Ice Cider won't stop fermenting

[Rob S]

This is the second time I make an 'Ice' version of wine or cider. Last time I found it hard to stop the fermentation once it had reached the desired residual sugar and acidity and after I followed the directions I found in 'Winemaker Magazine'. This time I'm doing an Ice cider with the same problem.

Both articles are similar and one says to lower the temp to around -4C (25F) and keep it there for a day or so and for the ice wine to add 100 ppm SO2, while for the ice cider 30 ppm. Even at 100 ppm, it kept on fermenting in the fridge once it warmed up from a bit below freezing for a couple of days.

So for the Ice wine I ended up placing it in the chest freezer for over a week at -18C (0F) and it finally did not re-ferment.

For my current ice cider I added 43 ppm SO2 to bring it to 0.8 molecular and put it in the deep freeze -18C for a couple of days, but it started to ferment again.

So wondering what most people do to stop their ice cider\ice wine fermentations? Do I need to put it back at -18C for a week or two and this time add another 47ppm of SO2? If it's using Sorbate, then won't work below 200 ppm, and is the rate that it can be detected and for me would leave an undesired taste.

Thanks,

Rob

 

[user 36973]

When I make apple cider, I chaptalize it to 14brix, let it ferment dry for a few weeks then rack, sweeten it up and add 200ppm sorbate along with sufficient sulfites. It is then filtered through a 1um cartridge filter into kegs where I pressure it up to 30psi with CO2. I don't notice the sorbate over the apple flavors, or it just doesn't bother me. Frankly I was wary that this would be enough to avoid refermentation because of the low ABV and only 200ppm sorbate but it has not been an issue.

You need to be sure to rack the wine off the yeast so it doesn't start to referment when it warms. This would mean carefully racking it off after you've chilled it, while avoiding oxidation. Filtering is the best option but you would need to go with sterile membrane filtering (costly and easily clogged) to be more assured that the yeast has been removed. My 1um filter cartridge is NOT sufficient to remove all the yeast. I have sterile filtered it too in the past.

Perhaps with a good enough racking and settling scheme, you could reduce the necessary amount of sorbate you use below your taste threshold, but I have no confidence you can get a sweet, unfiltered wine that doesn't referment without sorbate.

 

[Rob S]

Thanks. Might reconsider trying sorbate and upping the SO2. I pressed frozen apples at 18F and fermented starting at 32 Brix. It took about 3 weeks to get to where I want it now at 14 Brix with TA of 14.7, alcohol estimated around 9.5%. If it goes beyond I would back sweeten, but slowly fermenting in the fridge so still have time to decide. Over the next few days will have to act on it.

I would degass and then rack off sediment, then clear it using Kieselsol and Chitosan. This worked with the ice wine that has been in the cellar for over a year now and never re-fermented. However needed 100 ppm of SO2 and the deep freeze for over a week. Turned out good, did not oxydize.

Rob

 

[Scooter68]

Most folks with a lot of experience will tell you:
1)It's very hard to stop a fermentation in process. Even if you succeed stopping it at the target ABV is hard.
2) It's much better to start at a point where a finished fermentation gives you the desired ABV.

Your experience so far seems to support those ideas.

 

[Rob S]

Thanks both of you for your help. Agree on how hard it is to stop it mid way like this. Usually a fermentation will stop once the level of alcohol becomes too toxic for the yeast and very little sugar left over. But when making ice wine or ice cider the 'style' is to have lots of sugar left over and finishing at a level that has less alcohol than a finished wine. An icewine comes in around 9%-12% ABV and starting Brix around 32-35 so that always means there will be approx 12-15% sugar left near the end when it struggles to still ferment, but is hard to stop it. Unless one starts at a lower brix and ferments to dryness and then backsweets to 14%, but that is not really the way to be making icewine or ice cider. Some wineries will sterile filter, but most hobbyists are not equiped to do this, means filters less than 1 micron, expensive system. Thinking like jgmillr1 said, will look at combination of racking, settling, chilling, so2, and perhaps sorbate.

Cheers,

Rob

 

[Scooter68]

Sounds like a plan.

 

[ThreeSheetsToTheWind]

I have no confidence you can get a sweet, unfiltered wine that doesn't referment without sorbate.

Just throwing this out there but I have successfully bottle carbed and stopped fermentation by pasteurizing the bottles in a stockpot on my stove, leaving exactly the amount of sweetness I wanted. No sorbate, no filtering, no refermentation, no discernable difference in flavor compared to unpasteurized.

I did however get a slight dusting in the bottles, which is unavoidable when bottle carbing.

I plan on using the method for cider this fall.