Fermenting in tub of water

[jb1677]

I ferment in buckets submerged in a tub of water in my basement. Ambient temperature is 66-68, the tub of water tends to be a few degrees cooler unless I augment with ice. My question is, without a thermowell how can I determine what the actual fermentation temperature is? I understand that the inside of the fermenter can be 5+ degrees higher than ambient but does that how true when ambient is a buffet of water? assuming the water around the fermenter is 65 should I expect inside the fermenter to be any higher or would it not be equalized with the water around it?

 

[rodwha]

What I found was that my beer was 5* warmer then my water. I had used a floating thermometer in the tub thinking the thermal mass of the water would keep the beer similar. Nope.

Beer alone is generally 10* warmer than ambient though.

Get fermometers.

 

[duboman]

I find the stick on adhesive thermometers to be pretty accurate, just be sure they are not below the water line but still registering the wort in the primary.

+/- 2 degrees is my experience when I used a swamp cooler set up


Sent from the Commune

 

[GrogNerd]

I use the stick-on fermometers on the outside of the bucket and have compared it to a probe inside the bucket and the two measured fairly close the entire fermentation.

close enough that I now trust the fermometer

 

[mmlipps]

I find the stick on adhesive thermometers to be pretty accurate, just be sure they are not below the water line but still registering the wort in the primary.

+/- 2 degrees is my experience when I used a swamp cooler set up


Sent from the Commune

Same experience here. I am impressed with the accuracy of the fermometers. Have checked it multiple times. I use a simple swamp cooler method with 2/3 of the carboy submerged and the fermometers is a half inch above the water line.


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[jb1677]

My fermenter is submerged to the point that it almost wants to float - there is very little if any beer above the waterline so the stick on thermometers are no good. I can put my digital against the bucket 6 or 8 inches down and it reads the same as the surrounding water. I guess a thermowell is the only was to know for sure what the temperature is inside the fermenter

 

[J187]

I have used a probe thermometer taped to the side of the bucket with a piece of foam insulation over it. It was pretty much right in line with my fermometer. The times I had the bucket submerged deeper than the fermometer, I'd use the probe.

 

[mmlipps]

Overall. I'd say you are probably good if u maintain the surrounding water in the lower end of the temp range


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[okiedog]

It really helps if you can keep the water level high on your fermenter.

 

[jb1677]

The water level is near the beer level, the fermenter wants to float! I usually circulate ice bottles in the tub to keep the water temp near 60 but then I talked myself into the idea that if the water is 60 that the fermenting wort would be 60 and that's kind of low. With no added ice I stay near 65, which is more reasonable to ferment an ale in so I stopped with the ice - now I am worried if the water is 65 and the beer is +10 then I am at 75. I probably just worry too much, my beer keeps turning out well!!!

For fun I just put my digital in a baggie and submerged it, with the probe right on the bucket right near the bottom and the temp was the same as the surrounding water near the top.

 

[rodwha]

Use ice to keep the water around 60-62* for 4-7 days, and after that stop adding ice bottles. It's likely no more than 5* warmer than the water.