Beer Forum

Any idea what is growing at the top of my secondary fermenter? It is an off-white film that looks dry rather than slimy, is not dusty or powdery, and seems to be one continuous piece. Similar to the skin that forms on top of heated milk, but bunched up as if it has grown outward in all directions and was forced to fold in upon itself like a human brain. Here's the picture:

I'll be first to plunk my neck on the block and say it looks like a "Pellicle" caused by Brett (wild yeast, I didn't do it). What's the beer?



Image stolen from Jim Liddle's Lambic site

The beer is a "kitchen sink" beer - just clearing out old ingredients. During fermentation, I had my first, unopened, vial of Brett sleeping upstairs in the fridge. I know that some people have dedicated equipment for bugs, but are you telling me I can't even keep the stuff on the other side of the house? (kidding)

Seriously, I've never used a wild yeast before..., though I cultured a starter of DeDolle Oerbier in december and tossed it. This beer is a third generation yeast cake of Kolsch yeast that came from perfectly clean beers and was first pitched in late January. Something must have gotten in there. I remember when I first started brewing in the early 90's, I read that I should not worry about a thin white film on the top of my beer, but this seems like more than that. I guess that I'll let it sit and see what happens. If it is a wild yeast, what should I next expect the pellicle to do? Won't it drop in six months?

Left undisturbed it could be a year before it falls. Three generations is starting to push it for re-pitching - for us home brewers anyway. Some folks go five or more, but I don't go more than two.

Sounds to me like (assuming the secondary carboy was well sanitized) when you racked it off the Saccharomyces yeast the Brett started doing it's thing. It might be a Brett but one or more of the bajillion yeast species floating around. Leave it and see what happens.

$10 says it'll be real thin and/or sour in a few weeks and you'll pour it out.

Don't pour it out! Let it go for a year.... your first lambic.


Mylo