Uninvited pellicle in secondary

[sanguine]

So while I'm fascinated by wild and sour brewing, I haven't done much of it, mostly because I don't have the space or budget to maintain a set of all-sour cold side equipment. Imagine my surprise, then, when yesterday I took a peek at the Scottish ale I had racked to secondary several days ago, and found what looks like it's definitely the beginnings of a pellicle. It looks even more pellicle-y today.

Now, gravity of this beer is what I would expect it to be for the recipe, and the sample I pulled out of the beer yesterday tasted fine, so I'm not too worried about it in the short term, but I am interested in what the hell this is and where it came from. To my limited knowledge it looks like a Brett infection, but I'm looking for a more expert opinion. In the process of investigating I opened the primary yesterday (which I, lazily, still hadn't cleaned) and the dregs on the bottom had a similar formation, accompanied by a tangy, somewhat acidic/vinegary smell. I've saved the dregs in an old whisky bottle in case they turn out to be worth culturing.

Generally, what is this and where could it have come from?

 

[RM-MN]

I don't know what it is but the nice wide space at the top of your beer is what sets you up for this. Next time if you don't want to make a sour, fill the carboy all the way to the neck so the CO2 dissolved in the beer will quickly fill the space above the beer or leave it in the primary.

 

[Yooper]

I don't know what it is but the nice wide space at the top of your beer is what sets you up for this. Next time if you don't want to make a sour, fill the carboy all the way to the neck so the CO2 dissolved in the beer will quickly fill the space above the beer or leave it in the primary.

Right. That much oxygen in a carboy of a finished beer allows oxygen loving microbes to take hold. I can't tell what it is- could be brett, but it could be pedio or lactobacillus as well- but I'd definitely take action NOW. I'd bottle, from under the pellicle, and drink the beer FAST before it turns into gushers.

 

[sanguine]

Now that you mention it, the only thing that's different about what I did is the extra air - I got lazy and just put the primary on a stool instead of the counter, and it didn't have quite enough elevation to push the last inch of beer out of the bottom. Live and learn, I suppose.

And now to empty out some bottles so I can salvage this batch, I suppose... a hard task, but somebody's gotta do it, eh?