Where to put temp control probe?

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blk94f150

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I have a Ranco temp controller and I've just been taping it to the side of the fermentation vessel so that it tries to keep the beer at exactly the temp I'm looking for. My concern is that it might make the freezer get too cold and stall out the fermentation.

For example, I just pitched Wyeast 1084 Irish Ale yeast as 70F and I'm going to let it start fermenting and then drop it to around 62-64 for a clean Irish Red. However I'd think that the freezer would cool much faster than the beer and it might get to be below freezing in the freezer before the beer gets to my desired temp. Then it would continue to get colder and stall out the process.

Any thoughts?

Mike
 
Currently I am taping my probe to the fermenter with a little insulation on the outside. I think it's important to try to measure the temp of the liquid, not the ambient air. My question is how much off is temp when taped to the vessel?
 
if you have any room in freezer, i would put another glass or gallon jug full of water and submerge the probe if possible. that way if you set it to 60, the freezer will only run until the sensor reads 60 and then it will kick off. thats how my keezer is set up.
 
you need a thermowell in your stopper, and that way the probe actually sits down in your fermenting liquid, and you actually measure the temp of your product, and not the air around it.

Dan
 
How does the thermowell work with a blow-off hose? Does it get in the way?

Conehead
 
IMO, thermowell = sanitation risk. I have a homemade temp controller and I just tape the probe to the carboy. No insulation. It might cycle a bit at first, but I've tested mine by keeping a floating thermometer in a carboy full of water and it's dead nuts on. If you don't believe me, you can listen to the Brewstrong podcast regarding temperature control on the The Brewing Network. Jamil does the same thing, and he reports that the glass of the carboy is almost exactly the same temp as the beer.
 
With the probe taped to the outside of the carboy, the freezer will shut off earlier than if you had the probe in the wort. This will tend to balance out the slight over-shoot that is typical of a freezer. The thermal mass of the wort is high enough to damp out the variations.
 
IMO, thermowell = sanitation risk. I have a homemade temp controller and I just tape the probe to the carboy. No insulation. It might cycle a bit at first, but I've tested mine by keeping a floating thermometer in a carboy full of water and it's dead nuts on. If you don't believe me, you can listen to the Brewstrong podcast regarding temperature control on the The Brewing Network. Jamil does the same thing, and he reports that the glass of the carboy is almost exactly the same temp as the beer.

I just listened to the same podcast and agree with you. Putting a glass of water with the probe in it doesn't accurately measure the temperature of the ferment because there is heat that is generated by the yeast which the glass of water doesn't have. So taping it to the side of the carboy with a little insulation covering it will give you a very accurate reading of the fermenting temp.
 
A lot of good points here.

The attachment to the side with insulation is a good non-intrusive compromise.

My solution is similar. I wrap the carboy with one of these sports injury gel packs. The large contact area and thermal mass of the gel pack allow it to track the temperature of the carboy very closely. I then insert the probe between the gel pack and carboy. The probe is then surrounded by material tracking the wort temp.

Gel Pack.jpg
 
I modded my conical to accept an RTD probe. I use it to monitor the temp of the beer during the ferment. However, I control off another RTD that is in a large test tube of water. Know the beer temp, and have vary small temp fluctuations. Best of both worlds IMO.
 
A lot of good points here.

The attachment to the side with insulation is a good non-intrusive compromise.

My solution is similar. I wrap the carboy with one of these sports injury gel packs. The large contact area and thermal mass of the gel pack allow it to track the temperature of the carboy very closely. I then insert the probe between the gel pack and carboy. The probe is then surrounded by material tracking the wort temp.

I like this, that's an awesome idea!
 
Waking up this thread.

i was an idiot and just had my probe sticking out into the air near the top of the keezer. I kept a thermometer sitting on my fermenter and one at the bottom. The one at the top stayed pretty consistant with the temp that controller was set at. The one on the bottom was always about 10 degrees cooler... Heat rises... Doh! best to place probe right on the middle of the fermenter. Lesson learned. Hopefully someone else will learn from my mistake.
 
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