Can you get rid of fusels?

General Homebrew Discussion
1

Apparently, I let my last batch of Oatmeal Stout ferment too warm. I kegged it and started carbonating it on 3/27/11; on 4/3/11 I pulled a sample and it had a sharp alcohol/solvent finish. I figured it was too young and let it sit in the fridge (40F) for a few more weeks. I pulled a sample off last night, 4/27/11, and it still has the sharp alcohol/solvent finish.

From everything I have read, I think this is fusels; and they are formed from fermenting too warm, so I must  have let it ferment too warm.

Recipe:
10 lb 2-row Pale Malt
0.5 lb Special B
0.5 lb Chocolate Malt
0.25 lb Roasted Barley
0.5 lb Flaked Oats
1 oz Cascade 90 min
1 oz Cascade 60 min
1 oz Cascade 30 min
1 oz Cascade 0 min
Irish Moss
Wyeast 1084 Irish Ale (yeast cake from an Irish Red)

Single Infusion Batch Sparge with equal runnings.
90 min Boil

Chilled the wort to 59/60 degrees before racking onto the yeast cake.

Put bucket into the Fermentation fridge with an ambient temp set to 64F for 2 weeks.

I was busy at work so I didn’t keep a very good eye on this batch, just made sure the fermentation started then ignored it until ready to keg it. I was doing some work on my house in the same area and it is possible that the plug for the fridge got jiggled loose, but I don’t really recall.

Anyway, all of that to get to the question in the subject line.
Now that I have the fusels, can I get rid of them? Will it age out?

Any suggestions and comments are appreciated!
Thanks!
Dano

2

I read a paper by Dr. Bill Pengelly, former head brewer at Deschutes, about how fusels can eventually age out into esters.  So hang on to the beer and hope for the best!

3

i have certainly noticed a reduction in the hot solventy flavour in some beers I have fermented to warm after a few months. and I have noticed with a belgian I brewed that gave be a headache when I first sampled that after a couple of months that stopped happening. I bottle continditioned those beers though so it is possible that the yeast in the bottle had something to do with it.

4

I believe this is why people say you HAVE to age big beers.

Time will diminish the hot character.

Obviously it’s best to not get them in the first place.

5

My experience is that if there is a significant amount, it won’t all age out.

6

From personal experience I have found they will diminish, but not disappear.  I brewed a Belgian Golden a few years ago that had some fusels.  After months of aging - about 4-6, they were less, but still there.

7

There are several perceptions for fusel alcohols: aroma, taste, and splitting headache.  I concur that the first 2 can diminish or dissappear.  What about the third aspect?

8

Just guessing, but I think if the fusels are reduced enough to affect aroma and flavor that the headache effect would be reduced also.

9

I have seen a heavily fusel big beers completely clear, but it took years,  the same thing with meads.

10

Do you think the oxidative effect over time ties up or reduces the fusel alcohols?

Here’s an ultimate beer geek study on the formation of fusel alcohol throught the Ehrlich Pathway.  :)

edit: forgot to add the link.

11

I do not know the mechanism.

I’d rather avoid the problem in the first place and brew a deceptively strong beer.

12

+1 to that!  good temp control & general brewing techniques go a long way to avoiding fusels.

I’m not too up on the mechanisms either, but I think that both yeast and oxidation play a part in reducing fusels over time. The yeast help break the fusels down into esters. Oxidation plays it’s part as well, however oxidized fusels contribute to sherry and cardboard flavors.

So best to avoid or limit them up front. But if you’ve got a hot, fuselly beer then aging my help improve it. Be patient. Certainly don’t dump it, give it time & see what happens.

13

+1

I’ve had a few beers over time that started out pretty bad and over time, as they aged, turned out to be pretty darn good beers.

14

I brewed an imperial stout that got into the mid 80’s for a day.  After 2 weeks in primary it was at FG but tasted like kerosene.  2 more weeks in primary and it was as smooth as silk.

15

Oxidize a  primary alcohol, it becomes an aldehyde.  Secondary alcohols become ketones.  They can also combine with organic acids to form esters.

I have a IIPA that was 1.100 OG and came out really hot at first.  It wasn’t terribly fruity though, so I guess theres a qualitative difference in fusels.  It was pretty tasty after a year.  I just found five bottles on a shelf, its over two years old now.  I’ll chill one and give it a try just for you guys.

16

You’re all heart.  :-*

17

There is a little blurb towards the end of Kaiser’s Doppelbock recipe that says a similar thing that tomsawyer mentioned.  It’s a chemical reaction with the higher alcohols in an acid environment.  It takes a while to happen:

[quote]After lagering rack the beer to a serving keg or bottle and age at cellar temperatures ( 10 C / 50 F) for another 2-3 months. During that time most of the dark fruit notes will be formed by reactions between the alcohols (especially the higher alcohols) and acids in the beer. Some oxidation processes contribute to that as well. Since it is a chemical process, it works better at higher temperatures. Hence the suggestion to lager only for 2-3 months and then take it off the yeast completely and age for another 2-3 months
[/quote]

18

Most of us seem to store at cellars temps for long periods of time. I’ve often wondered what the optimum temperature really is. Are you better off in the 60 F range or all the way down to just freezing, as in lagering? It would be interesting to take several bottles of a less than desirable beer and store them at various temperatures and compare after a few weeks. Which ages quicker?

19

it’s a balance thing. The higher the temp the faster the aging occurs. at low temps it will change much more slowly but will last longer before going over the edge. Higher temps will age it faster but it will go over the edge sooner

20

Time + heat + O2 + fatty acids degrades higher alcohols into the equivalent esters/solventy esters. To the extent that esters aren’t as serious hangover fuel as higher alcohols their headache-inducing power will diminish as well.