battling temp. change...

[andyveedub]

I have a 16cu ft chest freezer that I have a digital temp control on, in it I have 2 carboys a 6 and a 6.5 gallon. I brewed a batch last sunday and another one on tuesday afternoon. I have my temp controller is set for 68 degrees. I tape the temp probe to the side of the carboy to be as accurate as possible. My 6.5 gallon, with the beer I brewed sunday is at 65 degrees, and the 6 gallon, which is right next to it with the beer I brewed on tuesday, is at 68ish. Whats with the 3 temp difference? How can I get them to stay the same? Is the problem that the tuesday batch is more actively fermenting causing the difference in temp? also will the lower temp of the other carboy effect the outcome of my beer negatively? How can I get them to stay at 68?

 

[indigi]

You can't get it to stay the same because you're only monitoring the one bucket. As long as that bucket is below 68*, the freezer won't turn on, so if the other beer is slightly warmer, it'll keep getting warmer because the freezer's not running. Different beers with different yeasts ferment at different rates, so one might be putting out more metabolic heat than the other. Put the buckets as close together as possible, and put the thermometer between them. That's about as good as it's going to get.