Which fermentation temperature should I favor?

Question

I am doing a dual brew this weekend. First up will be my Engine 97 Steam Beer (aka California Common - see recipe here: http://www.lootcorp.com/recipes/engine-97-steam-beer.html - credit for original goes to Jamil Zainasheff). I'll be pitching a nice, fresh yeast slurry of WL San Francisco Lager yeast (a really versatile and clean hybrid ale/lager yeast, very good stuff). I like to ferment this beer @ 58*F.

Second batch will be another Jamil recipe - Chocolate Hazelnut Robust Porter (don't have the recipe handy, sorry). I was thinking of using the same yeast, since I have a bunch of slurry, but trying to ferment it warmer to get some esters (like, 68*F).

I have a chest freezer I can ferment both batches at once in, but I will obviously need to pick one temp or another. So do I go for 68 for the porter, allowing for some esters in my Cal Common? Or go 58, making the Cal Common happy but maybe losing flavor in the porter? Shoot for the middle ground of 63?

Answer 1

I was going to suggest keeping one out of the cooler, depending on the temperature of your basement/cellar.

Since you're in CT I'd guess (based on geography, not experience) that your cellar temps would be in the mid to high 60's, so that should be good for your porter.

Answer 2

Really tough spread there. If you are really willing to sacrifice one for the other I'd go for the cooler temp and favor the Cal common.

Have you considered the use of a swamp cooler for the porter? That way maybe you can get a good yeast profile for both beers.