Changes

===Starter Information===

There are generally two approaches to handling ''Brett'' starters. The first is to use a stir plate set to a low RPM for 7-8 days, cold crash for a few days, and then decant the beer before pitching the sedimented yeast. The second approach is to use an orbital shaker set to 80 RPM to create a ''semi-aerobic'' environment (this means that the oxygen levels are low, but also not non-existent) for 7-8 days as described in ''The Brettanomyces project'' <ref name="chad_rpm">[http://www.brettanomycesproject.com/dissertation/propagation-and-batch-culture-growth/propagation-methods/ Yakobson, Chad. The Brettanomyces Project. Propagation and Batch Culture Methods. Retrieved 2/18/2015.]</ref>, cold crashing can be skipped, and the entire starter is pitched into the wort. An alternative to the second approach is to give the starter an initial dosage of pure O2, and then to cover it with foil so that oxygen can slowly diffuse into the starter <ref>[https://www.facebook.com/groups/MilkTheFunk/permalink/1019859158042298/?comment_id=1020313737996840&offset=0&total_comments=24&comment_tracking=%7B%22tn%22%3A%22R6%22%7D Conversation with Nick Impellitteri on MTF in regards to semi-aerobic starters. 2/16/2015.]</ref>.

This presents a sort of "catch 22" when growing ''Brett'' in a starter. The brewer must weigh the pros and cons of how much aeration to provide. If the ''Brett'' is going to be used in a [[100% Brettanomyces Fermentation]], for example, then a stir plate may be the best choice. If the ''Brett'' is instead being pitched in secondary with the intention of long aging, then having a high cell count isn't as necessary and the risk of adding more acetic acid/ethyl acetate to an aging beer is greater. If a lot of acetic acid is produced during the starter, it is advised to cold crash and decant the starter. ''Brett'' can have a difficult time flocculating and settling out, even when cold crashed. The brewer may need to allow a few days for the cells to fully sediment <ref>[https://www.facebook.com/groups/MilkTheFunk/permalink/1099473923414154/?comment_id=1099522943409252&offset=0&total_comments=25&comment_tracking=%7B%22tn%22%3A%22R%22%7D Conversation with Richard Preiss of Escarpment Yeast Labs on MTF. 6/26/2015.]</ref>. Additionally, ''Brett'' that is cold crashed may be slower to begin fermentation. If the brewer believes that the amount of acetic acid produced was insignificant, then cold crashing can be skipped and the entire starter can be pitched.

Current yeast pitching calculators for brewers are not adequate for determining ''Brett'' pitching rates based on starter volume size because the maximum cell density of ''Brett'' per mL of wort is 3 to 6 times the cell density of ''Sacch''. For example, a given ''Sacch'' strain may reach a cell density of 130 million cells per mL in a 1.040 wort (different ''Sacch'' strains can have different cell densities as well, although they are a lot lower than ''Brett'' overall). ''Brett'' cell density have been reported to be 600 to 885 million cells per mL in 1.040 wort depending on the species/strain <ref name="Yakobson_Propagation">[http://www.brettanomycesproject.com/dissertation/propagation-and-batch-culture-growth/propagation-results/ Yakobson, Chad. The Brettanomyces Project. Propagation and Batch Culture Results. Retrieved 2/17/2015]</ref><ref name="MarkTrent">[https://www.facebook.com/groups/MilkTheFunk/permalink/1114254011936145/ Conversation with Mark Trent and Lance Shaner on MTF regarding Brett pitching rates. 07-21-2015.]</ref>. Since yeast calculators are based off of ''Sacch'' cell density, using one of these tools for ''Brett'' starters will create an unexpectedly high cell count. There is not currently enough data to accurately determine starter volumes for ''Brett'', particularly because each strain and species has a different maximum cell density per mL of wort. However, pitching around 500-600 mL of a ''Brett'' starter for 5 gallons of 1.060 SG wort will achieve a pitching rate that is similar to lager yeast pitching rates, which has been recommended for [[100% Brettanomyces Fermentation]]. [[Omega Yeast Labs]] is currently working on a project to create a more accurate ''Brett'' pitching rate calculator (it will also contain pitching rate calculations for specific strains of ''Sacch'', which is something that current yeast pitching calculators do not include) <ref name="MarkTrent"></ref>.

For breweries with laboratory capabilities, "Malt Yeast Peptone Glucose" growth substrate has been shown to be a better substrate for growing an initial pitch of ''Brettanomyces''. Specifically, when grown in wort, ''Brettanomyces'' will often go through a 24 hour lag phase, a growth phase, another lag phase, and a second growth phase (all within 7-8 days). When grown in MYPG substrate, there is only a single growth phase and no lag phase, which has been reported by Yakobson to produce a larger cell count in the same amount of time <ref>[http://www.brettanomycesproject.com/2009/08/mypg-vs-wort-as-the-growth-substrate/ Yakobson, Chad. The Brettanomyces Project. MYPG Compared to Wort as a Growth Substrate. Retrieved 2/18/2015.]</ref>. Cells grown in MYPG also are better adapted to grow in wort <ref>[http://www.brettanomycesproject.com/dissertation/propagation-and-batch-culture-growth/propagation-discussion/ Yakobson, Chad. The Brettanomyces Project. Propagation and Batch Culture Discussion. Paragraph 5. Retrieved 2/18/2015.]</ref>. Practical instructions for making this substrate can be found on Jason Rodriguez's blog, "[http://sciencebrewer.com/2011/04/29/wild-yeast-project-mypg-culture-media/ Brew Science - Homebrew Blog]".