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Mixed Cultures

191 bytes removed, 02:33, 19 June 2018
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In the past, some yeast manufacturers (namely Wyeast) did not recommend making a starter for mixed cultures. Reasons varied from "throwing off the ratio of microbes" to "creating acetic acid". In regards to the first concern, throwing off the ratio of microbes will likely not be a real concern. It is possible that this will change the profile of the fermentation (for example the beer might turn out more sour because the lactic acid bacteria were allowed to grow more cells in the starter), but if treated properly all of the microbes will have a higher cell count after a starter is made, and the yeast (both ''Brettanomyces'' and ''Saccharomyces'') will be more viable after a starter. Pitching a second culture of fresh ale yeast isn't necessary with mixed cultures that have their own ''S. cerevisiae'', and making a starter ensures the cell count is high enough. However, some mixed cultures might not come with ''Saccharomyces'' out of the package, or in the case of a [[Mixed_Fermentation#Reusing_a_Sour_Yeast_Cake|re-using a sour yeast cake]] the ''Saccharomyces'' might be dead. In such cases the brewer may choose to pitch fresh ''Saccharomyces'' separately (see [[Mixed_Fermentation#Reusing_a_Sour_Yeast_Cake|re-using a sour yeast cake]]). Oxygen does not inhibit lactic acid bacteria in general, so this is generally not a concern.
In regards to If the concern about oxygen, oxygen does encourage acetic acid production in ''Brettanomyces'' (and some species of ''Lactobacillus'' such as ''L. plantarum''). Howeverpackage is fresh, then a starter can be decanted to remove the starter beer if it smells highly aceticis generally not required. Some brewers have reported If the package is nearing expiration or expired and buying a new package is not decanting the starter at allan option, and or if the small amount batch of acetic acid present doesn't make beer is much larger than what the package is intended for, then we recommend making a large impact on the final beer due to dilutionstarter for all mixed cultures (including Wyeast Roeselare). Therefore, in In general, it is good to use aluminum foil to cover the we recommend a 500-1000 mL starter instead of using an airlock(~1.040 OG with DME) for a 5 gallon batch. If Run a stir plate on the starter is going to be stored for longer than 2 lowest setting, or 3 weeks, then use an airlock to limit occasional manual stirring with no automatic stirring. If the acetic acid production and store it at refrigerator temperatures (long-term exposure to acetic acid and low pH will lower the vitality of package contains ''Brettanomyces'', then run the starter for 4-6 days; if the package does not contain ''SaccharomycesBrettanomyces'', and then run the starter for 24-48 hours. Do not use hops in the starter unless inhibiting the lactic acid bacteria)is desired. The viability of One may want to have an anaerobic starter in the microbes will get worse case that the longer the starter is stored (some strains of ''Brettanomyces'', saison yeast, and lactic acid bacteria might survive longer than regular are especially weak, and the brewer's wants to inhibit the yeast; a growth in the starter . Remember though that is 6+ months old yeast needs oxygen in order to grow viable cells <ref>[https://www.facebook.com/groups/MilkTheFunk/permalink/1660420660652808/?comment_id=1660436453984562&comment_tracking=%7B%22tn%22%3A%22R8%22%7D Pat Tkacz and Justin Amaral. Milk The Funk Facebook group. 04/21/2017.]</ref>. Pitching the entire starter should be treated like a fine, even if there is some considerable acetic acid production (see [[Mixed_FermentationBrettanomyces#Reusing_a_Sour_Yeast_CakeStarter_Information|sour beer yeast cake''Brettanomyces'' starters]]), so if although it is stored for more than 2 or 3 months, then a new starter should can also be made to make sure the cell count is high at pitching time. Letting chilled and the starter grow for 3-6 days with light agitation (either frequent manual stirring, a stirplate on a low setting, or an orbital shaker) before pitching is a good general rule of thumbbeer decanted if desired.
If In regards to the package is freshconcern about oxygen, oxygen does encourage acetic acid production in ''Brettanomyces'' (and some species of ''Lactobacillus'' such as ''L. plantarum''). However, then a starter is generally not requiredcan be decanted to remove the starter beer if it smells highly acetic. If Some brewers have reported not decanting the package is nearing expiration or expired starter at all, and buying the small amount of acetic acid present doesn't make a new package is not an option, or if large impact on the batch of final beer is much larger than what the package is intended for, then we recommend making a starter for all mixed cultures (including Wyeast Roeselare)due to dilution. In Therefore, in general, we recommend a 500-1000 mL it is good to use aluminum foil to cover the starter (~1.040 OG with DME) for a 5 gallon batchinstead of using an airlock. Run a stir plate on If the lowest settingstarter is going to be stored for longer than 2 or 3 weeks, or then use occasional manual stirring with no automatic stirring. If an airlock to limit the acetic acid production and store it at refrigerator temperatures (long-term exposure to acetic acid and low pH will lower the package contains vitality of ''Brettanomyces'', then run the starter for 4-6 days; if the package does not contain ''BrettanomycesSaccharomyces'' then run the starter for 24-48 hours. Do not use hops in the starter unless inhibiting the , and lactic acid bacteria is desired). One may want to have an anaerobic starter in The viability of the microbes will get worse the case that longer the starter is stored (some strains of ''Brettanomyces'', saison yeast, and lactic acid bacteria are especially weak, and the might survive longer than regular brewer wants to inhibit the 's yeast growth in the ; a starter. Remember though that yeast needs oxygen in order to grow viable cells <ref>[https://www.facebook.com/groups/MilkTheFunk/permalink/1660420660652808/?comment_id=1660436453984562&comment_tracking=%7B%22tn%22%3A%22R8%22%7D Pat Tkacz and Justin Amaral. Milk The Funk Facebook group. 04/21/2017.]</ref>. Pitching the entire starter is 6+ months old should be fine, even if there is some considerable acetic acid production (see treated like a [[BrettanomycesMixed_Fermentation#Starter_InformationReusing_a_Sour_Yeast_Cake|''Brettanomyces'' starterssour beer yeast cake]]), although so if it can also is stored for more than 2 or 3 months, then a fresh starter should be chilled and made to make sure the starter beer decanted if desiredcell count is high at pitching time.
See the recommendations below from smaller yeast labs below for examples of how to treat mixed culture starters.

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