I recently brewed a Pliny the younger clone, and I'm not sure if I under pitched or if it just fermented too warm, but the beer turned out a little hot. The fusels are slightly detectable in the taste, but very apparent in the aroma. I've read that fusels can be reduced through esterification over time, but my question relates to storage/conditioning temperature. The beer is currently in the keg. Would my best bet (to reduce fusels) be to condition the beer at as close to 32 degrees as possible to retain as much hop character and bitterness as possible, or do I need to age/condition at cellar temps to promote the esterification of the fusels? The beer is only 3 weeks old (from the date I brewed it). Any thoughts or suggestions would be appreciated. Thanks!
According to Professor Beer: “Brewers’ yeast creates relatively large quantities of carbon dioxide and alcohol during fermentation. That is why beer is fizzy and gives you a mild feeling of euphoria. Ethyl alcohol is by far the most abundant alcohol produced by yeast. They do make some other alcohols, too, which are referred to as fusel alcohols. All of these alcohols can be changed into esters inside the yeast cells. The chemical reaction responsible for this conversion is called esterification. The specific alcohol that is esterified determines which ester is produced. If one starts with ethyl alcohol, one ends up with ethyl acetate after the esterification reaction. Similarly, isoamyl alcohol is esterified to the banana-like isoamyl acetate. Easy, right?” http://www.professorbeer.com/articles/esters.html So, it would appear that you need active yeast cells for fusel oils to be converted to esters. If this is the case then cold storage would not be the best condition for this to occur; you want a temperature where the yeast can be active (e.g., room temperature). Cheers!
This is why you let yeast "clean up" the flavor by letting it sit in primary a few days after terminal gravity has been reached, especially for a high gravity brew.
You are going to need more than a few days for fusel oils to be converted to esters; this is a long term process. The best thing to do is to take steps to ensure that excess amounts of fusel oils are not developed in the first place. For example, do not let the fermentation temperatures get too high while fermentation is occuring. Cheers!
That depends on how abundant the fusels are, and (possibly) on the concentrations of certain acids needed for conversion. There are fusels converted to esters during every fermentation. In that sense, it's not necessarily a long term process. If the beer is a fusel bomb, then yes, it's going to take a while, if it can even be fully cleaned up at all.
“The fusels are slightly detectable in the taste, but very apparent in the aroma.” I have no understanding who is the universally accepted authority for declaring a beer to be a “fusel bomb” but the verbiage of “very” may be an indicator in this particular instance!?! Cheers!
The conversation had diverged from the OP's specific circumstances, as you are well aware. Disingenuous much? But let's pretend that it hadn't and play it your way... "The fusels are slightly detectable in the taste," Have you considered seeing an optometrist or perhaps a neurologist for that condition?
Thanks for the suggestions and quick response! I think I'm going to age at room temp for awhile and hit it with another dry hop or two_before cold crashing and kegging.
