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been teaching my bud how to brew, he's on brew 3 and has a coopers bavarian bubbling away

problem- he's told me he has strained it when pouring into fermenter, and now says he has a green-gray layer of scum on top of white krausen. I think this may be just the beloved scum ring, but am wondering if anyone has had this kind of mold grow whilst fermentation is in progress.

Could a mold live under the these conditions? the brew is still bubbling away so alcohol levels would surely kill any bacteria, right?

the only beer i've had trouble with was a bavarian lager, had some white patches on the surface of the beer, but bottled and drank anyway

b

The yeast that comes with the Bavarian Lager is actually a bottom fermenting lage yeast from a company called SafLager (S23) and acts much differently to every other kit yeast out there. Firstly it is bottom fermenting so you get a thick heavy layer of yeast at the bottom of the fermentor. I am assuming your friend sprinkled the yeast on top of the krausen to rehydrate it, and due to the fact that there is little suface activity, and a large increase in krausen at what I am assuming are temps in the high teens or low twentys some of the yeast did not make it into the brew and is what your friend is seeing on the top.

just to clarify, i do know that he is using Saflager (S-23) and that its bottom fermenting, but he didnt pitch over a krausen (?), he pitched straight onto the wort and water mix

maybe my terminologies are being mixed up, but i know he hasnt repitched, just one pitch and bubbling right away he told me

thanks
b

Did he use any additional hops? If so, he'll definitely have green scum on top of his krausen. Even if he didn't, I wouldn't stress too much, sounds pretty normal to me. All that gunk will end up sticking to the side of his carboy and he'll have a nice beer.

Noodles wrote:Did he use any additional hops? If so, he'll definitely have green scum on top of his krausen. Even if he didn't, I wouldn't stress too much, sounds pretty normal to me. All that gunk will end up sticking to the side of his carboy and he'll have a nice beer.

This would have been my next guess as well, though the "gray" part of the description still makes me think it is more likely to be yeast, it very well could be hops.

Noodles is right, nothing to worry about, it will stay in the krausen and either stick to the sides or be left behind when bottling.

thanks guys, keep up the great info and brews!

b

I think the Coopers Bavarian uses S-189, but I could be mistaken. I also think it sounds like some hop residue on top (if some were added)

Canbrew wrote:I think the Coopers Bavarian uses S-189, but I could be mistaken. I also think it sounds like some hop residue on top (if some were added)

S-189 would make more sense, but I had always heard it was S-23.

s- 189