Fermentation temperatures

[JohnnyD]

Hi all, new to brewing as you all know, but a question, is there a chemical reaction that increases the temperature within the fermentation barrel, I notice that whenever I have a heathy fermentation going, the temperature is always 24C but a vessel next to it will be 21, the same as the room temperature, but I can never get the temperature down to that on a healthy fermentation, it seems to lock at 24C?

JD

[JamesF]

I'm fairly sure that the conversion of sugar into alcohol and CO2 by the yeast releases heat.

James

[JohnnyD]

So when kits say 'for best results' keep the fermentation to 20-21C' do they mean the local air temperature, or the actual temperature of the brew, ie it would need to be in an air temperature of 16-17C to achieve that?

JD

[orlando]

is there a chemical reaction that increases the temperature within the fermentation barrel,

Yes, lookup exothermic reaction. Most brewers do some kind of cooling control, the favourite method is using an old fridge with a tube heater controlled by and STC 1000. Search on here and you will find many examples and explanations. You will also find that after good sanitation practice it is the number 1 tip.