Notice that the temperature optimal range is much narrower than most white labs products. Also: high flocculators tend to need a lot of oxygen (see: English yeasts like WLP002, 006 and 007), and this strain also likes a lot of oxygen- I've definitely gotten better performance out of it (faster ferments and flocs) since stepping up to pure O2 about a year ago, the only way to properly oxygenate your wort to the optimal 8ppm dO2.
Certain malts, in particular, can be a little off-putting to me, and I pick them up as a slight slickness or butter-nuttiness you might expect from diacetyl.
Wow, so much amazing stuff in this post; you get a "Like!" (and I don't give that many).
Do you have any references or links that support the idea that english strains often require higher levels of oxygen? -I'm not saying that I doubt you, only that data would be appreciated. Honestly it kind of makes sense when you consider the English tradition of open fermentation -English strains could have developed a preference from being fermented in higher oxygen environments.
For what it's worth though the 8ppm isn't a universal recommendation; high gravity worts should have higher concentrations, as should lagers (12ppm starting point); -it's interesting that it's harder to get oxygen to dissolve in high gravity worts AND they actually require more oxygen, too. Reference: Institute of Brewing and Distilling's General Certificate in Brewing- Fermentation Manual (should be available as a PDF free online).
On the diacetyl point: it's awesome that you noticed this. Golden Promise malt ("scottish Marris Otter") is actually FAMOUS for tricking people (with less structured tasting experience) into thinking that they're tasting diacetyl. Brewers are actually slowly abandoning it because Americans taste UK beers made with the malt and they vote down the beer as having a "fault" on beer rating websites despite the breweries use of expensive HPLC testing to validate that no diacetyl and diacetyl percursors (VDKs) are present.
Further on the diacetyl point, diacetyl is SUPPOSED to be in some English beers and personally I think diacetyl really adds to those beers. This modern American jihad against diacetyl, I find really off-putting. Wine makers specifically perform malolactic fermentation on most red wines and some white wines (think California Chardonnay) BECAUSE THEY WANT / LIKE DIACETYL and it adds to the mouthfeel and flavor. -Yes, they also perform malolactic fermentation because it turns harsher malic acid into lactic acid and mellows the acidity of the wine, but ALSO because of the positive flavor enhancement brought by diacetyl.
Personally I think diacetyl is most often delicious; although I have had some rushed lagers that were disgustingly overladen with diacetyl, they're the exception to the rule.
I'm actually even more interested in using WLP 090 again to try and coax that Diacetyl out of it, now.
The Fuller's strain is famous for being a diacetyl producer; Fuller's ESB is possibly the most complex beer for it's strength, bar none and part of that deliciously complex flavor is diacetyl. P.S. ESB's not a style; I'm sorry BJCP but a single beer does not a style make, even if you really like that single beer!
Also interestingly: people generally speak of yeast as "diacetyl producers" but in reality all yeast produce diacetyl and roughly the same quantity; where the strains differ is in their ability to TAKE BACK UP diacetyl and convert it to acetoin. -We taste a beer and say "it's diacetyly; this yeast must produce a lot of diacetyl" when in reality it's just bad at soaking it back up.
Adam
