How hot does fermentation get?!!!

I brewed a blueberry ale yesterday, and pitched a packet of Safale S-05 last night. I decided to put a submersible thermometer in there to see how hot it actually is in the middle of the storm, and this is what I saw when I got home today:



139 degrees!!! Holy crap! It's in a bucket of cold water too, but does it really get that hot in there from all the yeasties moving around?

I would have to say something is wrong with your thermometer. Fermentation temps can get a little over 5 degrees higher, at 139 your yeast would be dead...

Monster Mash said:

I would have to say something is wrong with your thermometer. Fermentation temps can get a little over 5 degrees higher, at 139 your yeast would be dead...

Click to expand...

x2, although I have had some get 10* hotter

I'm wondering if it's not that hot in there, but it's moving around so fast that it's fooling the thermometer. Otherwise I've been mashing at just above freezing.

LOL
139?
150 - 160 degrees F is the temperature at which you can get a second degree burn.

I don't think your thermometer is meant to be submerged where the probe hits the wire lead.

I did that with mine, and it read 189F after a few minutes, even ice cold water only dropped it 2 degrees.

I let it dry out for about 5 days, and it works again.

it's a digital oven thermometer, so I gotta be careful about letting it fall all the way into the brewpot.

What you have there is what I like to call a "mulled" fermentation.

Damn Fisher Scientific, last time I buy anything from them on lab money...