What can I do to stop the fermentation?

[bpaulik]

Hello, I am looking for some advice. I am making my second mead ever and I think I have a problem. I was attempting to make the “Cherry Dangerous Mead” from the AHA recipes site. My initial fermentation went well and I ended up have a FG of 1.003, I transferred it to a secondary and added 4.00 grams of Potassium Metabisulfate and 2.83 grams of Potassium Sorbate to 6 gallons of mead to kill off the yeast. I left it in the secondary for roughly 72 hours. I then transferred it back to my original (cleaned) fermenter and added 15 lbs of fruit and it appears to be fermenting. Is there anything that I can do at this point to kill off the yeast since it appears the additions of Potassium Metabisulfate and Potassium Sorbate didn’t quite do the job? I thought I added enough of each but, maybe not.

Any advice would be greatly appreciated.

 

[bpaulik]

I apologize, I posted in a panic and afterwards I saw @Tywalker post "Mead won't stop fermenting". I read through that, and I have now taken a gravity reading (1.027). I will wait a couple of days and take another to see if it is truly still fermenting or if is just off gassing.

 

[Maylar]

4 grams? Really? That's like 2.5 times the recommended dose.

 

[beren]

You don’t. You let it run out of sugar.

 

[bpaulik]

4 grams? Really? That's like 2.5 times the recommended dose.

This is where I came up with 4 grams. Although I didn't check the PH. I just figured I would be ok using this much.

 

[Raptor99]

What is the pH of your mead? 4.0 would be very high. My mead is often around 3.2 to 3.4 pH.

Here is a chart that I have been using to determine how much Kmeta to add:

Desired Free SO2	Kmeta
pH	ppm=mg/L	g/gallon
2.9​	11​	0.073​
3.0​	13​	0.086​
3.1​	16​	0.106​
3.2​	21​	0.139​
3.3​	26​	0.173​
3.4​	32​	0.213​
3.5​	40​	0.266​
3.6​	50​	0.332​
3.7​	63​	0.418​
3.8​	79​	0.525​
3.9​	99​	0.657​
4.0​	125​	0.830​

The table formatting comes out strange in the post, but on the right you can see the g of Kmeta per gallon. pH 3.0 requires 1/10 as much Kmeta as pH 4.0. So it is important to know the pH.

 

[MightyMosin]

I use a very similar chart to that, though I only have down to a pH of 3.2.
I use this same approach as it better than the broader shotgun approach of xx per gallon.

The best is to use a meter to actually measure it, but I haven't moved to that yet.

 

[bpaulik]

I need help here again.

I transferred the mead off the berries, and it continued to ferment. Two days after I added the fruit the SG was 1.027, three weeks later, and I'm at 1.009 with a PH of 3.77.

Can I add the Potassium Metabisulfite and Potassium Sorbate again so I can back sweeten? If so, how much would I add of each?

From what I can tell, I need 2.62 grams of Potassium Metabisulfite for 6.25 gallons. For the Potassium Sorbate, my original SG was 1.083 and fermented to 1.003. This gives me 10.7% alcohol. After adding the berries, I had 1.027 and it fermented 1.009. This gives an additional 2.36% for a total of 13.06% which would mean I would need 2.369 grams of Potassium Sorbate.

 

[bernardsmith]

I wonder if you may be using the wrong chart to determine the amount of K-meta to STABILIZE (not halt) a fermentation. Stabilization is to prevent yeast from refermenting, AFTER fermentation has fully ceased when you add more fermentable sugars (fruit etc). Typically, , K-meta has several purposes. One purpose is to iinhibit oxidation upon racking and when bottling - and to do that we add the equivalent of 1 campden tablet (.44 g /tablet of K-meta PER GALLON together with 1/2 teaspoon of K-Sorbate per gallon. Both need to be added together. To inhibit oxidation, you need to add about the equivalent of 1 Campden tab per gallon: the idea being that you want 50 ppm of freeE sulfur which is what each tablet will provide at the typical pH of most wines we make. The lower the pH (the more acid, the wine) , the less the amount of free sulfur needed.

 

[bpaulik]

The chart that I am using is from https://meadmaking.wiki/en/process/stabilization
and I am using Potassium Metabisulfite and Potassium Sorbate (Sorbistat K) from MoreBeer. I did end up adding the amounts that I have listed above.

2.62 grams of Potassium Metabisulfite
2.369 grams of Potassium Sorbate