I don't know what it is, but I have never had satisfactory results from SO4. I've used it in multiple stouts, a Scottish ale, and a cider. I always use nutrients, and aerate very well. I ferment in buckets in an STC-1000 controlled fridge, with the probe taped to the side of the bucket under a couple layers of bubble wrap. I've always controlled the temp to the low 60's and once in the mid 60's. I usually rehydrate, but twice I've just sprinkled it. Without failure, every single batch that's used this yeast has had way over the top esters, and tastes like it fermented way warm, but I know none of them have (verified with a different temperature probe side by side w/ stc probe).

I've used other yeast to great success, including US05, WLP004, WLP080, and WLP090. They've all come out clean and great tasting. The SO4, on the other hand, is palatable in a stout due to the roast and chocolate covering it up partially, but the rest were damn near undrinkable.

Has anyone else had this experience? My only thought at this point is the temperature I bottle condition at. The house is usually in the mid to upper 70's, but occasionally gets hot, getting into the lower to mid 80's. I have no way to bottle condition lower than room temp without tying up my fermentation chamber the whole time. I've always read that bottle conditioning temperature doesn't matter as much, as long as it's not excessively hot, or excessively cold. Could the SO4 be much more temperature sensitive than the other strains and throw off a lot of flavors during bottle conditioning?

Any thoughts? Thanks in advance.