I brewed a 16-gallon batch of my Lawnmower Lager, popped it into my Brewhemoth and inoculated it with 3 packets of Saflager S-23. My chilling solution isn't working as well as I'd hoped, and it's currently around 60F after about 16 hours - I've just got some bubbling in the blowoff. I expect it'll be in the mid-to-high 60's when I get home from work today due to fermentation kicking into high gear. I was hoping for 53-57F.

I've got some plans to get the temp down, but if I can't I'm going to call it a California common/steam beer and hope for the best.

Which brings me back around to my question: since a steam beer is typically fermented with lager yeast at ale temps from the start, won't it generate a ton of diacetyl? And since you're already at ale temps, how do you do a diacetyl rest to clean it up?

1 Answer 1


The warmer the fermentation (to a reasonable point) the more active the yeast is and the less diacetyl you'll get. To do a diacetyl rest for an ale, you just leave it on the yeast longer. It's not the temp that matters for a d rest. You raise the temp for lagers in order to make the yeast more active, but the actual temp (again, within reason) doesn't really matter. Considering the yeast you used, you may have lucked out. S-23 can be almost disgustingly fruity at normal lager temps. It seems to work much better in the 60s.

  • The yeast need to be kicked up a metabolic gear or two to break down the diacetyl, that's normally left unconsumed during larger temp fermentation. You're above lager temps, so should be fine. If you wanted to be sure you could up to 70F at the end of primary. S-23 does get fruity, even in the 50s in my experince, so I try to avoid it.
    – mdma
    Commented Jul 17, 2012 at 19:02
  • I managed to get my temps under control, but this answer is just the info I was looking for. Thanks to you both for the comments about S23 as well. I'm keeping the temp a few degrees higher because of them.
    – JoeFish
    Commented Jul 18, 2012 at 3:30

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