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Mold on Krausen for sour beer

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chriwhit

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Mar 21, 2015
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Hi
Last week I started my first attempt at a sour beer using White Labs Belgian Sour Mix (contains Brettanomyces, Saccharomyces, and the bacterial strains Lactobacillus and Pediococcus.). Primary is in a bucket and this week I noticed my lid wasn't on secure so its basically been open fermentation for the last week. I sneaked a peak and can see what looks like mold on the krausen. Now I know that I am brewing with bacteria and a pellicle is supposed to form but I thought that it wouldn't form till several months in a secondary.
Given that the beer is supposed to be sour should I not be concerned?
Is this just natural when brewing with these strains?
I have to age this beer for a year in the secondary and don't really want to be wasting my time. Any help woudl be greatly appreciated.

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Mold is certainly not normal, and you are right, that does look like mold.

Is primary fermentation finished? Can you rack to a closed container (carboy) now? You might be able to salvage the batch. However, mold has a very low flavor threshold, even in sour beers. If you are lucky, it hasn't yet made a mess of the rest of the beer. You might be able to rack the beer out.
 
How loose was the lid? If it was on top but not pressed down, I wouldn't worry, sours do all sorts of weird things in my experience... and pelicles come in limitless shapes and sizes. Then, to add to the madness and mayhem, I've had pelicles forming in 3 days and had some not show up until 12 months. It's just weird stuff. Besides, as long as the fluid climbs over 1% it won't hurt you, I'd let it go and see what happens.

Next time, I suggest dregs from your favorite sour brewery. This will give you a higher sour punch. Alot of commercial sour strains just don't have as much of a kick.
 
Thanks for the advice.

Its not quite time to rack to secondary yet.

Yes the lid was on top just not firmly pressed down.

Electrolight when you say "as long as the fluid climbs over 1% it won't hurt you" You mean alcohol %? I'm just returning to the world of homebrewing after a 2 year hiatus and even then I was an amateur so I want to make sure I am not missing anything. If you do mean alcohol % then I'm safe. OG was at just over 1.05 and I am at 1.02 now

Thanks again
 
Yes, i read more than once that if it climbs above 1% ABV (I can't remember if it was 1.02% or .98. But it was so close my head just recalls 1%), then no pathogens that are harmful for consumption, will survive. But yeah, if you don't have an unusually moldy house or fermentation room, I'd bet it would be just fine anyhow. And if it was mold that snuck in there, it won't kill you to try it.
 
If you believe it is mold, rack from under it. I'd do it as soon as possible. Take a sample and taste it.
 
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