View Full Version : Stuck fermentation?

08-11-2005, 02:49 PM
I started a batch of mead (my first) on 7/30, and it's now looking like fermentation may be stuck. I was trying to approximately duplicate Chaucer's in terms of alcohol and residual sugar. Here are the particulars, for a 3 gallon batch:

11 lb wildflower honey (from a local beekeeper)
1 1/2 tsp LD Carlson "yeast energizer" (yeast hulls, DAP, and other stuff)
Balance water to 3 gal.
White Labs WLP720 (Sweet Mead/Wine) yeast.

I prepared a 500 mL starter a couple of days in advance.

SG at the beginning was calculated at 1.127 (I measured 1.140, but I then had to add more water). I oxygenated with pure O2 through a diffusion stone, and then pitched the yeast starter. The next day, the airlock was bubbling about once/2-3 sec.

One week later, on 8/6, the airlock was bubbling once/4-5 sec, and SG was measured at 1.092.

Tuesday, 8/9, the airlock wasn't bubbling at all. Concerned, I decided to add some yeast nutrient, and weighed out 3 grams of Fermaid K. I added that to the must and swirled it to mix in the Fermaid.

Yesterday, 8/10, the airlock still wasn't bubbling. SG was 1.080.

I'm going to test SG again tonight, and if it still reads 1.080, I'd expect it's stuck. I'd like to finish up around 1.040.

A friend of mine has recommended pitching new yeast. I have a couple of packets of K1V-1116, and could certainly rehydrate and pitch one of them. If I do that, should I aerate/oxygenate again? Should I pitch new yeast at all, or is there something else I should try first? Thanks for any suggestions!

08-12-2005, 08:57 AM
Checked SG last night, and it was still at 1.080. Rehydrated a packet of K1V-1116 and pitched it in to the must. This morning, still no bubbles in the airlock. There's a bit more foam on the surface of the must than there was before I pitched the new yeast. If there's no activity by this evening, I suppose I'll oxygenate again and cross my fingers--any other suggestions?

08-12-2005, 09:58 AM
If that doesn't work,

Make a starter.

After the starter is going well,
Put the starter in a new fermenter.

Add the same amount of your must to the starter.

When that is going well, Double it again.

Keep doing this 'till all of your must is in the fermenter, fermenting.

Has worked for me with difficult ferments.


08-13-2005, 10:28 AM
Latest news:

Last night (8/12), there was still no bubbling in the airlock, so I re-oxygenated (twice, 30 sec. through a 0.5-micron diffusion stone) and stirred the must with a sanitized racking cane. This morning, still nothing in the airlock. However, I did notice a lot of small bubbles at the surface, and they appeared to be coming and going pretty frequently. SG now reads 1.074.

It's looking like it's (still/again) fermenting, though quite a bit more slowly than I'd expected from K1V. Do I just need to be patient?

08-13-2005, 03:38 PM
How much headspace you have in your fermentation vessel?

Check your pH, and check the dates on your yeast packs as well to make sure they're within lot specs.



08-13-2005, 10:38 PM
Headspace is about 2 gal. worth--it's a 5 gallon carboy, and the batch is 3 gal. The yeast I originally pitched had a 9/30/05 expiration date, and the packet of 1116 listed 12/05. Don't have pH testing equipment at the moment, have to check back.

08-14-2005, 12:04 AM

That's a lot of headspace in your primary. I wouldn't be surprised that you're not seeing a lot of bubbling going on. The CO2 is having to fill up that void before you see the fermentation activity.

I'd suggest being patient and watching the must itself rather than just the airlock. See if the must is bubbling, if it is, just keep an eye on it and check your gravity in a few days.



08-14-2005, 10:48 PM
Thanks Oskaar. The must is bubbling, so I expect it's OK. I know the saying is to "don't worry, relax, have a homebrew", but I can't do that yet. ;)

08-20-2005, 12:30 PM
A week later, and no visible change--there's still light bubbling at the surface of the must, but no activity in the airlock. However, SG is down to 1.062. It is apparently working, just much more slowly than I'd expected. Patience, young grasshopper...

08-23-2005, 08:49 AM
A week later, and no visible change--there's still light bubbling at the surface of the must, but no activity in the airlock. However, SG is down to 1.062. It is apparently working, just much more slowly than I'd expected. Patience, young grasshopper...

You obviously have a bad seal somewhere as your description shows it definitly fermenting. Check all your seals to determine where the CO2 is going instead of through your airlock.


09-06-2005, 03:21 PM
Must have been a bad seal of some sort, though I'm not sure where it could have been--the cap was firmly in place, and I didn't see any cracks or holes. In any case, a week ago, it was at 1.052, and this past Sunday, it was at 1.050. That's about where I wanted it, so I racked it into another carboy over some campden and K-sorbate to stop fermentation.

I'm suspecting, from the slow-down in fermentation, that the K1V never did really take off, and this was just the original yeast doing its thing. I'm not sure why the K1V wouldn't have taken off, but that seems consistent with what I'm seeing there. Thanks for the suggestions!