Fermentation Temp. Monitoring Tools

I recently made my first batch and kept it around 75 F during fermentation using a tub full of water. To monitor my temp, I used a digital thermometer with a 6 ft. probe stuck in the tub of water. I would have liked to view the min/max temps. that it hit each day just to get an idea of the fluctuations. What does everyone use? Something along these lines: Thermometers - NIST Traceable® Thermometer with Time/Date Max/Min Memory Control Company 4105

Thanks!

 

I haven't finished my temp monitoring outfit yet. My idea was to hook it up to an old laptop and track the temp every 15 mins or so on a chart. Some others have done something similar with more expensive equipment, and some have done it with cheap equipment. Most people are satisfied to take a look at their thermometer once in a while.

That looks like it would work ok, but how accurate is it, and how accurate do you need it to be? I wanted mine to be +- .5 degrees F so that I coudl use it in the mash as well.

 

I bought a $9 digital thermometer at my local Lowe's that has a submersible probe and will store a min/max temperature of the probe (outdoor) and at the thermometer (indoor). It does not have time/date though. The min/max values can be individually reset any time you would like. I do not see it on their website, so it may just be a local thing. Let me know if you want more information on it and I can look when I get home.

I am just using it to measure the air temperature inside my SOFC, but you could use it to measure the water temp if you would like since the probe can go underwater.

I don't have any experience with swamp coolers, but will the water temperature accurately portray the fermentation temperature?

 

No, in my experience. The fermenter will be 4-6 degrees warmer at the peak of fermentation. I used a stick-on thermometer on the fermenter and added ice to the water bath to hold the fermenter at the desired temp.

 

The contact method (tub of water) is going to get you more accurate thermal transfer, so a tub of 75F water is most likely 75F in the carboy/bucket. The chilled air method works, but your wort's temperature will be 4-8 degrees warmer.

That said, what is the recommended thermal range for your yeast? very few yeasts like 75F, 60-70 is much more common. Try to drop some ice packs in that tub of water daily.

 

Test this with a stick-on thermometer on the fermenter and a thermometer in the water. I have found that the fermenter will be warmer than the water temperature at the peak of fermentation. YMMV ...