What temperatures can brewer's yeast survive at?

Question

I brew my own beer, but can not keep my house cold enough for the recommended yeast fermentation levels. At what temperatures do I risk killing the yeast? My house typically sits at around 80 degrees but can get up to ninety degrees Fahrenheit. Should the yeast be able to survive at these temperatures?

Answer 1

Bakers yeast will die at 120 for sure. Brewers yeast temps are more about taste than dying. Fermenting speeds ie. temps affect taste big-time. The Germans ferment cold and drink their beer cold. The British ferment their beer room temp and drink it room temp. As long as you are getting a proper fermentation it's only taste you will be dealing with.
Do you have access to a basement? That would help.

Answer 2

Most brewing yeasts will survive up to about 125F, however the above posters are right- you need to ferment at the right temp. in order to get the right taste profile for the style/yeast you're brewing. 80-90 is generally way too high for most styles. Depending on the yeast strain, with those temps you are looking at producing the following negative characterstics-

-Fusel alcohols - that "hot" alcohol taste that you get from some whiskeys. Also a major contributor to headaches/hangovers. Nasty stuff.
-Excessive fruity esters - you want some ester profile in most beers, but you will end up with some funky tasting brew from the level you'll get at 80+F.
-A whole host of other off flavors, depending on the yeast strain, including metallic, rubbery, astringent, etc.

My suggestion would be to either reduce your temps or brew some styles that can stand up to the heat. A fridge with a temp control is one option (look used), a cool water bath is another. Some styles to look at would be Saisons, Belgian strong ales such as tripels, dubbels, etc., possibly wits. Honestly, though, you should find a way to control those temps, it's the single most mportant factor in your fermentation, which is the single most important step in brewing.

Answer 3

THE YEAST WILL SURVIVE AND GROW FASTER AT THE WARMER TEMP. BUT THIS WILL AFFECT TASTE. bEER IS USUALLY BREWED COLD FOR TASTE AND THE YEAST IS ABLE TO WORK AT LOWER TEMPS. i HAVE KNOWN SEVERAL HOME BREWERS WHO HAVE REFRIGERATORS JUST FOR THE BEER. fOR ABOUT $100 ONE BOUGHT A LITTLE ONE AT wAL-MART TO BREW 5 GAL. AT A TIME. i KNOW SEVERAL WHO BOUGHT USED ONES AND USUALLY HAVE TWO OR MORE BATCHES GOING.
iF THIS IS NOT PRACTICAL FOR YOU TRY ALE INSTEAD. tHE YEAST PREFERS WARMER TEMPS. SORRY ABOUT THE CAP LOCK.