Quick question: what happens when WLP029 German Ale/Kölsch ferments at the high 50’s? I had read that I should ferment this in the low-mid 60’s, so I pitched a 3L stir-plate starter (decanted) into 5.5 gallons of 62 degree wort, with the intention of keeping the fermentation temperature to around 64F by leaving my fermentation. For some reason, my fermentation freezer didn’t warm up as much as I’d expected, and the beer is fermenting fairly vigorously at 58F. I am trying to raise the temperature to 64, but clearly this beer has been fermenting at 58F for at least 12 hours at this point. What should I be expecting?
I think you’ll be just fine. I routinely pitch WLP029 into my kolsh at 55, let it run at 58 for 3-4 days, then warm it to 62 to finish.
For what it’s worth, my last Kolsh I fermented this way took 1st prize in the NHC first round this year.
That’s good news. I was planning on building up the yeast from this 5.5 gal altbier and pitching the whole cake into a 12 gal Kölsch. What’s the lag time on this yeast? How long should I expect it to be before I can drink this altbier?
Deliciousness ensues.
If the carboy’s rockin’, don’t bother knockin’. That yeast works great at that temp. 3 NHC first round medals that way.
I have to agree with Gordon in that “deliciousness ensues”.
This yeast performs best between 58-60F. It has a fantastic fruity ester character that works so well with German Pilsner. I make a Kolsch every Summer and it goes quick. I highly recommend this yeast.
That’s a perfect temperature. Let the yeast run with it. I just brewed a Kolsch this past Friday and pitched at 58F. Six hours later, it was actively fermenting and has been going steadily since. I’ll bump the temp to 62F in a few more days to make sure it finishes. Then lager until the weather here starts to get hot.
I have a “cream ale” going right now at 52F … and it goes great. The past three batches of the cream ale fermented at 52F to 54F, have medaled 5 out of 5 times.
The only thing I have found with that yeast is that you HAVE TO make a starter. Otherwise the lag time, even with a fresh tube in a 3 gallon batch, will have a lag time measured in days…Once it has “woken up” up though, it will rock’n’roll in the 50s just fine.
Lastly, you may wish to let it lager for 3 to 4 weeks as well. I have found a great improvement during that time, and if you can give it two months… it is fantastic!
Enjoy!
This has been my experience as well. Lagering this beer does wonders. The colder the better. 
Well, my alt spent a couple days chugging at 58F and now it’s going strong at 62F. I will let it ride there for another week or so before I raise it to ambient for a few days while I let my fermentation chamber take on an IPA. Then I will rack the alt into a corny and pitch the slurry into 12 gallons of Kölsch which I will probably also ferment in the high 50’s now that I know the yeast can take it.
I suspect you’ll be very happy with the results. 
Let us know how it turns out.
I would pitch about 1/8to 1/4 the slurry into the kolsch. (assuming good yeast health, proper oxygenation in the last beer…etc) Pitching the full slurry is just too much yeast. (assuming same batch size).
My personal progression for this yeast is 2L yeast starter → 3 gal cream ale (1/2 yeast slurry into) 5 gal Alt 1/2 into a 5 gal Kolsch. After that my fridge is full for the first half of summer.
This tends to be over pitching the yeast, but the results are good for me. Based on what I have been reading lately, I think that if I went to pure O2, the yeast health would be better and I could cut down on the quantity of yeast slurry to start.
Either way, keep the kolsch yeast at 52 to 58 and love the results!!!
I have a Kolsch (brewed 4/23) in the fermenter using this same yeast. It has been bubbling away nicely around 58-60 degrees since. The gravity on Monday was 1.020 (1.046 OG) so it’s getting close. Do I need to raise the temp a little? This is my first time using this yeast.
This strain has a tendency to stall under temps of 62 degrees, especially near the end of fermentation. Definitely raise temp to the mid 60’s near end.
This yeast sure takes a long time to finish! My alt is still bubbling away at 62F. I was waiting for it to slow down a lot before I brought it to ambient for a week before cold crashing and racking.
It’s taking a long time because it is not the best cold fermenter. I always start mine out at around 58, but let it raise to 62 and then finish it off in the mid to high 60s. Have had it stall many times under 62.
What should I expect for a Final Gravity?
How long is a piece of string? It’s gonna depend on a lot of things. Mash temp, assuming you are all grain brewing. If not then the fermentable potential of you extract and wether or not you added crystal malt or not. Give a recipe and we can maybe point you in the right direction.
That said, for a kolsch I’d look at around 1.009-1.012.
All grain Kolsch 12 gallons
20# Pils malt
2# Munich
Mash at 150 for 1 hour, batch sparge.
OG= 1.046
I was kind of thinking that 1.010 for a FG would be good.
Thanks for your help.
Yeah, sounds about right. 1.010 give or take a point or two. Also, were you sure to pitch an appropriate amount of yeast? A kolsch needs a rather big pitch of yeast. Not quite as big as a lager but generally more yeast than a standard ale.
Agree with the advice here. Let it rise in temp towards the end, just like you’d do with Belgian yeast. And 1.010-ish is a good FG. Be sure to give it time to cold-condition after fermentation is done. You will likely have to fine it (gelatin is OK) to get it crystal clear; it’s important for the style. The Kolsch yeast is powdery and doesn’t like to floc too well.