Ok, in my continuous travels of 'not knowing sh$^' I thought diacetyl was formed if the fermentation got too hot, depending on the yeast of course but there was a point 72F-78F where if the fermentation remained over that temp. for x amount of time (or did it just need to once hit those temps?) that diacetly was formed. (wow - long sentence sorry)
So, in 'Brewing Classic Styles' (Zainesheff, Palmer) directions are given to ferment (this is a stout - using Wyeast Irish Ale Yeast) at 65 degrees and 'slowly raise the temperature during the final third of fermentation by 6 degrees to reduce the diacetyl levels in the beer' ...
So I'm confused. I thought they weren't forming at 65, and then raising the temp to 71 if anything would form, and not destroy them? Are they just always there and an intermediate temp like 71 gets rid of them? Pretty weird, cause then if you go too high they reform??
One more thing... what would you consider the last third of fermentation? Hours 36+ ? My typical strong fermentation is 48-72 hours depending upon the wort.
Thanks for any help people!
So, in 'Brewing Classic Styles' (Zainesheff, Palmer) directions are given to ferment (this is a stout - using Wyeast Irish Ale Yeast) at 65 degrees and 'slowly raise the temperature during the final third of fermentation by 6 degrees to reduce the diacetyl levels in the beer' ...
So I'm confused. I thought they weren't forming at 65, and then raising the temp to 71 if anything would form, and not destroy them? Are they just always there and an intermediate temp like 71 gets rid of them? Pretty weird, cause then if you go too high they reform??
One more thing... what would you consider the last third of fermentation? Hours 36+ ? My typical strong fermentation is 48-72 hours depending upon the wort.
Thanks for any help people!