Beer Forum

What is the best temperature to ferment ales at? I put my carboys in the basement and it stays anywhere between 72-74 degrees. Is that too warm?

Most ale yeasts should be able to ferment just fine at those temps. I would recommend trying to lower the temp a bit if you can. I typically ferment ales around 60-65F.
Most belgian yeasts like the warmer temps. even as high as 90-95F.

But the real answer can be provided with the end results. How does the beer taste when finished? Are there alot of esters and diacetyls? If there are, maybe dropping the ferement temp is something you might want to try.

IMHO, anything above 74°F, & you're asking for trouble. Keep it as cool as possible. Build a swamp cooler if you need to.

Also keep in mind that you are going to have a 6 to 8deg raise in temp during primary fermentation. The yeast generate a lot of heat when they are working. Setting the carboy on the floor down there may keep it cooler than the air temp.

Travis

Another option is to check the website for the manufacturer of the yeast you are using. Both White Labs and Wyeast list optimal fermentation temperatures for every strain of yeast they produce on their respective websites. This is the data I tend to go with when fermenting.

Ken Powers wrote:Another option is to check the website for the manufacturer of the yeast you are using. Both White Labs and Wyeast list optimal fermentation temperatures for every strain of yeast they produce on their respective websites. This is the data I tend to go with when fermenting.

These "optimal" temps are based on the fact that, without a starter, you are underpitching. To compensate for that, they give higher than optimal temperatures so you will get a faster start even though you will get better flavor by using a starter and fermenting about 5° lower that the bottom of the "optimal" range. If they gave you the proper amount of yeast to use without a starter and recommended the actual optimal range, they would have to charge you quite a bit more than they gouge you for now. < rant mode now off>

In my experience, the danger of fermenting with ale yeast above 70F is excess diacetyl and fruity esters, if too much higher than 75F you run the risk of increased bacteria production.

The bottom line: it depends a lot on the yeast strain your using, consult the temperature guidance given by the manufacturer. If you go any higher than that, you run a higher risk of the yeast creating off-flavors.

I recently fermented an ESB with the wyeast 1968 London ESB ale yeast at 78F slowly dropping to about 71F within the first week after transferring to the secondary. The published yeast profile from wyeast recommends fermenting at 64-72F. The yeast profile in this finished beer is very fruity and tasty, but too much diacetyl for me.. I would have been better off controlling the temp down so that fermtnation started in the low 70s at the most.

For me 65-68 works well for most ales. Belgians I ferment at about 70 - 72. If all else fails I like to err on the cool side as long as it's not much below 62 or so. If I want a larger like finish I may get down to 60 and plan on a 2 week primary.