Also, in case you missed it, I have a new post up over at All About Beer. It's part of my "quirks of brewing" series. We started things out with parti-gyle brewing, and this week we go to the importance of the ferulic acid rest. What? You've never heard of a ferulic acid rest? Man, do I envy you: your life is about to change.
Once the ferulic acid is in the wort, it can be converted by yeast into a tasty-sounding compound known as 4-vinyl guaiacol, the actual source of the flavor. The yeast must be a special variety known was POF+, meaning “phenolic off-flavor.” It was originally a slur, issued from the perspective of lager breweries who didn’t want any 4-vinyl guaiacol in their beer.Enjoy. And, as always, share the links, and send me your feedback--it's always welcome.
Loved the article in All About Beer about the ferulic acid rest. I don't know why, but the more I read about mash rests, the more I want to know. The science behind it is so cool.
ReplyDeleteThanks! Yeah, it's fascinating chemistry. You need to have the ferulic acid rest to release the ferulic acid, but in order to get the weizen phenols, you have to have a yeast that will convert the ferulic acid into 4-vinyl guaiacol. It's complex chemistry (both bio and inorganic)--and must have surely come about by happy accident originally.
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