Really Hot Fermentation!

[BeeRad77]

I brewed a batch of Imperial Stout that went into the fermenter about 8:00pm, and put it in the usual spot in my upstairs closet. The room temp is right around 65F usually, and I have never had a problem I checked on this batch tonight for the first time and the blow off container was bubbling like jets in a hot tub. The thermometer sticker on the side wasn't even registering. I wondering if you guys think the batch is going to turn out bad. I have never had a fermentation get this hot, so I am not sure.

I put it in the garage, and after an hour the thermometer reads 78. I'm going to leave it there for a few more to let it cool to a reasonable temp. I pitched a 1.3 gallon starter of Wyeast London Ale yeast according to the Mr. Malty calculator, so maybe it just got so hot due to the large amount of yeast activity? It's definitely not too hot outside, there's snow on the ground.

 

[thegerm]

that's a fast fermenting yeast, but it's not going to raise the wort temp more than 5 degrees above ambient, assuming your wort was actually at ambient when you pitched.

if it was really fermenting in the 80s and ambient was really 65, I would deduce that you didn't chill the wort down far enough before you pitched?

you'll probably have some strong esters, especially with that yeast strain in the 80s. then again you didn't say what your OG was, so if you overpitched a bit, maybe there wasn't a lot of growth and ester production. let the yeast clean up after themselves as much as possible and see how it turns out.

 

[frankstoneline]

What was the temp when you pitched/was the fermenter hot to the touch (sometimes my carboy side thermometers dont read very well)?
It may develop some undesirable flavors, however some of that may be taken care of by time in the bottle, I brewed a big stout about a year ago and it got wild out of control, after a serious amount of bottle time it's tasting quite nice.
Bottom line, keep it in a constant heat environment, as moving it from one temp to another will stress the yeast and be prepared to wait if it has some off flavors.

 

[rorygilmore]

that's a fast fermenting yeast, but it's not going to raise the wort temp more than 5 degrees above ambient...

Only 5 degrees for a high-gravity beer? I've had a batch or two easily climb more than that.

 

[BeeRad77]

I pitched the yeast at 68 degrees, which is what I usually do. I'm guessing the ambient was a bit more. I use the closet in our office because the temp is pretty stable, but I found out my Mother in law had the heat up to 72 yesterday when I was gone, so who knows how hot it was in there. The OG was 1.104, which is right where it was supposed to be. I over pitched if anything, two smack packs in the starter. I should make her pay for the next batch.