Fermentation chamber probe thoughts

[pretzelb]

I have only had my chest freezer fermentation chamber for three 5g batches. I started with putting the probe in a growlers with an inch of water. Then I started reading some threads on another topic and I saw how some people take the White Labs bottles and use them (dry) to enclose the probe. I guess the idea is taking the temp of the air vs. a body of water. Now I'm not sure which to try. Any opinions?

 

[Bordy]

I tape then probe to the carboy covering it with a sock to try and get as close to the carboy temp as possible, works pretty well.

 

[pretzelb]

I tape then probe to the carboy covering it with a sock to try and get as close to the carboy temp as possible, works pretty well.

Funny you say that, all the old posts I was reading mentioned having one probe on the carboy and another in the fridge/freezer. I should have saved the links to those threads - my bad.

 

[rtracer]

I leave the probe hanging in the air from the controller. I have a separate thermometer with the probe taped to the carboy insulated. This lets me know the temp of the beer. I adjust the chamber temp accordingly. During active fermentation, I have the controller set. 4-6* colder than intended beer fermentation temperature.

 

[mongoose33]

This is how I do it--it shows me doing a warmup after fermentation, but the idea is the same whether heating or cooling.

I cut a shallow notch in the foam to cradle the temperature probe, and it's held to the fermentor with a bungee strap.

 

[ame]

I took one of the common "waterproof" DS18B20 sensors and slid about 40 cm of silicone tubing over it. First, I cut off the heatshrink over the joint between the stainless steel tube and the cable, so the joint is covered only with the silicone tubing. The tubing covers the stainless steel by about 15 or 20 mm, leaving the rest uncovered. If you use tubing with less than 6mm internal diameter then it will fit snugly. I drilled a hole in the fermentation vessel lid just smaller than the external diameter of the tubing, so that it forms a snug seal there too.

 

[m1k3]

From most to least accurate:
- thermowell in the beer
- taped to the side and insulated
- in another liquid not beer
- dangling in the air

 

[Sadu]

I drilled a hole in the lid of my fermenter bucket and hang the probe in the beer. Works great and I can forget about the whole argument of ambient temp vs beer temp.

Only downside is that my airlock has pretty much stopped since drilling the lid - I think the grommets around the probe wire are quite thin and the CO2 pressure is pushing out that way. I don't think it has any ill effect on the beer, but I do love a bit of airlock activity.

 

[Saboral]

So not to advocate a specific sponsor, but for 12 dollars and change plus shipping you can get a beautiful thermowell from brewershardware.com I bought three at HomebrewCon 2016 from them and installed in each of my bucket fermenters. Results have been great and they are completely sanitary and able to be easily cleaned of any organic matter.

 

[ame]

Shipping from the US to here is expensive. My solution cost about 50 cents.

 

[Jwin]

Shipping from the US to here is expensive. My solution cost about 50 cents.

Good thermowells on AliExpress.
Your solution will work, until bacteria sets into the area between the tubing and the probe while it is sitting on a shelf between brewdays. If it happens once, a thermowell was cheaper.

 

[ame]

Good thermowells on AliExpress.
Your solution will work, until bacteria sets into the area between the tubing and the probe while it is sitting on a shelf between brewdays. If it happens once, a thermowell was cheaper.

I clean it after use, and there is a tight seal between the silicone tubing and stainless tube of the sensor. It's no worse than trying to keep the seal on the tap at the bottom of the fermenter clean. Plus, I boil it before a new brew. The sensor is ok to +125 °C, the stainless steel is ok, and so is silicone. Or I could just cut a new one every time.

 

[acidrain]

From most to least accurate:
- thermowell in the beer
- taped to the side and insulated
- in another liquid not beer
- dangling in the air

I found that using a thermowell created wild cycling of the air temp to maintain the beer temp. This used the most power, and was a waste of electricity to maintain the beer temp.
To me, the most accurate, consistant, andf efficient way is placing the probe against the side and covering with insulation.
Letting dangle in the air or placing in a small amount of liquid did not control the temp of the beer. Fermenting beer does it's own thing, so you need to monitor and control the beer, not the air.

 

[Jwin]

I found that using a thermowell created wild cycling of the air temp to maintain the beer temp. This used the most power, and was a waste of electricity to maintain the beer temp.
To me, the most accurate, consistant, andf efficient way is placing the probe against the side and covering with insulation.
Letting dangle in the air or placing in a small amount of liquid did not control the temp of the beer. Fermenting beer does it's own thing, so you need to monitor and control the beer, not the air.

This varies depending on fridge vs freezer.
Freezers will get so much colder before the beer temp drops a nominal amount
I'm in the process of working on a dual controller, that will work well in theory.
One relay will run off of beer temp, the other off ambient air temp.
Once the beer gets warm, the fridge will kick on through controller 1. controller 1 will be fed by controller 2 which is tripped my ambient temperature. It will be set to 6-8 degrees lower than fermentation temperature.
Should keep the fridge from overshooting and reduce energy use.
I will probably have to find the sweet spot for the set point for controller 2, but I'm guessing it will be between 12-6 degrees. Will probably need to change that to a smaller differential once primary fermentation is complete.
I have an ink bird itc1000 and itc2000 I'll be trying this with. Will see, but makes sense in my head.

 

[m1k3]

I spray starsan inside the thermowell so that the probe is in contact with liquid that is the same temperature as the fermenting wort.

I would imagine if there was air in the thermowell then it would cause the temp to swing. But with liquid inside of the thermowell I don't have that issue.

 

[bendog15]

I just tape the probe to the side of carboy with a piece of insulation covering probe. Works like a charm.
Probe in the air = ambient temp. Good for ramping up temp at the end of initial fermentation or cold crashing.

 

[Curtis2010]

I made my own thermowell from a dip tube. Easy and cheap.

View attachment 1466940819830.jpg