Beer Forum

So the batch of Belgian Dubbel has been fermenting for nearly 2 weeks. Fermentation has slowed and the beer is about ready for transfer to kegs. I noticed that the previously pleasant banana/bubble gum smell from the fermenter has been replaced in the past few days with a smell more resembling that of an old sock. Is this an indication of an infection? Or anything to be concerned with at all? Thanks. I know I'll find out in a couple of weeks when I drink it, but all advice is appreciated.

What yeast strain did you use? Fermentation temps?

More info would indeed be helpful.

Did you dry sock it?

Sure. Yeast was WLP500 Trappist High Gravity. It has been at a steady 70 degrees for 12 days and there was no dry socking.

Does it have any sulfur notes going on? Sometimes those belgian strains can kick out some sulfur during fermentation but they will usually clean up after themselves, even after packaging occurs.

I don't think there is any sulfur, but I am not the very good at detecting things specifically. I did notice that the smell was very similar to my leather watch band. I dropped the temp to 35 yesterday to cold crash, then watched in horror as my blow off tube dropped about 1/4 cup of sanitizer into the carboy. I'd guess that's pretty harmless aside from whatever gunk is living in the tube. Stressful hobby. Mostly I think I'm being paranoid hoping that this will be my best batch yet (1 year brewing, ~15 batches brewed, 4th Belgian batch).

That's why I don't cold crash carboys I doubt that 2oz of sani will be too big of a deal.

It's hard to pinpoint exactly what's going on & honestly I don't have a lot of experience with that yeast to pick up on any oddities.

From what I'm reading, I'm thinking you may have a wild yeast in there. It's hard to say without seeing it or tasting it, but that's my first thought from your descriptors. It just doesn't sound like a sulfur issue to me.

Yeah, if it smells like dirty leather then an infection is very likely. Do you have anyone nearby that could taste it for you to help you identify the off-flavor?