Interesting observation about US-05 and diacetyl

[stickyfinger]

I started a small homebrew club in my basement after I built my 16-gallon-max HERMS setup, and we've been sharing the wort and doing 2.5 gallon batches. We split up the 16 gallons and we each ferment our own wort. I've noticed a trend over several batches. When one of my friends uses US-05 yeast, he ALWAYS has diacetyl problems. His apt. is pretty warm, especially over this summer. He HAS used other yeast over this summer though as well, under presumably the same conditions, Pacific Ale yeast and San Diego Super Yeast. None of his other beers have had diacetyl, just the ones with US-05. I'm wondering if US-05 is particularly likely to create diacetyl under warm fermentation conditions or if maybe it's because it is dry yeast. He hasn't made starters for any of the beers, and his FG numbers are very respectable.

I uses US-05 all of the time in my fermentation fridges, and I get awesome results, so I'm pretty sure it is due to the temperature, especially considering his other beers have been fine using liquid yeast of other varieties.

Just an observation that I found interesting.

By the way, I've also learned that shockingly low pitching rates can result in fantastic beer that is well attenuated, not that I don't pitch appropriately!!

 

[gcarter]

Interesting read that may help:

http://www.professorbeer.com/articles/diacetyl.html

Perhaps he is packaging too early?

 

[stickyfinger]

Yes, this may help, most likely. But, he likely treats all beers the same, so it's interesting that US05 may be particularly diacetyl-prone under certain conditions.