why does my APA smell of acetone?

Originally posted by harrisoni
Can’t decide between too warm and perhaps too much oxygen in the secondary.

Oxidation =/= Acetone

Besides, oxidation takes a while to show up.

Originally posted by VsXsV
I’ve stopped using US-05 due to getting acetone-like notes. It usually starts producing those notes if you ferment it too warm. It’s a good yeast if you use it below 21-22 degrees centigrade, otherwise I don’t like it at all.

I would go a little lower even. I like to ferment this yeast at 66F and find if it goes over 68 (during summer months, which is why I am switching over to making saison beers in the summer), I get some off flavor wierdness lurking in the background when really trying to detect it. Of course these are the temps my stick on thermometer are saying - so who really knows the accuracy of those temps...

The exact same thing happened with my second batch of a wheat beer a few weeks ago (bucket smelled like nail polish but the beer itself smelled, tasted fine). I didn’t use a secondary. The most likely culprit was heat; I didn’t realize a guest had closed the window in the room my beer was fermenting until it had been closer to 75-80 for 3 days.

You were painting your nails whilst brewing?

We did have a hot spell in england so perhaps it was that. oh well its in bottle now and i will open the first one in a couple of weeks time. i shall just have to pretend its a dry acetone perry whilst i drink it.

Originally posted by flabeer
The good news is, with time Ethyl acetate will diminish. May take several months if you’re willing to wait.

The even better news is that it has now almost completely cleared up and it’s very drinkable now. Only took 4 weeks to clean it up in bottle. Ok there is a little left, but give it another 2 weeks and I’d say it would have gone completely. Turned out to be a decent APA that I actually enjoy drinking when I get home after work to slake my thirst.

It’s good to take a record of temperatures while fermenting so you can track what causes what and either replicate it or avoid it depending on the result. Two weeks in primary is a long time if the temperature went up. As a general rule, the higher the temperature the shorter the fermentation, and the longer the fermentation the greater awareness and control you’ll need on your temperature. If you haven’t done so yet, get a fish tank heater which will help you control the temperature, and put your fermentation vessel inside a larger container filled with water, and control the temperature of that water with the fish tank heater.

AFIK, US-05 = WLP001 = WY1056 = "Chico" strain.

High temps are not your friend.