Our moose drool type ale has been fermenting. It is time to rack it but it has been on at brewer heating pad and we just realized it is 86 degrees F. It may have been that warm for 1-2 weeks. A dark towel has been wrapped around it for sun protection but would keep the heat in. Have we ruined it?
You'll likely notice quite a few off-flavors that were not intended to be in the style that you brewed.– brendo234Mar 2, 2017 at 20:51
Yes, fermenting at that high a temp can cause off flavors. The most prevalent and common one will be fusel alchols. Those can give your beer an almost "nail polish remover" flavor and can generate huge headaches after drinking. IN addition, depending ion the yeast you used, you can get a great increase in fruity esters, which may throw off the flavor profile of the beer. In general, you'll get the best quality by maintaining temps in the 65-68F range.