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,→My beer looks infected
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 in the fermenter and see how it evolves. Optionally, you could pitch Roeselare or some other [[Mixed_Cultures|mixed culture]] or [[Brettanomyces|Brett]] culture and see how it turns out after a few months. 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 confidently identify contaminating microbes based on what a pellicle or other visual signs looks look like to the naked eye]]. Microscopy can identify microbes to some degree (genus level), but DNA analysis is needed for species-level identification.
(Please note that questions regarding accidental infections for beers that were intended to be clean beers are considered off-topic in the MTF Facebook group due to the number of these posts we would receive otherwise.)