Fusel Help Needed

Guys:

I have a bad fusel alcohol problem with an AG batch of Scotch Ale. Probably under-pitched it due to all the freaking' malt. Is there any way of getting the fusel oils out or reducing their strength??? The batch is now in the keggerator and has been for about three weeks. The passage of time doesn't seem to be reducing the presence of the hot/solventy taste.

All thoughts will be appreciated.

John

The main reason for Fusels is high fermenting temp.

More info will get more accurate responses.

I have had it happen to me, and sadly the fusel alcohols won't get re-absorbed over time like acetaldehyde or diacetyl. Having said that, the harshness of the off-flavour (that hot, solvent-like) flavour does recede. I had a brown ale that was fermented to warm and under-pitched that had a lot of fusels in it, and it was undrinkable at one month, and very quaffable at three. But that off-taste never disappeared entirely. Sorry.

I am afraid you are pretty well stuck with what you have. It will mellow a little, but not much, over time.

Underpitching will tend to give you more esters, but that will not give you the fusel alcohols you are reporting. High fermentation temperatures are the primary cause of that.

Packages (vials, smackpacks, whatever) list a range of fermentation temperatures. These are based on the fact that the packages normally contain only about half the recommended pitching rate for a 5 gallon batch of beer. These recommended temperatures are intentionally a bit high so you don't get overly long lag times when you pitch them without a starter.

You should normally ferment at or below the lowest recommended temperature. If you exceed the upper range at all you will begin to get the fusel alcohols.

Another thing about fermentation temperatures a lot of brewers miss is that the fermentation process generates heat, as much as 7-10°F above the ambient temperature in the room. The higher the OG, the greater the temperature rise. Also the higher the temperature at pitching, the greater the temperature rise. Also the fermentation temperature refers to the temperature of the wort, NOT the ambient temperature in the room.

Wayne
Bugeater Brewing Company