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Swamp bath may have caused stuck fermentation?

Hi all. This is my first post and my first batch. Purchased the NB essentials brewing kit with the Caribou Slobber extract recipe kit. I’ve done my homework so to speak and read Palmer’s How to Brew book. Brew day went perfectly but I’ve hit a snag and was wondering if someone else has run into something similar. I think my “swamp bath” may have resulted in a stuck fermentation. BTW, I searched the forums for stalled fermentations but didn’t find anything that directly answered my questions. Here’s what happened:

  1. Sanitation and brewing process went perfectly.
  2. Rehydrated 2 packets of dry Windsor yeast at around 75 degrees. Lots of activity in the measuring cup.
  3. Chilled wort to about 76 degrees with immersion chiller.
  4. Transfered to 10 gal ss pot.
  5. Aerated the wort with oxygen tank and wand. Read this wasn’t necessary with the Danstart Windsor yeast but figured it could only help (which is why I purchased the 2nd pack of yeast).
  6. Checked gravity with hydrometer. OG was right on at about 1.051 or 1.052.
  7. Pitched the yeast at 76 degrees.
  8. Placed the fermentation bucket in tub with blow off hose plugged into jug of star san.
  9. It started bubbling about 3 or 4 hours later then I went to bed dreaming dreams of porters and stouts. :slight_smile:

About 8 hours later the next morning, the fermentation/bubbling was going crazy which I was happy to see but then panicked when I checked the temp and it was 74 on the outside of the bucket. I realize the fermentation activity can raise the temp anywhere from 5 to 10 degrees but I read that the optimal fermentation temp for this recipe is 65 to 70. So I started filling the tub with cold tap water (no ice) and all activity stopped within about 10 minutes or so. I think it stopped when the water got around the 3 gal mark. The temperature of the tap/bath water was only about 68 degrees but I’m concerned I shocked the yeast by dropping the temp on it so fast. The bucket never got hotter than 74 or cooler than 68. It’s been over 24 hours and the thing hasn’t bubbled again since. I’ve shaken it gently and then vigorously later that day and still no activity.

Sorry for the long post. Does this sound like a stuck fermentation?


Unlikely that chilling the beer 6F would cause the yeast to stop. Check the gravity.

" I checked the temp and it was 74 on the outside of the bucket"

Was the temp reading from one of those thermometers that you stick on the bucket? I read somewhere that they give a pretty accurate reading on the wort temp so you could be okay, 74 is not the best but it’s not terrible, only time will tell.

Probably not the most reliable method but I used one of those $40 laser thermometer guns to check the outside temp. I have one of those fermometer strips but didn’t bother sticking it to the bucket yet. Will do now. Thanks for the feedback guys.

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