Stuck Muscadine

[Tony49]

On 7/31 I finally got to crush my previously frozen 26 lbs of muscadines.
Put into primary with 3 teaspoons of K-meta.
Next day checked S.G. at 1.095 and stirred in 5 teaspoons of yeast nutrient.
Hydrated a pack of Lalvin 71B-1122. Yeast hydrated well and was active when added to the must.
Stirred each day and on fifth day removed grapes and crushed to juice.
S.G. has not moved from 1.095 since.
Taste is good sweet and color is good.
Fear that I have a stuck fermentation here.
This is my first experience with grapes, so I need a little help in executing my next move.
Do I need a yeast energizer or another packet of yeast?
Hate to loose this nice six gallons of goodness.
Thanks
Tony...

 

[Johnd]

On 7/31 I finally got to crush my previously frozen 26 lbs of muscadines.
Put into primary with 3 teaspoons of K-meta.
Next day checked S.G. at 1.095 and stirred in 5 teaspoons of yeast nutrient.
Hydrated a pack of Lalvin 71B-1122. Yeast hydrated well and was active when added to the must.
Stirred each day and on fifth day removed grapes and crushed to juice.
S.G. has not moved from 1.095 since.
Taste is good sweet and color is good.
Fear that I have a stuck fermentation here.
This is my first experience with grapes, so I need a little help in executing my next move.
Do I need a yeast energizer or another packet of yeast?
Hate to loose this nice six gallons of goodness.
Thanks
Tony...

If you started at 1.095 and five days later it's still at 1.095, it's not really a stuck ferment, it's one that hasn't even started. 3 tsp of KMS is a lot for such a small volume, can you test your SO2 to see where it is? I'd be willing to bet that it's so high you won't get a yeast going in that.

One tsp of KMS is 6.6 g, times three is 19.8g. Using fermcalc, for 6 gallons and estimating a pH of 3.5, your free SO2 is 500 mg/l, or 500 ppm, way too high. Initial dosing for a 6 gallon batch (which I wouldn't do for frozen grapes anyway) would have been about 1/4 tsp.

Typically you don't take your grapes out and press them until your SG is getting down into the 1.010 range, after your fermentation process has had the opportunity to extract all of the goodies from your must.

 

[Tony49]

Prior recipe on this forum asked for one campden tab for each gallon.
Evidently my guestimate for six gallons was too aggressive.
Also advice for muscadines was not to leave the skins on for more than four days. I went Five.
Have no way (or understanding) to test for SO2.
So...Toss it?

 

[Julie]

Don't toss it.

I agree with Johnd, you used way too much k-meta. I would splash rack it a couple of times and make another yeast starter and step feed the must to it. And it is adviceable to leave skins on for four to five days but your must should be fermenting at this time.

 

[Tony49]

Thanks for showing up Julie.
I think this is the second time you saved my butt. (hopefully)
The only yeast I have on hand is Lalvin D-47. Hope this will work.
Fortunately I invested in an "All In One" wine pump.
Should make the job go easier.

 

[Johnd]

Prior recipe on this forum asked for one campden tab for each gallon.
Evidently my guestimate for six gallons was too aggressive.
Also advice for muscadines was not to leave the skins on for more than four days. I went Five.
Have no way (or understanding) to test for SO2.
So...Toss it?

It should be recoverable, it'll just take time for the SO2 to become bound and / or dissipate, although I don't know how long that might take.

1/4 tsp for 6 gallons will get you where you want to be (in the future) and you'll be able to pitch yeast in 24 hours.

The advice to leave the skins in for only four or five days is solid, but I suspect that what was meant, was four or five days of fermenting. They have a foxy, wild taste that gets stronger the longer you extract from the skins.

Dont' toss, as Julie said, try to help it along with SO2 depletion, it's quite well protected at the moment. Once you can get your yeast going, it should do just fine.

Did you throw the skins away?

 

[Tony49]

Thank you.
Hoping the K-meta doesn't affect the final product.

Did you throw the skins away?

Yes.
Thoughts?

 

[Johnd]

Thank you.
Hoping the K-meta doesn't affect the final product.

Yes.
Thoughts?

Well, you'll have lost the opportunity to get some extraction, consider some tannins or oak dust additives during primary fermentation to help with color retention. You got a good long soak on the skins, so focus on getting the fermentation started, maybe add some more grapes if you can find some.

 

[Tony49]

Many thanks...

 

[Tony49]

Yesterday I followed Julies instructions to the letter.
Splash racked several times and step fed a new yeast starter.
This took most of a day.
This morning I was rewarded with some small activity. Took an SG check and found that the SG was now at 1.090. Down five points.
Felt so good, I went out and cut the grass.
At 1:00PM there is a nice covering of frost on top of juice in the primary.
Looks like I may be home free.
Did put in two teaspoons of yeast nutrient by degrees when I saw that the yeast was doing its thing. I'll add some more when the SG drops a bit more.
Thank you both for sharing your knowledge.
Tony...