Stick-on thermometer. Does it measure beer temp, room temp, or combination?

[max384]

As the title says, what does a stick-on thermometer on the side of a fermenter measure during fermentation? The warmth of the fermentation would surely transfer to the outside of the plastic I would think. But, how much so?

I've also noticed in my own brewing that the temperature is warmer during active fermentation, which also tells me that the thermometer is picking up some of the heat from fermentation... Again though, how much. Is it closer to the actual temperature in the room or in the fermenter?

 

[StuckBrauer]

I've heard it should be within 1 or 2 degrees of the temperature inside the fermenter. But someone may tell you otherwise.

 

[glick]

In my experience with mine it measures the temp inside of the carboy

 

[NeoBrew]

It would be easy to test this. Fill the carboy up with water at about your fermentation temp, stick in a thermometer you know is accurate, and see if it matches the temp on the stick on thermometer.

 

[max384]

It would be easy to test this. Fill the carboy up with water at about your fermentation temp, stick in a thermometer you know is accurate, and see if it matches the temp on the stick on thermometer.

LOL. All of my fermenters are now full at the moment. I had thought about waiting and doing this once I emptied one of the fermenters, but I was curious and wanted a more instant answer.

 

[Qhrumphf]

I've checked mine periodically. It's always +/- 1 or 2 degrees of the beer inside in my observations but YMMV. That's with buckets. Haven't tested with a carboy

 

[day_trippr]

I expect the accuracy of stick-on LC thermometer strips are dependent on both the thermal conductivity of the vessel and the temperature differential between what's inside the vessel and the ambient air surrounding it. So they'll more accurately reflect wort temperature on a glass vessel vs a plastic bucket, as well as during small differentials vs large.

On my glass carboys during fermentation they're remarkably accurate when checked against a long stem digital thermometer stuck into the wort, but on the way down to ~34°F for a crash cool, not as accurate until terminal temperature is reached.

I'll also say my temperature controllers always have their probes strapped to vessels with a thick chunk of foam insulation over them, and the LC strips usually correlate very well...

Cheers!

 

[tooladverser]

I am using this Digital Laser Infrared Temperature Thermometer.
I think it is pretty accurate to test the temperature of room or object’s surface.

 

[poislb]

I tested this out a while back, there pretty accurate.

https://www.homebrewtalk.com/f11/ever-wonder-about-those-stick-thermometers-278143/