Cold soak using dry ice

[Ajmassa]

Anyone know if attempting a cold soak using dry ice is realistic? Never heard of anyone doing this before (only for transport), however maybe that’s for a good reason.

~30gal of must. Figured I’d separate into 5gal buckets. Building a little makeshift insulated box, dumping AC into it with flex duct maybe too. I read dry ice wrapped in newspaper can last multiple days in a Yeti cooler. Was thinking a 3 day soak.

Or would this require entirely too much ice to maintain temps?
And is all that co2 going to have any negative effects? (If anything I assume co2 only helps me here)

Other option is to try and finagle a deal with the liquor store owner up the street for a few days of refrigerator space. I’m trying to get the most out of my grapes this year. Doing a little sagneé likely. Frozen jugs later in the ferment. But I think a nice legit cold soak could be a huge benefit. Hard to get even a week of skins time otherwise.

 

[Rice_Guy]

Dry Ice will absorb 270 BTU per pound. To say this another way twenty pounds of dry ice would generate as much cooling as a 5000 BTU air conditioner over one hour, ,,, however if you wanted to cool for a second hour you would want another twenty pounds of dry ice.

Conclusion dry ice is not as practical as a small air conditioner.

 

[Ajmassa]

Dry Ice will absorb 270 BTU per pound. To say this another way twenty pounds of dry ice would generate as much cooling as a 5000 BTU air conditioner over one hour, ,,, however if you wanted to cool for a second hour you would want another twenty pounds of dry ice.

Conclusion dry ice is not as practical as a small air conditioner.

Thank you. I knew you’d have some insight for me regarding the specifics. But let me ask you another question.
Let’s say those 6 buckets were wrapped with insulation sleeves and resting within a little box made of 2” thick insulation boards on all sides. That 20lb 1hour 5000btu equivalent of dry ice could last a bit before another round of ice is needed.
In your professional opinion do you think I would be able to maintain at least 50° with additions every few hours located in a temp controlled ~69° basement?

thinking the liquor store fridge might be my best bet

 

[Rice_Guy]

* Dry Ice is concentrated CO2 you have a safety issue in the basement, ,,,this is used to humanely put hogs to sleep before they are converted into meat. The concept would be significantly safer done in the garage with the garage door cracked open, or outside.
* Dry Ice will turn from gas to liquid at -109F therefore it is excellent for keeping things frozen. It will have a tendency to pull heat/ release cold into the insulation box till it gets to minus 109. The energy from freezing is a heat sink (wall or barrier) so it will probably get to 32F when freezing on the bucket surface has started and then the mass would hang there. Did you have a temperature in mind?
* this is a fun project I would be likely to try, my approach would be to pull a metal shelf out to put the buckets on, remove the door from the fridge and then tape insulation to the front of the fridge to create the box ,,, OR cool everything in the walk-in fridge pull them home and place them in a cardboard box (weak insulation) which is enclosed by the 2” board on all sides. A small entry should be on the top so you can add dry ice if needed. The heat load for maintaining temp is minimal and most of the heat load will be in the initial cooling to freezing point.

Thank you. I knew you’d have some insight for me regarding the specifics. But let me ask you another question.
Let’s say those 6 buckets were wrapped with insulation sleeves and resting within a little box made of 2” thick insulation boards on all sides. That 20lb 1hour 5000btu equivalent of dry ice could last a bit before another round of ice is needed.
In your professional opinion do you think I would be able to maintain at least 50° with additions every few hours located in a temp controlled ~69° basement?

thinking the liquor store fridge might be my best bet

,,, the walk-in isn’t as much fun, ,,, what temp did you want to run?
to cool water from 82 to 32 is 50 BTU per pound therefore cooling five buckets is 12,500 BTU and it would take 46 pounds of dry ice to do the initial cooling and what outside air temp did you want to design for for maintaining temp? ought to ask how much per pound dry ice is where you are? Renting chest freezer with a temperature controller would be another neat way since the box shape is there.

 

[Johnd]

Anyone know if attempting a cold soak using dry ice is realistic? Never heard of anyone doing this before (only for transport), however maybe that’s for a good reason.

~30gal of must. Figured I’d separate into 5gal buckets. Building a little makeshift insulated box, dumping AC into it with flex duct maybe too. I read dry ice wrapped in newspaper can last multiple days in a Yeti cooler. Was thinking a 3 day soak.

Or would this require entirely too much ice to maintain temps?
And is all that co2 going to have any negative effects? (If anything I assume co2 only helps me here)

Other option is to try and finagle a deal with the liquor store owner up the street for a few days of refrigerator space. I’m trying to get the most out of my grapes this year. Doing a little sagneé likely. Frozen jugs later in the ferment. But I think a nice legit cold soak could be a huge benefit. Hard to get even a week of skins time otherwise.

Short of the commercial walkins that we beg our way into, next best bet is probably a large chest freezer or fridge. Dedicated to the mission with an Inkbired temp controller, you should be able to maintain any temp you like, indefinitely.

 

[Jay A]

AJ, I attempted this years ago when I first heard of cold soaking. Vendor wouldn't sell me dry ice until I came back with a pick up truck! Consider a well ventilated garage.

I have 2 vats that hold 15-20 lugs, but they are not insulated. I considered getting the exterior spray foamed & should have because the soak was very short lived.

I think it got me a couple of extra days before innoculating? I'll check notes tonite. Didn't feel outcome changed much.

good luck

 

[Ajmassa]

* this is a fun project I would be likely to try, my approach would be to pull a metal shelf out to put the buckets on, remove the door from the fridge and then tape insulation to the front of the fridge to create the box ,,, OR cool everything in the walk-in fridge pull them home and place them in a cardboard box (weak insulation) which is enclosed by the 2” board on all sides. A small entry should be on the top so you can add dry ice if needed. The heat load for maintaining temp is minimal and most of the heat load will be in the initial cooling to freezing point.

,,, the walk-in isn’t as much fun, ,,, what temp did you want to run?
to cool water from 82 to 32 is 50 BTU per pound therefore cooling five buckets is 12,500 BTU and it would take 46 pounds of dry ice to do the initial cooling and what outside air temp did you want to design for for maintaining temp? ought to ask how much per pound dry ice is where you are? Renting chest freezer with a temperature controller would be another neat way since the box shape is there.

My goal is not to freeze but only to maintain. At time of pickup the grapes will be cold, likely 32°-40°. I cover with a heavy duty moving blanket into the pickup truck bed lined with insulation boards on all sides for the 1 hour drive home. By the time grapes are crushed they’re likely sitting at about 50°-55°.

That initial ‘heat load’ would be minimal since I’m shooting for <50°. Just cold enough to delay fermentation for extra maceration time.

Locally I can get dry ice 25lbs for $50. 45lbs for $70. And I do have a 7cu.ft. chest freezer that could fit x2 6gal buckets unless I find a container appropriately sized to utilize more of that 7cu.ft. freezer. Then rotating vessels from the DIY dry ice box to the chest freezer to maintain <50° for a few days.
Just spitballing ideas here. I’ve got a few weeks to prepare

 

[Ajmassa]

AJ, I attempted this years ago when I first heard of cold soaking. Vendor wouldn't sell me dry ice until I came back with a pick up truck! Consider a well ventilated garage.



I have 2 vats that hold 15-20 lugs, but they are not insulated. I considered getting the exterior spray foamed & should have because the soak was very short lived.



I think it got me a couple of extra days before innoculating? I'll check notes tonite. Didn't feel outcome changed much.



good luck

few days better than no days! That’s substantially more volume than I’d be working with so I could imagine the amount of ice needed to chill those large vats in a non temp controlled garage was quit a bit. But even though you were spitting in the wind so to speak, you still managed to get a couple days. So somewhat successful attempt. Whether the wine benefitted or not is another story.

I’m definitely going to attempt soaking this must, just not exactly sure how yet Nice of the vendor to not want you to pass out on your drive home lol.

But how do you know if there was benefit or not? Did you make the same grapes previously to have comparison?

 

[Ajmassa]

Short of the commercial walkins that we beg our way into, next best bet is probably a large chest freezer or fridge. Dedicated to the mission with an Inkbired temp controller, you should be able to maintain any temp you like, indefinitely.

I do have a chest freezer I’ll likely utilize. Just can’t fit it all in there at the same time. Not dedicated to the mission unfortunately. But will certainly help the cause. Still playing around with different ideas right now.

you know the deal. Running standard fermentation with no temp control I’m dry after 5-6 days of active fermentation if I’m lucky. normally crush on Saturday. Yeast on Sunday. Press on Saturday. love to get extra days of skins time. I sprung for Napa grapes (Rutherford Bench) and I want to make the best possible wine I can make.

 

[Snafflebit]

Is your must too warm because of fermentation or because you are keeping it in a warm location?

I am cooling 20 gal of must by putting 1 frozen milk jug in it per day. This drops the temp from 72F down to 66F.
My must is inside a conditioned space. This is not a perfect system but it is simple

 

[porkchopmessiah]

For what it's worth, my 54 liter demijohns fit in my fridge with the shelves removed....got last springs merlot blend in there trying to get all the neutralized Crystal's from adding potassium bicarbonate to drop out

 

[Ajmassa]

Is your must too warm because of fermentation or because you are keeping it in a warm location?

I am cooling 20 gal of must by putting 1 frozen milk jug in it per day. This drops the temp from 72F down to 66F.
My must is inside a conditioned space. This is not a perfect system but it is simple

I haven’t attempted to cool down active fermentation yet. I got nervous the jug would break open. But I do plan on going thru with it this time. And your data of how 1 jug alters 20gal is extremely helpful. hoping this technique could gain a day or 2.

I was specifically talking about cold soaking before fermentation though. To delay as many days as I could. 3-5 preferably. Figured to do this I need to keep it around 50°. My ultimate goal is 2 weeks from crush till press.

 

[Ajmassa]

For what it's worth, my 54 liter demijohns fit in my fridge with the shelves removed....got last springs merlot blend in there trying to get all the neutralized Crystal's from adding potassium bicarbonate to drop out

Surprised that fit! No extra fridge over here tho. When I cold stabilize I rack to carboys and stick in the shed for a few weeks. I made insulation jackets for them and each go in a milk crate.

However keeping 30gal of must chilled for an extended period is new territory for me.
I have some Tupperware containers that I could modify and fit maybe all the must into the freezer. might work.

Maybe I’m putting too much emphasis on skins time idk. But I do know the pros get more than a week and I’m gonna give it the ol college try.

 

[Rice_Guy]

However keeping 30gal of must chilled for an extended period is new territory for me.
I have some Tupperware containers that I could modify and fit maybe all the must into the freezer. might work.

you have other shapes that get away from round which is inefficient, cubitainer as from the camping store, 30 gallon PE drums, rectangular poly totes, a fiber drum with a simple polyethylene liner, and even plywood box with a polyethylene liner.

 

[KCCam]

It will have a tendency to pull heat/ release cold into the insulation box till it gets to minus 109.

@Rice_Guy has a lot of excellent points in his post. Personally, I believe the biggest issue is temperature control. As he says, as long as there is solid CO2, it will be "trying" to bring everything around it down to its temperature, which will be something less than -109°F. If you don't have some way to control it, manually or otherwise, your must will eventually freeze, assuming you have a large enough quantity of dry ice, and your insulation is good enough.

There are 2 separate problems here. The first is dropping your must to the desired temperature, the second is keeping it there.

1. As already mentioned, dry ice has a given heat capacity at a given temperature, meaning that it will take a specific amount of energy to transform a pound of dry ice from its initial temperature into a gas, at say 50°F. That happens in 3 stages, which happen somewhat simultaneously: warm the solid from its starting temperature to -109°F, sublime ("evaporate") the solid into a gas, at -109°F, then warm the gas to 50°F. It depends on the initial temperature of the dry ice, but 270 BTU per pound sounds right. As Rice_Guy said, assuming your must has the same heat capacity as water, cooling 30 gallons by 50°F would take about 12,500 BTU, or about 46 lbs of dry ice. To go from 55°F to 50°F would be 1/10 of that, or 4.6 lbs. Keep in mind it takes time, because this mode of heat transfer is relatively inefficient.
2. The second problem is keeping the temperature constant. The cooling required will be related to the mass of your must, the R-rating of your insulation, the temperature difference between the inside and the outside of the insulated box. and how well sealed the box is (vapour barrier). Two methods of control you have that come to mind are: adding and removing the dry ice to cycle the temperature around 50°F (or adding controlled amounts at proper time intervals), and varying the amount of insulation around the dry ice within your box. Preferably you have a remote temperature sensor to monitor your must without having to open the box. Too much insulation around the dry ice, and your must gets warmer, too little, and your must gets colder.

 

[KCCam]

* Dry Ice is concentrated CO2 you have a safety issue in the basement, ,,,this is used to humanely put hogs to sleep before they are converted into meat.

Hahaha, I thought you said "to humanely put dogs to sleep before..." I mean, I figured it was just tongue-in-cheek, but without the obligatory "LOL" or winky face, I was starting to wonder... Glad I read that again!

 

[Jay A]

My Grape of choice is Lanza Sangiovese. Always used enzymes, my goal was to get some extra color out of the skins. I saw no difference in color or taste for that matter. Now I add some decent Alicante to add color.

The grapes froze on contact with dry ice, obviously not the whole vat, large basketball sized chunks. I. did get concerned about the dry ice cracking plastic vat & wasting all that must. Fortunately that didn't happen. The 5 gallon buckets in a large cooler is a good plan.

I've used frozen plastic juice bottles as ice bombs in the past. Never able to get temps down, only maintain. This year I'm gonna try & get creative with a chiller.

In addition to my sangiovese,, last year I sprung for 5 cases of $ Washington Cabernet Sauvingon. It was my 1st experience with a "Brute" container due to small volume. Much like yourself a week after crushing I'm usually pressing. I followed the same protocols as always, the cab took 2 weeks to get down to pressing gravity. Temp cruised along @ 76* rock steady. I'm pretty sure my large vats contribute to the higher temps generated while fermenting. Hope this helps.

 

[Ajmassa]

@Jay A I’m sure some grapes only have limited color to extract no matter the amount enzymes or time on skins. Sangiovese probably a tough one to do successfully. When I did a sangio I was surprised to see how much lighter it was compared to others. Also had a extra light cab in ‘18.
Your cab goin 14 days is awesome though. You remember what yeast was used? I’ve been using Avante. Probably the one and only negative is how fast it runs dry. How’s that cab. Tasting a year later?

 

[Ajmassa]

@KCCam and @Rice_Guy - lots of useful information said above and it’s much appreciated. I’ve got a good bit to contemplate here
I’m looking at 3 options at this point.

1. Dry ice additions to Buckets of must stored in an insulation chamber
2. Modify chest freezer to hold 30gal of must
3. Rent some walk-in fridge space at a local business

I’m not overly concerned with temp fluctuations tbh. As long as I can maintain >55° I don’t think it will make a difference. Remember the ultimate goal is just to buy some time. Even if it froze I’d be cool with that because the thawing time would give me the cold soak I’m looking for as well.

 

[CDrew]

@Jay A I’m sure some grapes only have limited color to extract no matter the amount enzymes or time on skins. Sangiovese probably a tough one to do successfully. When I did a sangio I was surprised to see how much lighter it was compared to others. Also had a extra light cab in ‘18.
Your cab goin 14 days is awesome though. You remember what yeast was used? I’ve been using Avante. Probably the one and only negative is how fast it runs dry. How’s that cab. Tasting a year later?

Good commentary! Personal experience-started 300 pounds of Sangiovese on Sunday, parallel to 350 pounds of Syrah. Enzymes in both. The syrah is like ink. THe Sangio at first was just lightly pink. It's coming around though after 2 days of fermentation. It still won't be a dark wine. But in future years, I think the Sangio might make a nice Rosé.

Regarding Avante speed-Pitched Sunday night, Cap Monday morning. Between Pitching and Tuesday morning (today) it's already dropped from 25 to 15 Brix. I'm thinking press by Friday. It moves so fast, that I wanted to do feeding #2 at 18 brix, but it was already 15 brix when I measured at 0630 today. Pretty cool.

Avante is a great workhorse yeast. I'm still waiting to find a problem with it, but so far, it's a no-brainer.