Cold Crash Wine Gone Wrong. Retrying again. Long read.

[jkim888]

Hello Folks,

I'm new here. I'm still quite an amature home wine maker. But I can say I have experience with making dry reds and whites. Last month, I had a pail of frozen juice from an online vendor, a Muscat to make Moscato. I wanted to make a Moscato with 5-6% ABV with high sugar. Which at 1.060 gravity( starting was 1.103), I cold crashed in my fermentation cooling chamber, which took about 8 hours to get the must from 55f to 32f. I'll tell you how it went. It was a mess, even at that temp it was still fermenting ever so slowly, even with an addition of kmbs during the cold crash. H2S smell started coming strong after a day (used DV10 Lalvin). Since it was still fermenting, the yeast would not settle down in the cold crash, even after using Chitosan/Kiesol. (It's not a pectin Haze, used pectin enzyme)

1. Probably didnt cool it down fast enough to shock it. Thus causing the yeast to stress, survive temp, and poop out H2S
2. Probably used the wrong yeast for a sweet wine like this in terms of temperature tolerance.
3. Probably shouldnt have added goferm and nutrients to make it yeast stronger.

This is my first time cold crashing to stop a fermentation. Learned a lot. I understand cold crashing after 1.030 is much more preferable since there are less sugar and higher alcohol, making it easier to cold crash. But no matter what I search, I can find nothing for a low ABV/High sugar wine cold crash.

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As of today, a month later I have now mustered the courage to redo this. Because I want to be able to do this technique right, and is how normally many Moscato's are made in Italy(Low ABV, High Sugar).
I bought the same pail of the frozen Muscat juice to try this again.

Here are my changes:

1. Renaissance Fresco Yeast - Not capable of producing H2S!! Has a tolerance of 55F.
2. Will not use Go Ferm. As for nutrient, maybe just a very little of Fermaid K or DAP to get it started at inoculation. Goal is not to have such a strong ferment.
3. Once around 5%, I'll cold crash by putting my bucket of wine into another bucket filled with ice(maybe with a little bit of dry ice). Hoping this will get the temp down within the hour than over 10 hours. Once cooled, then into the fermentation fridge.

All I want is for the cold racking to actually stop fermentation, and settle.
Just a note - I am not worried about restarting fermentation in the bottle. I have a .45 micron absolute filter to sterilize, and will be using sorbate/kmbs after filtering. Highly unlikely to pop bottles.

If you got this far, thank you for reading. My question for everyone else here is - What do you think? Anything Should I consider? Similar experience?

 

[ChuckD]

I’ve never tried stopping an active fermentation, but I have read many comments on this site recommending against even trying. Is there a reason you don’t want to let it ferment dry and back sweeten?

 

[jkim888]

I’ve never tried stopping an active fermentation, but I have read many comments on this site recommending against even trying. Is there a reason you don’t want to let it ferment dry and back sweeten?

Just because my partner doesn't enjoy any wine over 8%ABV, disgusts ate the taste. With all this wine I have above 12% I wish to make one where it's low, and her favorite, a moscato. Although I've heard, and know that folks are against it. But it is a possible way to be done(albeit challenging and high risk). I'm wondering from any pro's out there that may provide some insight on how to put this wine into my favor as it does mean a lot to me.

 

[Gilmango]

Just because my partner doesn't enjoy any wine over 8%ABV, disgusts ate the taste. With all this wine I have above 12% I wish to make one where it's low, and her favorite, a moscato. Although I've heard, and know that folks are against it. But it is a possible way to be done(albeit challenging and high risk). I'm wondering from any pro's out there that may provide some insight on how to put this wine into my favor as it does mean a lot to me.

A dinner party guest just brought over a Sourgal Moscato which was quite good and low ABV/high sugar (also frizzante but not too bubbly). I swear that is not the style of wine I like to drink and certainly not to make but it was quite good. So I applaud your efforts but cannot offer up much advice.

Nevertheless, while I doubt that there are any wine yeasts which poop out before 8%, but their might be a beer yeast which does just that. And using one of those along with the rest of your protocol could help.

 

[Johnd]

How about filtering your wine when you hit your desired ABV? Sure, you’ll have to run it through a progression of filters to get to sterile filtering, but it can’t be that bad. Hit it with your chems and move along.

 

[winemaker81]

Another idea -- divide the batch in half and refrigerate one part. Ferment the other part to completion, stabilize it, and backsweeten with the reserved juice. Clear as usual.

 

[Cap Puncher]

3. Once around 5%, I'll cold crash by putting my bucket of wine into another bucket filled with ice(maybe with a little bit of dry ice). Hoping this will get the temp down within the hour than over 10 hours. Once cooled, then into the fermentation fridge.

All I want is for the cold racking to actually stop fermentation, and settle.
Just a note - I am not worried about restarting fermentation in the bottle. I have a .45 micron absolute filter to sterilize, and will be using sorbate/kmbs after filtering. Highly unlikely to pop bottles.

If you got this far, thank you for reading. My question for everyone else here is - What do you think? Anything Should I consider? Similar experience?

I have done a few cold crashes on rose prior in small batches. I'll give you my 2 cents:
1. Don't ferment in a bucket. I would ferment in a carboy. The glass won't hold fermentation heat like the plastic does. Ferment as cold as possible at the beginning I think Fresco cold tolerance is 13C (55.4 F)( you might be able to go even a bit lower)
2. Use the bucket that you plan to fill with ice, add some salt and water (You can get the temp down into the 20s F then)
3. Convection is you friend. Spin the carboy in the bucket with ice water/salt. This will create convection that will drop the temp even faster to the wine inside the carboy. I usually spin it slowly for 15 min or so, then every so often after that. I keep it in the bucket of ice water for a couple hours at least.
4. After, put in your cooling chamber

The rest of you plan seems very good. I typically let is calm down a couple days before sulfiting or sorbating, then I use Chitosan/Kiesol while still cold (I use an old dorm fridge that I converted to a cold stabilization fridge for carboys that can get down to ~25F). It's nice you have the sterile filter set up (you could probably avoid sorbate altogether).

I have successfully done 2 cold crashes using this technique. I stopped one at SG 1.012, the other stopped at SG 1.018. Stopping the SG is the heart of fermentation may prove to be difficult.

Good luck! Let us know what happens

 

[Bmd2k1]

I successfully crash some of my hard ciders at SG 1.02-1.03 --- done using D47 --- just by putting the 20L Speidel into my basement fridge that gets down to 28-32F. Maybe the yeast you select can play into a successful crash.

Good luck.

Cheers!

 

[jkim888]

I have done a few cold crashes on rose prior in small batches. I'll give you my 2 cents:
1. Don't ferment in a bucket. I would ferment in a carboy. The glass won't hold fermentation heat like the plastic does. Ferment as cold as possible at the beginning I think Fresco cold tolerance is 13C (55.4 F)( you might be able to go even a bit lower)
2. Use the bucket that you plan to fill with ice, add some salt and water (You can get the temp down into the 20s F then)
3. Convection is you friend. Spin the carboy in the bucket with ice water/salt. This will create convection that will drop the temp even faster to the wine inside the carboy. I usually spin it slowly for 15 min or so, then every so often after that. I keep it in the bucket of ice water for a couple hours at least.
4. After, put in your cooling chamber

The rest of you plan seems very good. I typically let is calm down a couple days before sulfiting or sorbating, then I use Chitosan/Kiesol while still cold (I use an old dorm fridge that I converted to a cold stabilization fridge for carboys that can get down to ~25F). It's nice you have the sterile filter set up (you could probably avoid sorbate altogether).

I have successfully done 2 cold crashes using this technique. I stopped one at SG 1.012, the other stopped at SG 1.018. Stopping the SG is the heart of fermentation may prove to be difficult.

Good luck! Let us know what happens

Hi Cap Puncher,

Thanks for the detailed notations. Sorry I forgot I had posted this post and finally came around it today. I have started my new batch a week ago. Last night it hit around 4.5% so I did pretty much the same steps as you have. Over the course of 24 hours the gravity of the wine has not changed at all and is the same from before cold crashing. The only issue i'm at right now, which I have experienced before is that there is about 2mm of wine clearing from the top, which I feel is that cold crashing is not helping with clearing. From my previous failed experience adding Chitosan and Kiesol did not help much with the clearing. I'm gonna let this sit for another 1 or 2 days to see if it'll finally start clearing, if not I'll be adding Chito/Kiesol.
I will keep you posted.

But i'm happy to say that, without adding any Goferm and minimal amount of nutrients in the beginning, helped in creating a zero foaming/slow fermentation. Based on my hydrometer reading without any changes, there seems to be zero to maybe the slowest ferment going on. No H2S smell as well.

My question for you is, since the wine is very carbonated since we dont degas at this stage. Have you come across this clearing issue? Wine is reading a temp of 29F.