Fermentation heat

[Poppajim]

I recently built a heat only ferm chamber. My basement gets chilly in the winter. I've read that fermentation can cause excess heat, therefore I set the temp to about 65. I haven't seen an increase in temp and it's been 3 days. I'm still using mr beer LBKs. If anyone is familiar with these, they don't have a conventional airlock, but rather notches in the top where the cap screws on. I'm wondering if this setup is allowing heat to escape more easily than if I was using a real airlock, which is why I'm not getting a change in temperature. I just checked it and it did go up 2 degrees. That could be it.

 

[RM-MN]

When you start your fermentation cool the yeast work more slowly so they release the heat over a longer period which then allows the heat to dissipate to the surrounding air and you won't get much rise in temperature. As the temperature goes up, the yeast work faster, releasing heat faster which takes time to dissipate but while the temperature is up, the yeast work faster yet, releasing more heat, much like a runaway nuclear reactor. I usually start my ferment at about 62 degrees ambient and find that the temperature only reaches about 64 degrees at the peak. With that low starting temperature the lag time also goes up since it takes longer for the yeast to multiply. That might be one of the reasons you didn't see a temperature rise for the 3 days. I expect to see activity in 30 to 36 hours with my beers.

 

[daksin]

The larger your batch, the more heat you'll generate. At 2 gallons, the ferment probably isn't generating so much heat that would overcome the ambient temp, especially because a smaller batch has a higher Surface area to volume ratio from which to radiate the heat away. 2 degrees is all the temp rise you may see, or you may see none, depending on the beer, the yeast, the weather etc.

 

[Poppajim]

Thanks to both of you. Very helpful in planning ahead. Happy Brewing!