Fatty Acid Esters

[bleitdm]

I was curious about purposely developing fatty acid esters in a beer. I am looking to get the apple, anise, and floral aromas these esters provide to really come through. I have been doing some research and found the following articles:

http://www.pubmedcentral.nih.gov/articlerender.fcgi?artid=2223249
http://74.125.95.132/search?q=cache:m_V04MRomFwJ:www.beertown.org/events/cbc/seminars/Roger_Mussche2.doc+ethyl+caprylate+producing+bacte ria&cd=15&hl=en&ct=clnk&gl=us&client=firefox-a
and an abstract about yeast heat shocking:
http://www.sciencedirect.com/science?_ob=ArticleURL&_udi=B6T8G-3RXYX5M-D&_user=10&_rdoc=1&_fmt=&_orig=search&_sort=d&view=c&_acct=C000050221&_version=1&_urlVersion=0&_userid=10&md5=b9081748c53fc9809adf106ec4fccfc5

They make several suggestions about these esters. Right now I am thinking about not aerating the wort, aerating towards the end of fermentation to try to develop some more fatty acids, ramp up the temperature for a day or two after aeration, and then crashing it. Also brewing at a higher gravity and dilute later on... Any thoughts on this? I know its strange, but I'm doing a very small test batch so I'm not worried about screwing up.

The main question I have is yeast strain selection. Has anyone had this 'off flavor' develop to make the strong apple flavor? Are ester forming yeast (as a weinstephan) the best way to get these esters also? I would think they would really produce the banana ester but i don't know.

Thanks,

Dave

[South County]

Under aerating/pitching particularly with (German/munich) lager yeast strains tends to really produce the green apple (acetaldehyde) aroma/flavor and takes much longer for the beer to mature, in great excess the beer often is not fully fermented and lacks any clean discernible flavors. Acetaldehyde has also been known (in high quantities) to cause severe hangovers. Personally I would stick away from this since, unlike banana/phenol/clove flavors derived from wheat strains, acetaldehyde is usually avoided. I would be worried about long term stability in the beer and overall beer quality. The way to accomplish what your shooting for is in your grain/ingredient bill. Try using fresh fruits/extracts/wheat/rice in test batches, many breweries get interesting hints of fruits from grain/yeast combinations.

[rudge75]

I recall a flavour of raw fish from a beer that had sat on the shelf too long.

I was at school then and when I asked Steve Parkes (ABG) what that might be from he replied with oxidized fatty acids.

Nothing is impossible, but you'd have to have a hell of a qc program to ensure the beer and packaging was meeting your targets every single time.