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Brettanomyces

1,566 bytes added, 15:43, 17 September 2015
putting Mark Trent's Brett storage experiment back
Long term storage of ''Brett'' should be frozen with glycerol, rather than agar plates or slants, which have been observed anecdotally to reduce viability of ''Brett'' over time <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>. Chad Yakobson noted that after storing ''Brett'' in a refrigerated environment (agar plates or slants?), after 6 months the ''Brett'' would die. If ''Brett'' is stored cold, it will be very sluggish and slow to start fermentation. Non-pure cultures (such as beer bottle dregs with ''Brett'' in it) should be stored refrigerated. Making a starter is highly recommended if the ''Brett'' 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>.
[[File:Brett viability temp storage.jpg|thumb|350px300px|[https://www.facebook.com/groups/MilkTheFunk/permalink/1115768398451373/ Richard Preiss's results of storing Brett at different temperatures]]] [[File:Brett storage MarkTrent.jpg|thumb|300px|[https://www.facebook.com/groups/MilkTheFunk/permalink/1115768398451373/?comment_id=1145139948847551&offset=0&total_comments=69&comment_tracking=%7B%22tn%22%3A%22R9%22%7D Mark Trent repeated Richard Preiss's results of storing Brett at different temperatures, and also in different mediums.]]]
Yakobson's observations were not scientifically quantified and details of his process are lacking (how was the ''Brett'' stored?), as far as we know. Richard Preiss of [http://www.escarpmentlabs.com/ Escarpment Yeast Labs] shared the results of a controlled experiment on MTF that showed that BSI's ''Brett brux Drie'' and ''B. claussenii'' survived better in low ABV beer when stored at refrigeration temperatures rather than room temperatures, contradicting the anecdotal observations reported by Yakobson. The samples were grown in 1.040 DME wort until typical cell density was reached, and measured for >95% viability after growth with trypan blue stain and microscopy. 10ml samples of each were stored in sterile conical tubes for one month at different temperatures (4°C and 24°C). The samples were burped to avoid having head pressure as a variable. Trypan blue stain and microscopy were used to measure the viability after one month. After one month of storage at 4°C (39.2°F), the viability of ''B. claussenii'' was 92%, and BSI Drie was 72% viability. The samples stored for one month at 24°C (75.2°F) showed a significant drop in viability, with ''B. claussenii'' ending up at 40% and BSI Drie at 6% viability. This experiment also indicates that the viability of ''Brett'' strains/species after storage is strain/species dependent <ref>[https://www.facebook.com/groups/MilkTheFunk/permalink/1115768398451373/ Richard Preiss Brett storage experiment results on MTF. 7/24/2015.]</ref>.
 
Mark Trent repeated Richard Priess's experiment, but tested different mediums (wort, liquid MYPG, and water). Two ''Brett'' isolates, one from Orval and one from SARA Bernice, were grown in 10 degree Plato wort and MYPG. The isolates are labeled on the chat as "Brett O (Orval)" and "Brett T (Tim Clifford)" respectively. After growth was complete, 10 mL of aliquots were aseptically transferred to 15 mL centrifuge tubes. In addition, the Orval isolate was grown on a MYPG plate and 3 single colonies for each treatment were transferred to 1 mL of sterile RO water in a 2 mL glass tube. Each treatment was prepared in a duplicate and stored at either 22°C or 1°C. Viability was measured after 31 days. Data shown in the chart to the right. No other statistics were performed. All storage mediums shared results similar to Richard's results. This further shows that ''Brett'' survival is a function of temperature, with lower temperatures being beneficial towards survival <ref>[https://www.facebook.com/groups/MilkTheFunk/permalink/1115768398451373/?comment_id=1145139948847551&offset=0&total_comments=69&comment_tracking=%7B%22tn%22%3A%22R9%22%7D Conversation with Mark Trent on MTF. 09/10/2015.]</ref>.
Questions raised by MTF members in regards to these results:

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