Wednesday, 6 January 2010

Flavour Compound of the Week - Ethyl Ethanoate


I’m trying to alternate between nice and nasty with my beer flavours so this week I am discussing ethyl ethanoate (ethyl acetate to those of you not of a systemic persuasion). Ethyl ethanoate is an ester which you will all no doubt remember from GCSE chemistry as the product of a condensation reaction between an acid and an alcohol. In this case ethanol and ethanoic acid (‘alcohol’ and acetic acid). There are potentially almost 4000 esters in beer. All esters have a fruity flavour. Ethyl ethanoate is used in nail varnish remover so most people associate its aroma with this or nail varnish. Rotten (blue mould on oranges normally reeks of the stuff) or overripe fruit have high levels of ethyl ethanoate.


Ethyl ethanoate is for the most part, produced (biosynthesised) by yeast during fermentation but some is formed from the reaction of the acid and alcohol in the fermenting beer. Two strains of wild yeast are particularly proficient at forming ethyl ethanoate leading to very high levels in Lambics.

Personally I love esters. I think fruit notes on beer are the most appealing of all flavour notes. That said ethyl ethanoate is by no means my favourite.

2 comments:

Ed said...

Speaking of esters, if you don't mind me asking what temperature do you ferment Doom Bar at?

Stuart Howe said...

Not at all Ed. Doom is fermented at 25C. Unusually high but this how the strange Sharp's yeast likes it. If you were trying to replicate Doom without Sharp's yeast I'd use a lower temperature or you'll get yeast unwanted autolysis flavours as most top workers pop at 25C.

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