Now more than a month later I am prepared to share some results!
My primary goal with blending US-05 with S-04 was to see if the super flocculating S-04 would help to pull out the low flocculating US-05. US-05 always seems to take more time to clear out, flocculation starting somewhere after day 10 in primary. S-04 on the other hand tends to finish up and start flocculating within 3-5 days.
In this first pass experiment, I was pleased to witness that the total yeast suspension was falling out of solution very rapidly within 5 days. By 14 days my final gravity (1.012) was achieved and the beer was basically clear. I used a glass carboy just for the purpose of monitoring the yeast activity. The yeast cake was very tight (as you see with S-04), but not as firm as you normally see with S-04 alone. Perhaps this is a result of the combination with the lower flocculator US-05.
The secondary result is the taste. I would say that the flavor is stil very English. The ester profile still seems like the traditional S-04. I would have thought that the two yeasts would have maybe made a mellower English profile. The flavor is still good though and I would probably try this blend again when shooting for a well attenuated English styled ale.
Hop flavor did seem a bit diminshed though. For all the Cascade hops in there I would have expected more bitterness. But the hop “pop” you get when using US-05 alone isn’t there. Again, this sort of profiles the English yeast again. I think the bitterness and flavor gets a little lost with the roasty malts and the ester profile of the S-04.
Head formation and retention seemed to be normal for either yeast.
Overall, then I don’t think that the blend really gave me something in between the US and English profiles. Perhaps the clean-ness of the US-05 just still lets the S-04 character shine through. While this is not an extensive test (and I hate making and reading about one time experiments as a definitive answer), I found the results useful. I will definitely try this experiment again as working with the dried yeasts is easy. A great test for this “co-flocculation” experiment would be to blend some German Hefe-style yeast with S-04 and see how much of that pulls down. I would not be looking forward to those flavor combinations though.
If it ever warms up here and I get my garden hose unburied from the snow, I’ll brew up the Cascade Pale Ale to accompany the Brown Ale…with the yeast blend for sure.