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A: Usually contaminated beers do not give favorable results. Exceptions occur rarely from wild contamination. If the contamination was from a cultured ''Brettanomyces'' that originated from equipment that was used for purposefully mixed fermentations, then the contaminated beer might turn out well. Otherwise, the chances of a wild contamination turning out good are very low. The best advice is to smell a sample of the beer, and if it does not smell good then dump the batch and brew a sour/funky beer on purpose (if the fermentation produces a fair amount of alcohol, it can be safely tasted after a month. See [[Wild_Yeast_Isolation#Safety|Safety]] for more information). If you have space and time and want to simply learn what will happen with accidentally contaminated beer, then feel free to keep the beer and see what happens. Optionally, you could pitch Roeselare or some other [[Mixed_Cultures|mixed culture]] or [[Brettanomyces|Brett]] culture and see how it turns out. Another option if the beer still tastes fine and you don't want to risk additional off-flavors would be to pasteurize the beer at 180°F for 5 minutes. However, in the experience of most experienced sour beer brewers, this is not an efficient use of fermentation space. We recommend not wasting your time/fermentation space with accidental infections that show signs of off-flavors. Instead, use that space to brew an intentionally sour/funky beer and increase your chances of success. As far as knowing what infected the beer based on what a pellicle looks like, the short answer is that [[Pellicle#Pellicle_Appearance_as_a_Microbe_Identifying_Indicator|you cannot identify contaminating microbes based on what a pellicle looks like]].
(Please note that questions regarding accidental infections are considered off-topic in the MTF Facebook group due to the number of these posts we would receive otherwise.)
==Is this mold==