is not known for how long viability will remain high on buffered slants. For instructions on how to make slants at home capable of storing any microbe for potentially 2+ years, [http://suigenerisbrewing.blogspot.com/2015/11/easy-home-yeast-banking-and-video.html see Bryan's video on Sui Generis Brewing (requires a pressure cooker)]. Agar plates are the least effective solution and have been observed anecdotally to reduce the viability of ''Brettanomyces'' over a few months <ref>[https://www.facebook.com/groups/MilkTheFunk/permalink/1083075848387295/?comment_id=1083272091701004&offset=0&total_comments=13&comment_tracking=%7B%22tn%22%3A%22R0%22%7D Conversation with Matt Humbard, Ritchie Preiss, and Jeff Melo on MTF. 6/4/2015.]</ref><ref>[https://www.facebook.com/groups/MilkTheFunk/permalink/1115768398451373/?comment_id=1115817201779826&offset=0&total_comments=34&comment_tracking=%7B%22tn%22%3A%22R9%22%7D Conversation with Nick Impellitteri on MTF regarding storing Brett on agar plates. 7/24/2015.]</ref>.
Perhaps the best method for storing ''Brettanomyces'' long term is in sterilized (autoclaved or pressure cooked) wort or MYPG. Although not as ideal as freezing with glycerol at -80°C, this is the most practical way to store ''Brettanomyces'' for brewers without a lab freezer. Regarding temperature, it has been shown that cold storage for as long as a month is better than room temperature. However, after one month ''Brettanomyces'' appears to be more viable when stored at room temperature. More data is required before assuming this is the case with all strains of ''Brettanomyces''. Chad Yakobson noted that after storing ''Brettanomyces'' in a refrigerated environment (we don't know how Chad was storing the ''Brettanomyces'' cultures when he observed this, for example on agar plates or slants or something else.), after 6 months the ''Brettanomyces'' would die. If ''Brettanomyces'' is stored cold, it will be very sluggish and slow to start fermentation. Making a starter is highly recommended if the ''Brettanomyces '' culture has been stored cold <ref>[http://youtu.be/AjVOzBtE27Y?t=43m Yakobson, Chad. Presentation at 2012 Music City Brew Off. At 43:00.]</ref>.
In order to explore Yakobson's anecdotal observations in a more controlled manner, Mark Trent performed an experiment on storing one strain of ''Brettanomyces'' in wort, MYPG, buffered wort (buffered to prevent a drop in pH), and buffered MYPG, and compared storage of the ''Brettanomyces'' in each of the storage solutions at room temperature versus cold temperatures for 100 days. This single ''Brettanomyces'' strain survived best in unbuffered MYPG at room temperature, and second best in unbuffered wort at room temperature, and survived less in cold storage conditions for all media. See the [[Brettanomyces Storage Survival Experiment]] for more details. Therefore, when storing ''Brettanomyces'' for one month or less in wort (or perhaps beer), it should be stored refrigerated. However, if the ''Brettanomyces'' will be stored for more than one month in wort (or perhaps beer), it should be stored at room temperature (until more data improves our understanding). Note that at best these storage techniques will decrease viability greatly (80%+) within 3 months, and a starter should be used to try and revive the culture before use <ref>[[Brettanomyces_Storage_Survival_Experiment]]</ref>.
Occasional feeding has been shown to keep ''Brettanomyces'' alive in beer for brewers who do not have a lab, however , many variables may come into play as far as how effective this will be for individual strains and in different environments. Although no research has been done to indicate what the best practices are for feeding ''Brettanomyces'' to keep it alive in beer, we recommend trying this method: every 3-6 months swirl the vessel so as to suspend all of the yeast and then decant 70-90% of the beer and suspended yeast slurry, and replace it with a 1.040 starter wort with yeast nutrients. This method will discard a lot of the old yeast cells, while retaining enough living cells for replication <ref>[https://www.facebook.com/groups/MilkTheFunk/permalink/1345924532102424/?comment_id=1345979272096950&reply_comment_id=1346020438759500&comment_tracking=%7B%22tn%22%3A%22R3%22%7D Conversation with Mark Trent and Richard Preiss on MTF regarding occasional feeding of ''Brettanomyces'' to keep it alive. 07/07/2016.]</ref>. Some strains may survive extended periods of aging in beer, however , their viability and vitality will be greatly reduced over time. Interestingly, ''Brettanomyces'' remains '''more''' viable over time if it was co-fermented with ''S. cerevisiae'' than if it was fermented without the presence of ''S. cerevisiae''; i.e. [[100%25_Brettanomyces_Fermentation|100% ''Brettanomyces'' beers]] or ''Brettanomyces'' and ''Lactobacillus <ref name="Hubbe" />.
Another method for storing ''Brettanomyces'' has reportedly worked for MTF member Justin Amaral. This method involves storing the culture in isotonic sodium chloride. ''Brettanomyces'' cultures have been reported by Amaral to survive at least for 6-7 months. This includes other microbes as well (RVA Orchard Brett, ECY Dirty Dozen, Bright Yeast Labs Brett Chateaux, ''T. delbrueckii'', ''L. plantarum'' isolated from goodbelly, Omega Lacto blend, ''Pediococcus damnosus'', Bootleg Biology Sour Weapon, and Funk Weapon 2 and 3, and a ''Brettanomyces'' isolate from Yeast Bay). For more information on this method, see [https://eurekabrewing.wordpress.com/2012/09/05/yeast-banking-3-isotonic-sodium-chloride/ this Eureka Brewing blog article] <ref>[https://www.facebook.com/groups/MilkTheFunk/permalink/1631448736883334/ Amaral, Justin. Milk The Funk Facebook group. 03/30/2017.]</ref>.