Autolysis Causing a Soy Sauce smell?

[Betkefest]

I brewed my first all-grain munich style weiss beer using a Wyeast smack pack. I had good gravity readings and decent efficiency. The yeast were very active, and even with a 6.5 gallon carboy I had to use a blow-off tube (into a bucket with sanitized water) to manage the overflow of activity.

After a few days I switched back to an airlock. After about ten days I should have bottled the beer. But we went on vacation. I've let ales sit in my primary for a month in the past with no ill effects.

But there was a heat wave when we were gone, and my usually 75 degree kitchen hit 100 degrees a few days we were gone.

I bottled as soon as we returned. The beer tasted a little stale, but still had the banana/ester flavor I expect from a weiss.

Two weeks later, the beer isn't carbonating correctly, and I'm getting a smell I can only describe as "soy sauce."

Research points to autolysis - dead yeast - compounded by the heat and the relatively long time in the primary. Without the heat, the length of time in the primary might not have been a problem.

Anyway, this is convincing me that unless the beer is in a temperature controlled space, a longer time in the primary could be a crap-shoot!

 

[runningweird]

yes,temp control is a massively important factor.100 degrees will send any yeast into producing bad tasting stuff.

 

[Calder]

Higher temperature 'conditioning' on the yeast can lead to autolysis. If you had it you would have noticed it at bottling. I've personally experienced it as a very distinct smell of rubber (burn't rubber). I've never had it in a beer, but I store a lot of yeast in mason jars, and it develops over several months. It is very obvious.

Once racked of the yeast, it will not develop further, so you should have had it at bottling, and it is something that you can smell.

 

[Betkefest]

Calder, it might have been there at bottling and I might not have noticed it. It didn't taste quite right (as I mentioned, it tasted "stale"). It's been after a few bottles that my wife, actually, nailed down the soy sauce smell.
Anyways, my basement is consistently 60-65 in the winter, 70-75 in the summer. I will definitely ferment everything down there from now on, even if the forecast calls for mild weather!