Author Topic: Effect of oxygenation on alcohol perception in high gravity beers  (Read 546 times)

Offline mabrungard

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We have had discussions on fusel alcohols and on oxygenation.  One thread mentioned that excessive oxygenation may cause excessive yeast growth and promote fusel alcohol production.  I'm not sure the thread confirmed that finding, but my question is slightly different.  

I have had beers that report 7 to 9 percent alcohol that presented low perception of alcohol in the beer.  I have also had beers with similar alcohol percentage that present high perception of alcohol.  The high perceptions may not have been fusel in nature (hot).   A local brewery has crafted beers that had little alcohol perception in the past, but now seems to create beers that smack me in the face with alcohol and they are similar strength beers.  

Would excessive oxygenation promote the increased perception of the alcohols in a beer even if those alcohols might not be fusel in nature?  We know that under-oxygenation promotes ester formation and potentially poor or incomplete fermentation, but I have not heard a lot about over-oxygenation effects.
  
Martin B
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Offline bonjour

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Re: Effect of oxygenation on alcohol perception in high gravity beers
« Reply #1 on: May 02, 2011, 10:51:05 AM »
Interesting observation.

My big beers offer a low presentation of the amount of alcohol present, to the point getting dinged in competition for that fact, it's tough when you have a 12-13% beer that doesn't have enough alcohol for style.

I've put it to a low ale temp ferment, but over aerating could also contribute. 


Fred Bonjour
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Everything under 1.100 is a 'session' beer ;)

Offline narcout

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Re: Effect of oxygenation on alcohol perception in high gravity beers
« Reply #2 on: May 02, 2011, 01:45:44 PM »
One of these articles might have some good information:

http://www.mbaa.com/techquarterly/abstracts/1999/tq99ab22.htm

http://www.mbaa.com/techquarterly/abstracts/1975/tq75ab03.htm

http://www.mbaa.com/techquarterly/abstracts/2000/tq00ab12.htm

http://www.mbaa.com/techquarterly/abstracts/2003/1014-01.htm

The last one is about preoxygenating yeast so it's not exactly on target, but it contains the following excerpt: "Formation of esters and higher alcohols was noticeably higher in beers successfully brewed with preoxygenated yeast when compared with that in beers brewed with untreated yeast."

If you google the titles or authors, you can sometimes find free copies online. I've also heard that if email the authors, they will sometimes send you a free copy.
« Last Edit: May 02, 2011, 01:50:02 PM by narcout »

Offline tom

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Re: Effect of oxygenation on alcohol perception in high gravity beers
« Reply #3 on: May 02, 2011, 01:54:17 PM »
Same yeasts?
I really like White Labs 007 for big beers.  Very clean.
Brew on