The smell was slightly acidic, but not particularly so for a porter. The taste was also very slightly tart, but it is hard to say if that was unusual or not, as I am not very good at discerning much from warm mucky uncarbonated nasty “first bit diverted from going into the keg” beer, and I was trying to taste acetic acid.
Mold can usually be skimmed off the top, then rack the beer into a keg. If the beer tastes bad then dump it. This is caused by poor sanitation in most cases and/or you have a higher incidence of mold floating around in your brewery.
I know it is hard to tell from the picture, but it isn’t fuzzy like mold, it was more like a plasticine film that had some bubbles in it. It didn’t smell like vinegar, just like dark beer.
I’ve had some white flaky films that break up after the krausen has subsided and the beer’s set for a few days, weeks even. If this is the case then the beer’s fine. Steady your hand, focus and use a flash when posting this type of pic. Cause this looks like fuzzy bubbles. ???
Yep, hate to break it to you but that looks like acetobacter. Does the film have a waxy consistency? Have you seen any fruit flies around the fermenter? This is fruit fly season. I think I lost a batch 2 or 3 years in a row late sept/early oct. once. All in plastic buckets.
I’ve seen this several times before. In my experience it makes the beer taste like turpentine and dry as a bone. Probably a dumper, unfortunately. And for me, it’s been caused by everything from poor sanitation to dry hopping to fruit flies. Dang bacteria cling to hops and bugs and screw up your beer. Nevertheless, it’s a good idea tasting the beer and deciding if this is something you’re willing to drink a lot of very fast before it gets any worse (which it probably will), or whether it’s just a dumper.
Yeah, the fruit flies have been congregating like a Biblical plague around here . . I had one carboy of Dubbel that may have succumbed to the hordes . . .
I’ve never had a fruit fly make it through a wet airlock in a carboy. With buckets the airlock doesn’t matter, they can get through the seals (or their larvae can).
Acetobactor likes to form a plastic like film over the surface of the beer. The picture doesn’t show that. However, if it the beer is taking on an acetic aroma and has a vinegar-like flavor then it is an acetobactor infection for sure.
I can’t be certain, but I think it may have happened when the yeast popped the top on the 3 piece airlock during a vigorous ferment phase. Not sure how long it was exposed before I found it, but apparently long enough . .
It takes a while for the beer to start smelling like vinegar though. I’ve had acetobacter infections that actually didn’t taste terrible. No sourness noted. Not something I could ever enjoy, but not much sourness going on either. It takes along time for acetobacter to fully convert the alcohols over to vinegar.
Be certain though that acetobacter never travels alone. It is most certainly more than one infection.
Acetobacter is aerobic so it can’t live once you purge the o2 with co2. So if you want to try and rescue the beer the sooner the better. Not that I would, I’d dump it.