99 Degrees during primary fermenting?

[spaceyaquarius]

I'm at 5 days in the primary fermenter bucket. My indoor/outdoor thermometer says it's 99 Degrees F in the bucket (probe is in the liquid), while the ambient temperature of the house is 68 F. I know fermenting increases the temp, but 30 degrees? Sounds impossible?

Replaced the battery, same reading, sometimes 98 F, the thermometer is brand new, and it is reading the indoor temp correctly (68 F).

Is that even possible? I used two dry yeast packets and stirred them in for one minute. Brewed Austin Homebrew Supply "Texas Blonde" ale. When beer ferments over 80F, it tastes terrible in my experience.

I don't want to open the bucket and put a new thermometer in because I don't want to expose it to oxygen.

Thanks.

 

[cloudybrewer]

HOLY CRAP, BATMAN! I want to know how that's possible, too.

 

[Bostrows128]

There should be a co2 blanket on top the beer so it will protect it from oxygen, some don't believe it but it calms people down. Put a new thermometer in, if not just buy a stick on one from your LHBS for now. 30*
is high but possible.

 

[Morrey]

My guess is that the thermometer's probe is not intended to be submerged. With an ambient temp of 68F indoors, the yeasts exothermic heat reaction can drive the temps up some...but usually this heat adds only around 5 - 8F to ambient during peak fermentation. My guess is your probe is the issue.

There are probes designed to be submerged, but most folks take the probe and tape it to the outside of the fermenter, then put some sort of insulation over the probe. I used a neoprene can hugger taped over the probe as insulation.

 

[mongoose33]

There should be a co2 blanket on top the beer so it will protect it from oxygen, some don't believe it but it calms people down. Put a new thermometer in, if not just buy a stick on one from your LHBS for now. 30*
is high but possible.

Actually, the idea that CO2 forms a blanket is a myth. CO2 and air will mix. The idea that CO2 forms a blanket probably comes from people watching dry ice sublimate and condensed water vapor form a layer. Left to itself, though, CO2 and air will mix.

 

[mongoose33]

Unless.....COLD FUSION!

 

[JohnSand]

It should feel pretty hot to the touch if it's 99, like a warm bath. If it is cooler than your skin, it's under 88.

 

[Jtvann]

CO2 and air will mix when there are convective currants. In an open air environment, gasses will mix. In a closed container, gasses take on the same fluid dynamics as liquids ... they will stratify. Layers are formed specific to density.

 

[day_trippr]

No, no and no.
"Molecular motion". Ever heard of it?

This is why gases mix - even with zero influence...

Cheers!

 

[spaceyaquarius]

I'm at 5 days in the primary fermenter bucket. My indoor/outdoor thermometer says it's 99 Degrees F in the bucket (probe is in the liquid), while the ambient temperature of the house is 68 F. I know fermenting increases the temp, but 30 degrees? Sounds impossible?

Replaced the battery, same reading, sometimes 98 F, the thermometer is brand new, and it is reading the indoor temp correctly (68 F).

Is that even possible? I used two dry yeast packets and stirred them in for one minute. Brewed Austin Homebrew Supply "Texas Blonde" ale. When beer ferments over 80F, it tastes terrible in my experience.

I don't want to open the bucket and put a new thermometer in because I don't want to expose it to oxygen.

Thanks.

Temp now reads 101F. Impossible. Felt the fermenter and it's cold to the touch as the room temp is now 64F. The thermometer must be defective somehow, but reads the indoor temp correctly. The probe is ok for liquids as I have 4 others that work just fine for over 3 years. Got a bad one I think.

 

[Jtvann]

When alcohol influences common sense to think it understands the laws of physics better than .... well the laws of physics.

Dilly dilly good sir

 

[myndflyte]

Time to trash this thermometer.

 

[Bostrows128]

Actually, the idea that CO2 forms a blanket is a myth. CO2 and air will mix. The idea that CO2 forms a blanket probably comes from people watching dry ice sublimate and condensed water vapor form a layer. Left to itself, though, CO2 and air will mix.

that's why I said some don't believe it, people get peace of mind by the concept though.

 

[Morrey]

Temp now reads 101F. Impossible. Felt the fermenter and it's cold to the touch as the room temp is now 64F. The thermometer must be defective somehow, but reads the indoor temp correctly. The probe is ok for liquids as I have 4 others that work just fine for over 3 years. Got a bad one I think.

When I used plastic fermenter pails, I drilled a second hole in the lid in which to fit a stainless steel thermowell extending into the center of the wort. This solves the problem of submerging a probe, plus it makes an airtight seal so no air can get into the fermenter. Don't know how you are getting the probe in under the lid now, but w/o a thermowell, you may have damaged the probe wire snapping the lid on top of it. Also, if the probe is not designed for long term submersion into liquids....anyway, you seem to have a probe issue.

If you are interested, Brewers Hardware sells .375" thermowells in a variety of lengths to accomodate your fermenter size. I bought a pack of .375" rubber grommets at Lowes, then drilled a hole to fit in the grommet. This system worked very well for me and keeps the probe dry while maintaining O2 free integrity.

 

[seatazzz]

Or you can just buy the stick-on fermometers. They're cheap and fairly accurate.

 

[Morrey]

Or you can just buy the stick-on fermometers. They're cheap and fairly accurate.

Very true, indeed. I was using the probe for an Inkbird ATC on a chest freezer, but a stick on works fine for reading in the ball park fermentation temps.