Fermentation Temperature too high!!!

[Brewberosa]

So we had a chiller malfunction and a beer reached 30 degrees celcius. It is a bog standard 4% Pale Ale. It is still fermenting, and finally at a nice 18 degrees to slow the fermentation but I have no experience with this. The yeast is US 05, and the beer is currently 1018.

Is the beer ruined and what is the best way of nursing the beer back to health?

[MikeyB]

More info?

Where was the fermentation at when this happened? High temps are an especial worry during the initial growth phase, afterwards, not nearly as much. US-05 is pretty forgiving, and a very low ester producer, so if it was later on, you may have a chance. I'd let it finish and let sensory evaluation decide its fate.

[ConversationsFC]

Fermentation too high!

I know that there will be a good chance the beer is ruined from fusel alcohol. Which you would really only know once you drink it (I am sure there are ways to detect it)and it will leave you with a headache. I stumbled on to how to detect this when I had a batch shout up to 80F+ on day two of fermentation and brought it down over the course of the next 12 hours and it finished fine, tasted good. However it leaves this chemically taste on the roof of my mouth and a headache! I didn't but the chemically taste together with fusel alcohol until one day I was tasting a couple brews with a brewer at his brewery and I tasted that chemical, so I asked him about that beer and sure enough the temp spiked on the fermentation. I started researching fusel alcohol and it really only comes from two sources: mainly over heated yeast or seems less often over stressed yeast. i.e. way-over pitched (if there is to many yeast they don't get enough food to do there job) or under pitched. Over heated yeast at the start of fermentation is not good.

I kept some of the bottles from that over heated batch just as a reminder of what happens when it over heats. Plus I have shared with follow brewers and help them know what to look for when tasting beers.

I could be wrong. I would just be careful on serving that until you have a chance to drink a glass and not get the chemically taste and a headache the next day.

Brad

[MikeyB]

Sensory

You can definitely detect fusels. 'Hot,' prickly, especially on the back of the throat and roof of the mouth. Rosy, nail polish remover in some cases, solventy in others. And definitely a worse (fatal in my opinion,) flaw than higher esters- they cause the worst headaches, as mentioned.

[Brewberosa]

The spike was at the beginning of fermentation. The beer will be dry hopped. Fusels also, I believe, give that boozy taste to a beer. Is there anything I can do? double the dry hops? blend it with a good batch?

[ConversationsFC]

Fermentation too high!

The spike was at the beginning of fermentation. The beer will be dry hopped. Fusels also, I believe, give that boozy taste to a beer. Is there anything I can do? double the dry hops? blend it with a good batch?

I would say once the fusel is in there you are not getting rid of it. I would taste it now and see if that chemically / nail polish taste is present. If it is I would say dump it! I know that suck! There is some debate one whether it goes away with time, but as I stated in my first reply I have a couple bottles that are now 18 months old and that taste is still there. I went and opened one just after writing the first time just to see. Yep still there!

Brad

[sjcarter]

agreeing with others in this thread: if you've got fusels, dump the batch. There is a brewery out of California whose beers I still shy away from because one batch of their Imperial Stout was a hot fusel mess.

You have to weigh the direct financial cost of flushing this batch versus the indirect economic impact of putting out a beer you know to be flawed, and the damage that will do to your reputation. The reputation damage is way worse, long term, than the financial hit of dumping one batch of beer that has failed QC.