Changes

''Brettanomyces'' can be pitched into a beer at many points in the beer's fermentation life cycle. If used as the primary fermenter, the beer that is produced is often fruit forward and not very ''funky''. A large cell count will be needed (somewhere between an ale and lager pitching rate). See the [[100% Brettanomyces Fermentation]] page for more information. If pitched into a beer that has already been fermented by [[Saccharomyces]], a wider range of flavors including the ''funkier'' flavors can be produced (see the [[Brettanomyces#Brettanomyces_Metabolism|Brettanomyces Metabolism]] section above). A small cell count of ''Brettanomyces'' is plenty for creating these flavors, and normally a starter is not necessary. See the [[Mixed Fermentation]] and [[Funky Mixed Fermentations]] pages for more information on using Brett in secondary.

When pitching just ''Brettanomyces'' from a commercial pure or blended culture and no other microbes, it is recommended to make a starter for the culture. If the ''Brettanomyces'' is being pitched into secondary, no starter is necessary unless the brewer suspects that the ''Brettanomyces'' has lost a lot of viability due to age, heat exposure, etc., or prefers higher cell count pitches.

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>.

Maintaining a temperature of 70°-80°F/20°-26°C should be adequate for most strains. ''Brettanomyces'' cell growth typically takes about 7-8 days to reach it's maximum growth <ref name="Yakobson_Propagation"></ref>. Thus, each step of a starter for Brett should be 7-8 days.

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>.

Given this information, many brewers historically have been using the lager pitching rates within online yeast pitching calculators for ''Brett'' starters (around 2000 mL, for example). Effectively, this means they have been pitching around 4 to 5 times the amount of ''Brett'' cells that they thought they were pitching. However, if this very high pitching rate is giving good results for brewers, it should continued be used. Exploration of ''Brett'' pitching rates for 100% Brett fermentations is something to be desired once we know what our pitching rates actually are, and many brewers have been pitching 4-5 times the pitching rate for lagers if they use an online yeast pitching rate calculator instead of counting the cells under a microscope.

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]".

Mark Trent's shaker platform (obtained from a used equipment outlet in Gilroy, CA called "Outback Equipment" ) used to create a semi-aerobic environment for ''Brettanomyces''. Mark built an insulated box for it, and added temperature control. He can propagate up to 7 liters. This is running at 80 RPM as described in ''The Brettanomyces project'' <ref name="chad_rpm"></ref><ref>[https://www.facebook.com/groups/MilkTheFunk/permalink/1048497155178498/ Discussion with Mark Trent on Milk The Funk. 4/2/2015.]</ref>.