Fermentation temp question

Hey folks, after my boil I chill the wort down to roughly 75 F then pitch the starter. I ferment at 64-66 in a temp controlled freezer. I noticed that the thermometer on the glass carboy reads +70 F pretty much for the duration of the fermentation. Does this mean that I am actually fermenting much hotter than I realized or is this normal exothermic heat. Thanks for any info.

Cheers,
GHB

 

yes 567890

 

Get a thrmowell dip tube to replace your airlock and you can use that for the thermister on your controller to chill/heat the actual wort.

Morebeer has them as does Brewfittings.

 

depending on what kind of temp controller you have you will probably have to sand the probe slightly to get it to fit in the thermowell. i know i did.

 

I've done away with my freezer these last few batches precisely for the reason you mention. My basement is at 62, and it's giving me 68 when I'm fermenting. As soon as the krausen starts to drop (2 or 3 days), I move it upstairs to room temp(72). It's been very successful so far. My only other advice would be to chill the wort down to 62-64 before you pitch. These 2 changes have helped my beers tremendously.

 

you stopped using a freezer and your brews stayed colder???

 

Thermowell FTW! I'm so happy I got one and have never looked back. Now the temp controller is reading the temp from the center of the wort, not the air in the freezer.

 

Yes. The back of my basement is colder than where the freezer is located. I guess I could have turned down the freezer to 62, but it always just pissed me off to do that. I bought a temp controller for a reason...and then I'd have to bend in there and try to see what the sticker temp was reading...and fidget with the probe taped to the carboy. I'll probably get a thermowell once summer comes around.

 

The Brew Strong episode on fermentation says to tape your temperature controller's probe to the outside of the carboy and then put some insulation over that. They say it will give you very accurate readings of the temperature of the fermentation, not the ambient temp.

 

I do this without the insulation and it works very well. The temp on the controller is the same as the temp on my fermometer

 

That's what I do, but I know the beers have been better using the natural cooling of the basement. It could be something else in my process or it could be in my head, but I swear my fermentations are just more consistent outside of that stupid freezer.

 

I ferment in a wine fridge. I didn't realize until I got a Ranco (as opposed to the Johnson Controls unit I had been using) that my temperature never dropped below 58 degrees due to the maximum cold setting on my wine fridge.

I say this to mention that you might have to McGuyver the wiring on your fermentation fridge if it's not a freezer, but rather a converted wine fridge to bypass the internal thermostat.