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CAMR*L*, Bayerischer Anstich

Posted by Uncle Jimbo on 2010-08-25 07:11:50

Yeast do not usually produce diacetyl directly. Instead they produce acetolactate. Yeast cannot metabolize acetolactate. However, in the presence of oxygen, acetolactate will spontaneously oxidize (and decarboxylate) to give diacetyl. Brewer's yeast can metabolize diacetyl. This is why brewers allow time for the yeast to digest any diacetyl (and allow time for any acetolactate to be changed to diacetyl). http://www.google.com/imgres? imgurl=http://www.biokemi.org/assets/499/brewing_7.jpg&imgrefurl=http:// www.biokemi.org/biozoom/issues/522/articles/2368&h=326&w=500&sz=19& tbnid=_wzHlKcPRa3bOM:&tbnh=85&tbnw=130&prev=/images%3Fq%3Dacetola ctate&zoom=1&usg=__NU_xUmvBdjb-_N- FrkbzJPeUNQQ=&sa=X&ei=bSV1TMfsBMP-8AaO4OWOBw&ved=0CDAQ9QEwBg

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Diacetyl by Uncle Jimbo on  2010-08-25 07:27:54