Kolsch Yeast Fully Attenuated, Still Has Krausen

We did a split 10 gallon batch of Centennial Blonde, 5 gallons with Wyeast 1056 and 5 gallons with Wyeast Kolsch yeast. It's Day 9 of fermentation. The batch started at 1.044 and both appear to be done, spending the past 3 days at 1.010. The American Ale batch "looks" done - krausen's dropped and the samples are nice and clean. I will be bottling by this weekend. The Kolsch, which I know is supposed to be a low flocculator, "looks" like it's still busy at work with a 2"-3" thick head of bubbly krausen.

This is creeping me out, since my hydrometer is telling me it's done "working". I was assuming I'd be lagering this one soon. Does krausen mean the Kolsch is still active?

This thread is somewhat related: https://www.homebrewtalk.com/f163/kolsch-yeast-normal-188961/, but I'm pretty confident that my yeast is done attenuating. I've slowly raised the temp over the last few days, and am assuming that the yeast cleanup will be done over the next few days.

If the krausen is still there when I'm ready to lager, any additional opinions? If it's done working this quickly, I'm tempted to just cold crash it and leave it in the primary.

did you get 3 steady hydrometer readings for 3 days? it never hurts to let it sit for an extra week or two but it does hurt to bottle too early.

Yeah, 3 samples, 3 days, both batches all at 1.010. I'm not in a huge hurry with the kolsch blonde, but am assuming that if I let it ride another few days the yeast will have done their job. From reading that other thread, it might still have that krausen for weeks if I don't cold crash it. I did a wheat beer with a kolsch yeast last year and don't remember the yeast doing this. Just baffled by this.

I've seen similar when using Wyeast 2565. I scraped off the krausen after 10 days and a steady hydrometer and racked to a secondary. I do not lager my Kolsch but do ferment and then secondary between 60 and 65 F for another couple weeks. I learned the hard way to let the beer come upto room temp for a couple weeks when conditioning if bottling so the yeast can build C02 and then I go back down to the 60 to 65 F to condition for a total of 6 weeks condition. It turns out not crystal clear but not bad, very crisp, well carbed and with a very pleasant delicate floral finish.

Yeah, I've used this yeast with a few different styles and it always hangs around. I just cold crash it once I'm convinced it's at terminal gravity. Be warned, takes a LONG time to clear up.

Thanks for the feedback. Anyone ever cold crash and let it sit for a month near freezing on the primary? Since it fermented quickly, I am not worried about autolysis, and can avoid exposing it to a transfer to secondary. Another month in the fridge on the yeast mass should be fine, right?

I would be more than willing to try it if Kegging. You will kill the yeast.

I had same issue with the wyeast Kolsch strain. It was weird. I'd give it till the 3 week mark, rack and cold crash. It benefits greatly from the cold crashing, it was nearly clear at 3 week mark for me, two weeks in fridge boom.. Good beer!!

We still bottle - I always add a few grams of dry yeast back after extended lagering to the bottling bucket just to be safe.

Day 13, the Kosch Centennial Blonde still had krausen but it's been done attenuating for nearly a week. I put it in the fridge this afternoon at 34 degrees and it's already started dropping krausen.

Final update: All of the Krausen fell back into the beer within 2-3 days in the fridge. I lagered it on primary for about 3 weeks, then bottled both the Kolsch Centennial Blonde and American Ale Centennial Blonde. We did a taste test of the two tonight, and at this point we prefer the Kolsch version over the Am. Ale version. I think I will use the Kolsch yeast more often on the light-bodied ales - next up is a cream ale with Kolsch yeast.

Krausen like beer head is formed by off gassing of co2, off gassing can keep happening even once fermentation is finished. As you raise the temp some people see the krausen return and the air lock bubble and think that the beer is fermenting what is happening is the increased temp leads to less co2 being able to stay in solution so it bubbles off. The reverse happened when you chilled yours as more co2 can be dissolved in cold beer the wort stops bubbling when you chill it. I hope this explains what you saw.

Clem