Stuck fermentation?

[cellardweller]

I recently purchased 6 gallons of ice wine juice from a local grower in upstate NY. The Brix was off the chart on my hydrometer. I'm guessing 50+? I added the obligatory crushed campden tablet to the juice and let set a day before pitching EC1118 yeast. I also added yeast nutrient and energizer per recommended doses. It has been nearly 3 weeks and I have not had any fermentation start. After a week or so, I pitched another packet of 1118 to try and kick start a ferment. Still nothing. My basement is about 65°. I drew off about a quart of must and brought it to a warm room in the house and hit it with another dose of nutrient and energizer. Still nothing..... What should I do next? I've got about $100 tied up in this juice. I'd hate to have to dump it.

 

[cmason1957]

Are you certain you aren't supposed to dilute it with some water?? I doubt you will get something with that high of a starting SG to begin fermentation. I believe the osmatic pressure from that much sugar renders the yeast ineffective, much above 40 Brix or so. (and someone who really knows the number will probably tell us what it is).

 

[VinesnBines]

I've never made ice wine but here is a link. https://brocku.ca/ccovi/wp-content/uploads/sites/125/make-icewine-easier-Icewine-paper-non-ref-VWM08.pdf
Takes awhile to download but it appears you are going to reduce the Brix to no more than 42. Brix over 52 is unfermentable.

If you know the variety of juice you need to get some to reduce or add water.

 

[Mead Maker]

I was taught that 23.5 Brix is ideal for yeast. You need to mix in a lot of water.

I use 1 package of champagne type yeast mixed with 1/4 cup sugar and 1 cup of 105 degree water in a tall container.

after a few hours it should be rather frothy. Then mix up another 1/4 cup sugar and 1 cup of 105 degree water.

Mix the 2 containers and set aside.

When they’re both frothy do it again so you have 4 frothy containers.

I call it a “yeast bomb.”

I find it’s a good way to start any wine and a foolproof way to jumpstart a stuck fermentation.

 

[Rice_Guy]

Like @Mead Maker says the sugar may be too high. It would be interesting to see if you can get a reading on a one to one dilution with water. Gravity is a linear function so we could subtract 1.000 from the reading and estimate based on your actual dilution ratio.

For where you are, I would either do a yeast starter and step feed the high sugar juice into it winding up with a port, or dilute it down to 1.120 or less and run it like a normal wine (defeating the purpose of ice wine).

High sugar solutions are microbiologically stable, ,, example maple syrup or honey. There shouldn’t be any health issue in the stuck fermentation, ,,,,ie I would not toss it but run a process like one would do to run a mead.

 

[sour_grapes]

I was taught that 23.5 Brix is ideal for yeast. You need to mix in a lot of water.

No, no, the OP is making Ice Wine. This is meant to be started with a high SG: In Germany, 26-30 Brix is required; in Canada, 35 Brix.

Ice wine - Wikipedia

The high sugar level in the must leads to a slower-than-normal fermentation. It may take months to complete the fermentation (compared to days or weeks for regular wines) and special strains of yeasts should be used. Because of the lower yield of grape musts and the difficulty of processing, ice wines are significantly more expensive than table wines. They are often sold in half-bottle volume (375 ml) or the even smaller 200ml bottle. New World wineries in particular sometimes bottle 200 ml and 50 ml gift packages.

 

[Mead Maker]

Sour Grapes seems to be splitting hairs. I said 23.5 Brix was ideal, which isn’t all that far off the 26 to 30 Brix required in Germany when making ice wines.

If Cellardweller started with 50+ Brix, he would have to add a lot of water to get down to a sugar solution that wouldn’t kill his yeast.

An article in the Journal of Applied Microbiology noted an upper limit of 40 Brix for economic ice wine production. Any higher starting Brix and alcohol production dropped greatly.

The Wikipedia article Sour Grapes included notes that special strains of yeast should be used.

The aforementioned study showed that even when wine vats were left open to the native yeasts, Saccharomyces yeasts, which we all use, quickly overcome the native strains.

Champagne style yeasts, like EC-1118 or Premier Couvee are the way to go. Ice wine is supposed to be sweet, so just kill it off with K-meta when it tastes right to you.

 

[KCCam]

Sour Grapes seems to be splitting hairs.

I don't think @sour_grapes is splitting hairs here. 23.5° Brix only gets you to 14% ABV or so. That's hardly an ice-wine. 30° Brix gets you up to about 18% ABV. That's quite a difference.

Ice wine is supposed to be sweet, so just kill it off with K-meta when it tastes right to you.

And careful with statements like that. It could get a beginner reading this post into trouble. K-meta doesn't kill yeast. Potassium Sorbate is the key to preventing the fermentation of the residual sugar, but even it doesn't actually kill the yeast. For ice-wine, the sugar and alcohol alone help to prevent re-fermentation, but personally, I would still add sorbate and/or fortify with alcohol to prevent any problems after bottling.

 

[Mead Maker]

I don't think @sour_grapes is splitting hairs here. 23.5° Brix only gets you to 14% ABV or so. That's hardly an ice-wine. 30° Brix gets you up to about 18% ABV. That's quite a difference.


And careful with statements like that. It could get a beginner reading this post into trouble. K-meta doesn't kill yeast. Potassium Sorbate is the key to preventing the fermentation of the residual sugar, but even it doesn't actually kill the yeast. For ice-wine, the sugar and alcohol alone help to prevent re-fermentation, but personally, I would still add sorbate and/or fortify with alcohol to prevent any problems after bottling.

KCCam said 14% ABV is “hardly an ice-wine.”

According to an article on ice wines from Winemaker Magazine, “The levels of alcohol most often fall in the 9 to 11% alcohol by volume (ABV) range.”

I reviewed a number of commercially available ice wines and found that European ice wines are usually in the 8.5% to 10.5% ABV range, while Canadian ice wines seem to have a range from 11% to 14.5% ABV.

Most of the wines I make are in the 18% range. If I were making “high test” ice wine I would first add water until I got to 23.5 Brix, then as the sugars are used up, add more of the juice, DAP and nutrients. I would continue this process until the yeast naturally dies from alcohol poisoning (about 18.5% ABV.

KCCam is correct that Kmeta doesn’t kill yeast, but it would take a lot of space to accurately explain the differences. I’m lazy, so I used “kill” instead of “retard fermentation.”

Sorry.

The only time I ever use Kmeta
or Smeta is to “kill” all the nasties in my must before inoculating with my yeast.

I have chemical hypersensitivity syndrome as an added benefit of one of my cancers, so I try to keep added chemicals to a minimum.

 

[KCCam]

@Mead Maker, I'm terribly sorry. I stand corrected. I'm not an ice-wine drinker. I made an ice-wine-style kit a while ago that came out at 18%. The high-brix juice was fermented dry, then a flavor pack added to back-sweeten. I assumed because of the high sugar content that this high ABV was typical of ice-wine. I was wrong. In Canada, to be called ice-wine the juice must start at 35° Brix, minimum, and the residual sugar must come from the juice itself. At least that's what I'm gathering from the little bit of research I'm doing now. It serves me right for being too quick to say what I think I know to be true, about something I assumed to be true, about something I really don't know that much about. Sorry.

My apologies.

P.S. How come no one else here chimed in to point out my mistake? Huh?

 

[cellardweller]

Thanks for the input. I am going to bring a sample of the juice back to the seller and see what they have to say for their product. I've purchased ice wine juice from them in the past and had great success. I'll see where this goes.