Thu Jul 02, 2009 2:02 pm
The trick with the DuPont saison strain is to propagate warm, pitch warm, and ferment warm - generally no cooler than 75F, and no warmer than 95F, and be patient. The strain in question is actually very closely related to red wine yeast, more so than most other Belgian strains. Since its a farmhouse strain it's probably been condition/selected for higher temperature fermentations. As far as flavors go, you'll get banana/tropical fruit esters at 75-85F, and phenolics/spices at 85-95F. Assuming you pitch the appropriate quantity of yeast and oxygenate, you will not detect any fusel alcohols in your beer at these temperatures.
Last year I fermented a batch out by holding the temp at a steady 83F - OG was 1.049 (all malt), FG was 1.008 - took 5 weeks to finish, although I'm sure I could have gotten it down to 1.006 had I waited another month.
I've got another batch that sadly was cold shocked by a wave of mild summer weather, dropping the temp down to 67F while I was away, stalling fermentation at 1.020. I transferred it to a conditioning tank (corny keg w/trimmed dip tube) and was able to start it back up again with a fermwrap raising the temp slowly to 85F, but I think I'll mix it up this year and drop some Brett into the keg to finish things out and give this beer an even more interesting character.