Quick fermentation, then... nothing

[Dr. T.]

I cooked up a 5 gallon batch of Caribou Slobber, and it's in my fermentor. Made a 1 L starter, which was active before pitching. About 6 to 8 hours later I noted some fermentation occuring (CO2 evolution), the next day it was crazy fast (had a blow off tube on it), and by the end of the next day it stopped. Full stop. I removed the blow off tube for a standard bubbler, and as far as I can tell, nothing is happening. I'm holding the temperature at 69 C.

Has my fermentation stalled? Is it done? Or am I just waiting for the last couple percent of sugar to be fermented? I can't imagine there are any leaks.

- Thanks!

 

[Rob2010SS]

Are you fermenting in something you can see through or no?
How long has it been since you pitched yeast?

My guess is it's finishing up the last little bit of sugars. Fermentation really doesn't take that long if it's a healthy fermentation. You'll usually go through a stage of VERY active fermentation and it'll slow after a day or two and gradually come to a stop.

The reason I ask if you can see through your fermenter is if you can still see krausen on top, it's still going. Usually when fermentation activity ceases, the krausen drops. Not always the case, but more often that not it is.

The reason I asked when you pitched yeast is really just to confirm that it most likely is still going. If you pitched a week or more ago, you could very well be done. If you pitched 3 days ago or something like that, you're most likely still going. As always, airlocks aren't a measure of fermentation activity. The best way to tell if you're done is gravity readings 2-3 days apart. If they're the same, you're done.

 

[RM-MN]

The temperature at which you ferment the beer changes this timeline a little but this is what goes on in fermentation.

http://www.brewgeeks.com/the-life-cycle-of-yeast.html

 

[Dr. T.]

I can see the fermentation, and the krausen has gone away. I pitched the yeast starter about 3 days ago, so it hasn't been long at all. After the initial vigorous fermentation (and about 1.5 inch krausen), it's now looking like it's taking a nap. I plan to let it sit for a couple weeks as I would normally, anyway - just thought this was a weird observation. Thanks for the web link, RM-MN

 

[Brewers Hardware]

Sounds like you just had a very healthy fermentation. I've had yeast rip through beers and be done in a couple of days and others that liked to take their time.

 

[McKnuckle]

It's not at all weird. Primary fermentation is quick if the yeast are plentiful and healthy, and you fermented warm at 69F. What remains of krausen is largely yeast strain dependent. Perhaps the strains you've worked with before were not as flocculant as this one is. Krausen can drop in 2 days, or it can stubbornly stay on top nearly forever - all depending on the type of yeast.

I'd wait out the full week just for good measure, then take a gravity sample and move on to conditioning.

 

[Dr. T.]

Thanks for the tips. I do think it was a lively yeast. It held its own temperature at 72 C during the rapid fermentation, then it dropped to 66 C (my basement temp). I'm now raising and holding at 69 C incase it needs more energy. I'll check it in one week, as recommended.

 

[Dr. T.]

BTW - home brewing is a good coronavirus hobby

 

[Rob2010SS]

BTW - home brewing is a good coronavirus hobby

Hell yeah it is! As long as you have enough supplies, which I do not, sadly.

 

[RM-MN]

Thanks for the tips. I do think it was a lively yeast. It held its own temperature at 72 C during the rapid fermentation, then it dropped to 66 C (my basement temp). I'm now raising and holding at 69 C incase it needs more energy. I'll check it in one week, as recommended.

Note that in the link I posted it has a timeline for the yeast to propagate. You mostly bypassed this step with your starter so your fermentation went quick.

 

[wsmith1625]

Thanks for the tips. I do think it was a lively yeast. It held its own temperature at 72 C during the rapid fermentation, then it dropped to 66 C (my basement temp). I'm now raising and holding at 69 C incase it needs more energy. I'll check it in one week, as recommended.

Just noticed you put all your temps as Celsius when you obviously mean Fahrenheit.

 

[Imhoppy]

Brewed Caribou Slobber twice. These were extract kits using Danstar Windsor Ale dry yeast (pitched dry). Needed blowoff tubes on both due to violent fermentation. Batch 1 took 8 hours from yeast pitch to active fermentation, then pretty much done 26 hours later. Batch 2 took 5 hours and then 32 hours respectively. Both batches turned out great. Don't see any problems Dr. T. Relax and enjoy!