The bottom line benefit of cold soaking?

[NorCal]

This will be my first year of having my must cold soaked for 3 days prior to inoculation. The planned benefits are color and flavor extraction, while getting little tannin extraction. This is consistent with the style of wine that I’m trying to achieve; fruit forward, depth of flavor, smooth finishing wine. I could also see where this would allow pressing at 3-5 brix, when the alcohol is the highest and tannin extraction would also be at the highest.

Cold soaking seems to be a standard process of many wineries, but it seems not too common amongst us home winemakers. Is it too hard to do vs the benefit situation? Has anyone made the same wine with and without cold soak and can speak to the difference?

 

[David Violante]

The first thing that came to mind was @Ajmassa using dry ice to cold soak prior to fermentation. This is a great question~ it would be a pretty interesting experiment to do a cold soak, regular ferment, and extended maceration and see what the differences are.

https://www.winemakingtalk.com/threads/cold-soak-using-dry-ice.72303/

 

[Tim3]

I started cold soaking a few years ago and can say there is a world of difference. The cold soak allows for the water soluble blue pigments to be released and extends skin extraction without extending the alcohol based extraction of seed tannin. I’ve compared with both Cab and Merlot grapes. My result was a deep purple color (nearly opaque), vs primarily red hues that you could read a newspaper through, with increased tannin and mouthfeel but less bitter and longer chain tannin from earlier wines. It’s hard without a glycol chiller but worth the effort in my opinion. Dry ice is the popular method and probably easier, though I end up dropping a bunch of frozen gallon jugs of water to keep the temperature near 50 degrees, switching them out once they’re defrosted. 2 per 20 gallon brute does it for me. Immediately after crush it helps to freeze the must and as it thaws keep the frozen jugs of water in rotation.

 

[balatonwine]

Is it too hard to do

For someone with a cold basement or cellar (not uncommon in many areas in many homes in colder climates), not so much. For someone in California, sans any basement or cellar, it is more problematic.

In fact, even getting fermentation started this late in the year can be difficult for me. Too cold in the cellar. Cold soaking is the "default", if I want it or not.

 

[Jim Welch]

I started cold soaking a few years ago and can say there is a world of difference. The cold soak allows for the water soluble blue pigments to be released and extends skin extraction without extending the alcohol based extraction of seed tannin. I’ve compared with both Cab and Merlot grapes. My result was a deep purple color (nearly opaque), vs primarily red hues that you could read a newspaper through, with increased tannin and mouthfeel but less bitter and longer chain tannin from earlier wines. It’s hard without a glycol chiller but worth the effort in my opinion. Dry ice is the popular method and probably easier, though I end up dropping a bunch of frozen gallon jugs of water to keep the temperature near 50 degrees, switching them out once they’re defrosted. 2 per 20 gallon brute does it for me. Immediately after crush it helps to freeze the must and as it thaws keep the frozen jugs of water in rotation.

I'm wondering if cold soaking would have the same benefit with a kit wine that includes grape skins?

 

[Tim3]

I'm wondering if cold soaking would have the same benefit with a kit wine that includes grape skins?

No there really isn’t any reason for a cold soak with a kit with skins. The color has already been fully extracted and you’re not going to be getting much additional tannin or extraction from the skins. Though you would still have the risk of spoilage if not done correctly.

 

[Jim Welch]

No there really isn’t any reason for a cold soak with a kit with skins. The color has already been fully extracted and you’re not going to be getting much additional tannin or extraction from the skins. Though you would still have the risk of spoilage if not done correctly.

I was thinking that may be the case but wasn’t sure, thank you

 

[Rocktop]

I was thinking about this , after re-reading the epic NorCal thread about closing the gap between home and commercial wines.
It was mentioned about using a deep freeze to cold soak grapes in their primary tubs. The problem is the in-efficient use of space when using round tubs in a square freezer.
My thought was, could you source large food grade heavy plastic to line the inside of a freezer and then use the whole freezer as cold soak tub and then eventual primary? Of course you would need a thermostat interrupt to turn the freezer into a fridge but they are easy to come by. Once cold soak is done , unplug and start to warm for primary ferment.
Could this work?
RT

 

[distancerunner]

What temperature do you aim for when cold soaking?

Do you punch down/agitate the skins during the process?

 

[crushday]

I'm very interested in the benefits of cold soaking. By next fall, I'm planning on developing a refrigerated space for this exact purpose. It won't be a large space but enough for a couple fermentors. I've considered dry ice as an alternative. However, my research on dry ice tells me that not all dry ice is "food grade". Simply putting dry ice in grape must leaves me wondering what I'm adding to the must.

 

[distancerunner]

I collected some one gallon distilled water containers from the local cigar shop. They use distilled water in their humidifiers.

Pulled the labels, cleaned, filled, and froze. I'm putting three into a fifty gallon brute. Temp varies between 48° and 54°F. Rotate in and out of the freezer as needed.

The two things that I wonder about are, one, is it cold enough? And two, how to get the temperature in the high seventies to low eighties during fermentation?

 

[stickman]

A cold soak should be below 50F otherwise cold tolerant yeasts like Kloeckera will start the fermentation. Kloeckera tolerates 70+ ppm SO2 and can produce ethyl acetate (nail polish) or amyl acetate (banana peel) as well as acetic acid. Usually Saccharomyces takes over once the temperature is favorable for the particular strain involved, there are a few that will handle temperatures in the 50's, but many don't do much until the mid 60's, so check the low end tolerance of any selected yeast you intend to use. The risk increases when must sits for extended periods of time between 50F and the preferred temperature of the selected strain.

Using frozen grapes means my wine gets an automatic cold soak, and the color always looks good at the start, but the final color after bulk aging is variable, sometimes there seems to be a benefit, sometimes not. My Sangiovese and Pinot noir both lost significant color by the time they went into the bottle, still enjoyable wine, flavors are good, but the cold soak benefit on color with these particular grapes is questionable.

 

[Chuck E]

Pulled the labels, cleaned, filled, and froze. I'm putting three into a fifty gallon brute. Temp varies between 48° and 54°F. Rotate in and out of the freezer as needed.

How long does it take to thaw the frozen jugs?

 

[Tim3]

I’ve found every 12 hours the frozen jugs need to be pulled and replaced. A punch down and mix is required in between to keep the temperature even throughout. 50 degrees is the goal. If you start to smell off aromas you should inoculate with your desired yeast strain and allow the must to come up in temperature. 3 days is the max I’ve attempted and also seems to be the max I’m able to keep the temperature low without exhausting myself!

 

[distancerunner]

How long does it take to thaw the frozen jugs?

Ten to twelve hours, depending on cellar temperature. A fifty gallon Brute needs three gallons of ice to maintain the temperature. That’s twice a day. An empty freezer a few days in advance is key.

 

[Juniper Hill]

I usually cold soak my vinifera reds for 48 hrs. Seems to help with colour extraction, and probably helps with flavour as well. My hybrid reds have so much colour as it is that that a cold soak isn't required. I use frozen 2l pop bottles which I swap out every 12 hrs - keeps things around 45-50 F.

 

[Nebbiolo020]

This will be my first year of having my must cold soaked for 3 days prior to inoculation. The planned benefits are color and flavor extraction, while getting little tannin extraction. This is consistent with the style of wine that I’m trying to achieve; fruit forward, depth of flavor, smooth finishing wine. I could also see where this would allow pressing at 3-5 brix, when the alcohol is the highest and tannin extraction would also be at the highest.

Cold soaking seems to be a standard process of many wineries, but it seems not too common amongst us home winemakers. Is it too hard to do vs the benefit situation? Has anyone made the same wine with and without cold soak and can speak to the difference?

I cold soaked my Syrah this year for 3 days, best wine I ever made at home. It really helped smooth out the notoriously tannic nature of Syrah and helped with the color. Though I also added scottzyme color pro and opti red.
Use dry ice directly into the must to cool it down

 

[Nebbiolo020]

I'm very interested in the benefits of cold soaking. By next fall, I'm planning on developing a refrigerated space for this exact purpose. It won't be a large space but enough for a couple fermentors. I've considered dry ice as an alternative. However, my research on dry ice tells me that not all dry ice is "food grade". Simply putting dry ice in grape must leaves me wondering what I'm adding to the must.

All dry ice is safe for wine it is just frozen carbon dioxide and that’s all it is. No added chemicals or anything.

 

[SLM]

The two things that I wonder about are, one, is it cold enough? And two, how to get the temperature in the high seventies to low eighties during fermentation?

Is a high temp necessary? I have read here that a slow ferment is good. My ferment room is 66 degrees, must is 71. Seems to be going well so far.

A cold soak should be below 50F

My grapes were in the 30's when I picked them up and my garage was in the mid 50's. I soaked 3 days, high was about 56. Good thing I didn't read about cold tolerant wild yeasts, I would have been nervous!

 

[Nebbiolo020]

Is a high temp necessary? I have read here that a slow ferment is good. My ferment room is 66 degrees, must is 71. Seems to be going well so far.

My grapes were in the 30's when I picked them up and my garage was in the mid 50's. I soaked 3 days, high was about 56. Good thing I didn't read about cold tolerant wild yeasts, I would have been nervous!

What I do to prevent cold tolerant yeasts from doing anything is use a product called Zymaflore Egide from laffort it’s expensive but is a blend of yeasts that colonize the must and do not allow wild microbes to grow and that does not ferment the must it just sort of prevents you from needing any sulfites or your must spoiling or fermenting due to wild microbes.
I would pick some up it’s expensive but keeps well.