I'm familiar with diacetyl rests for lagers, but have never done a diacetyl rest (per se) with an ale yeast. I'm making a brown ale with WLP002, and plan to do a diacetyl rest, to avoid the diacetyl that 002 sometimes produces. My question is on the timing... WLP002 is so flocculent, I'm thinking I should probably bump the temperature well before active attenuation is done. If anyone has done a true diacetyl rest with WLP002, please speak up and let me know how you approached it, and how it turned out. TIA!
Well, I do not know if this qualifies as a diacetyl rest, but I normally ferment at desired temperature then let it rise on its own to about 70 after 72hrs. Never had a problem. Although I usually ferment at 66-67F. These are usually in the OG60 range, give or take. edit: I use WY1968, but whatever.
When I have used that strain, and any english strain, I'll start in the mid 60's and keep it there for about 72hrs or so, like NiceFly. Then take it out of cooling and let it come up to ambient. Especially with 002, I think it's best to drive the end of fermentation with a temperature rise to ensure you get good attenuation and maturation. If you wait until fermentation is done, it'a already to late. That yeast can also benefit from rousing the carboy when it starts to floc out toward the end.
Pretty much what I do with all ferments I've done with English yeast. No diacetyl detected in these beers when I've submitted them to comps. Also, if there is any residual diacetyl left afte the ferment, you can always bottle condition to scrub it.
Every beer I do these days (lager or ale) sees a rise to room temp once the krausen has started to fall. Maybe it's not needed/beneficial for every yeast strain - but it certainly can't hurt...honestly I can only see it helping so long as you're half-way through fermentation (or greater). Unfortunately I've never used WLP002, so I can't comment on this particular yeast. Prost!
