Fermentaion Temp and Ambient Temp

Depending how vigorous fermentation is, it could be up to 10 degrees warmer. So no.

 

Exothermic reactions have their up and down sides. : )

This is why I always recommend a ghetto swamp cooler for new brewers and cheapskates like myself : )

 

I did the swamp cooler thing for the first year I brewed. I got a chest freezer and temp controller after that and haven't looked back. Then again in Texas my house temperature never gets below 76 for much of the year because the A/C already costs too much. A chest freezer was far more economical than cranking down the thermostat. I keep a separate thermometer in a bottle of water in my freezer to gauge the temp offset between the water and the wort when fermenting. I usually see the water running 5-6 degrees cooler when fermentation is in full swing.

 

In a small fermenter such as a 5-gallon carboy the difference between the air temperature and the beer temperature is usually within about 5 ºF. So if you have a yeast strain that produces the best beer when fermentation is held at 70 ºF the surrounding air temperature should be around 65 ºF. You can periodically monitor this by inserting a thermometer into the fermenting beer. - Mr. Wizard / BYO

 

I could be a douche and tell you to google it : ), but in a nutshell: a cooling concept/apparatus that relies on air being drawn over something cool to remove more heat than would have been removed through normal heat transfer to ambient. I hope I'm close to the Wikipedia entry : ) In homebrewing circles, a fan and a wet T-shirt over your fermenter, submerged in an ice/water bath)

 

Occasionally, I measure the internal temperature on the second or third day. It's usually 2F - 4F higher than ambient. Not sure who started the "could be as high as 10F hotter than ambient" line. I think it was Palmer. I have never measured anything near that with beers below 8%. Bigger beers may get hotter, but I don't brew them.

 

A little known secret organization similar to Free Masons and the Illuminati (Palmer, no doubt) : )

 

I think it was the Temperature Controller Consortium that originally spread that disinformation.

 

*passes out tinfoil hats*

 

I don't think I have ever had a temp more than 5F above ambient and that was with a raging fermentation, but that was probably a 1055ish beer. With that said, a large cooler or a plastic tote and a water bath will go a long way in controlling fermentation temps.