Questions about ambient temp, fermentor temp and swamp cooler

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slcdawg

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Another noob question. :) I understand the fermentor temperature will be 5-10 degrees F higher than the air temp. For my first batch, the air temp was 68 but the thermometer on the fermentor was showing 76-78.

I gather you want the fermentor temp (not the air temp) to be within the range specified on the yeast? And that I need to cool the fermentor down for the next batch.

On this forum, I've read numerous tips to create your own swamp cooler by placing your fermentor in a tub, filled with water to the beer line, and ice packets to lower the fermentation temp. For this setup, how do you measure the temp of the fermentor? It would seem the thermometer strip on the outside of the fermentor would measure the temp of the ice bath and the fermentor and not be accurate. Do you open your primary up and dip a sanitized thermometer in the wort (maybe through the airlock hole)? Or, just go off the thermometer strip on the outside of the fermentor?

Thanks! :mug:
 
From the fermometer instructions: “The Fermometer™, like all LCD thermometers, is water resistant, not water proof. While it can easily be rinsed or washed with traditional cleaning and sanitizing solutions, it should not to be continuously exposed to these or other solutions for extended time periods.” So I put the fermometer at about the 4-1/2 gallon level and fill the water to just under it. A towel draped over the fermenter with the ends in the water helps it cool by evaporation (“swamp cooler”).
 
I use a floating thermometer in the cooler water and double check the carboy with a laser digital thermo. The water bath is pretty easy to maintain, especially if you have everything at the desired temp going in. Another way to do it would be to use a thermowell and a temp probe, that way you're getting the exact temp of the center of the fermenting wort, but either way will work just fine.
 
NASA has a service where they will read the temperature anywhere on the globe, to an accuracy of .0002 degrees. The only trick is you have to have your jug outside when the satellite is going over. Plus, it costs $110,000 per, but for good beer it's worth it.


Like ncbrewer said: swamp cooler, thermo strip, towel (or t-shirt). Unless you're turning pro, there's no need to overthink it.

No worries!
 
I put the fermometer at about the 4-1/2 gallon level and fill the water to just under it. A towel draped over the fermenter with the ends in the water helps it cool by evaporation (“swamp cooler”).

Ah, now it makes sense. Thanks for the info!
 
I also only fill my swamp cooler part way. Only 1/2 of my beer is exposed to water- and the fermometer is way above that not in water- and my temperature has been a solid 60F for 5 days. One day it was really hot and moved to 62F - thought I was going to have a breakdown. Temps got cooler over the next day or few days- so going with small frozen bottles instead of 2 liters- till I need to amp up the chill
 
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