Fermentation Temperature

[the_mad_zymurgist]

Just a quick hypothetical question to further my education.

Many yeasts will ferment at higher ranges than their optimum, BUT:
what is the result of fermenting at higher temps? For instance, if you pitch an ale yeast at 78-82 degrees, and it starts fermenting aggressively (thereby producing some internal heat, and not allowing the wort to further cool down), what is the bad part of this? I’m assuming off-flavor, but some of you can explain this to me as though it’s a 200 level organic chemistry class, and that’s sort of what I’m looking for.

Thanks, guys,

[s_scoggin]

I dont have 200 level organic chem but…

Most yeast will even ferment at 90. But its not optimum for good beer. The yeast start producing unpleasant biproducts at higher temps. Higher alchohols called fusel alcohols like phenols. The yeast will also produce lots of esters (fruity characteristics) that can be unpleasant at high levels. there are others, but like i said, im no microbiologist or a chemist

[wallybeer]

I highly recommend this book " Yeast: the practical guide to beer fermentation" by Chris White and Jamil Zainasheff. Chris White has a doctorate in biochemistry.

[rookie_l_a]

[quote=“S.Scoggin”]I dont have 200 level organic chem but…

Most yeast will even ferment at 90. But its not optimum for good beer. The yeast start producing unpleasant biproducts at higher temps. Higher alchohols called fusel alcohols like phenols. The yeast will also produce lots of esters (fruity characteristics) that can be unpleasant at high levels. there are others, but like i said, im no microbiologist or a chemist[/quote]

Do you play one on T V?

[the_mad_zymurgist]

“I dont have 200 level organic chem but…”

No, this is good. Telling me that yeast produces more than one type of alcohol, depending on fermenting temperature, is a good start.

" Yeast: the practical guide to beer fermentation"
I appreciate the recommendation, I will someday compile all the books I want to add to my library.

Thanks again, guys!

[s_scoggin]

[quote=“Rookie L A”]
Do you play one on T V? [/quote]

hahah, i probably could with all this recycled beer knowledge stuck in my brain. currently attending the three month course at brewlab in the UK, and learning a lot