I was looking for a place to post this regarding WLP29...I've made 3 Kolsch with vary levels of success, almost certainly due to variations in yeast performance.
The first was quite nice, fermented around 65F. For some reason I decided I would have liked a little more of the vinous character that some Kolsch have, so the next time I made it, I fermented somewhat higher...maybe 68F or so. That one was a disaster...the beer never cleared despite well over a month of cold conditioning in the keg, and even gelatin. It wasn't just the appearance, but the yeast flavor could be discerned easily and destroyed the delicate subtlety that you look for in the style. It wasn't a horrible beer, but it wasn't a Kolsch at all.
Last one I did I fermented cooler...I think maybe 62ish, trying to avoid the disaster of the 2nd, and it was decent, but had a noticable acetyldehyde note that didn't go away. It was OK, but the green apple bugged me with every glass.
My thinking now is that the 2nd batch was pretty much a fluke, or something else was wrong with the yeast health beyond the fermentation temp. I did starters for all three and I should have had good yeast health and cell count for all, but maybe something went wrong with #2 that I didn't perceive when I pitched.
My next Kolsch I'll do around 65-67 and try to make absolutely sure I have the right cell count and no other issues, but I'm curious as to others experience with this yeast. I know it's supposed to be quite finicky and my own experience certainly bears that out. What fermentation temps do people usually use? Any other tips, dos and don'ts that I may not have thought of?
Sorry for the long post--any feedback/advice is welcome!