Thermowell?

[dmaxweb]

I use these for fermenters.

I mostly brew ales and occasionally lagers. For the lagers, I have a refrigerator controlled by a Johnson A419. In the past, I have taped the probe to the outside of the fermenter insulated with several layers of bubble wrap. Would a thermowell through the lid with the sensor centered in the wort be a better alternative?

 

[McMullan]

I prefer to use thermowells so the probe measures wort temperature directly, but if I haven't got one available I'll use a little foam insulation taped to the outside wall of an FV. It works either way, IME. Even dangling the probe in the fridge works, if you assume the fermenting wort is a few ℃ higher than ambient during active fermentation. Dead easy to fit a thermowell, though, and I'd say go for it.

 

[RM-MN]

Of course a thermowell would be a better alternative. One member of a different forum I sometimes post on did an experiment with his fermenter and discoverer that the thermowell reading was 1/2 degree lower than that of a thermometer taped to the outside and insulated.

Is 1/2 degree critical to your beer?

 

[dmaxweb]

Was that a plastic fermenter?

 

[hotbeer]

I didn't do a side by side comparison, but I did note that the temperature profiles and actual temperatures reached seemed pretty much the same between the RaptPill I just started using several batches ago and the batches prior done with a probe taped to the side with a 4" x 5" x 1/4" piece of foam. At the time mine were glass FVs and a thin walled plastic FV (a 3 gallon FastFerment conical).

A thicker walled FV might give more of a difference in the temp readings.

If I was actively controlling the temp of the beer with a glycol chiller or such, I probably would want the thermowell, Rapt Pill, Tilt or something that will give a more immediate response to temp changes. There probably is a little lag of time between the beer changing temp and that new temp conducting through the FV material to the temp probe on the outside. But maybe not much to really be a bother.

 

[WilliammLesly]

I also use them for fermenters. They make great ales!

 

[bruce_the_loon]

I've found with a thermowell my compressor cycles less frequently, staying off longer, but running for a longer as well. The thermal stability of the wort deep inside the fermenter is bigger than against the surface of the fermenter. So much the same cooling happening, but less frequent on/off switching.

 

[dmaxweb]

I also use them for fermenters. They make great ales!

I've used them for years. I put in rotating racking arms. I can pressure transfer all of the beer off the yeast cake. Add a quart of distilled water, swirl, and pressure harvest all of the yeast cake. They are also perfect size for storing full sacks of grain.