Cold stabilization

[rhattin]

One of the many advantages to living through a winter in the Maritimes, Canada (insert sarcasm here) is the ability to cold stabilize wine which has aged either in glass or in small 23 l oak barrels. The average winter night time temp now is about 0 deg F. I would normally cold stabilize for 2 to 3 nights in glass.. how long for the oak barrels, both of which are medium reds - alicante, and carmenere? These are RJS kit wines and have been in barrel for 4 months. Maybe i got the order wrong?

 

[oppyland]

I would think wine would at least partially freeze after 2-3 nights at 0*. Has this not been a problem for you? When I have tried cold stabilization in the Wisconsin winter it went outside for only a few hours.

 

[Ohio Bob]

From a physics standpoint, the same mass of wine in glass versus barrel, would depend on the insulating characteristics of glass versus wood (guessing wood is more insulating?). I’m guessing the wine itself sees nearly the same temperature regardless of vessel.

An issue with a wood barrel is freezing that you can’t see perhaps damaging the barrel. I don’t use barrels so I’m just guessing.

I use a basement refrigerator that I push things around to make room for my 5 gallon carboy. I usually give it 2 weeks and rarely see anything drop out, possibly since it’s pretty clear going in. That might not work for a barrel depending on the size.

 

[Ohio Bob]

I would think wine would at least partially freeze after 2-3 nights at 0*. Has this not been a problem for you? When I have tried cold stabilization in the Wisconsin winter it went outside for only a few hours.

2-3 days in Canada seems too much (I’m afraid the glass carboy might crack).

2-3 hours doesn’t seem like enough time, have you seen sediment/crystals drop out in that short a time? If you check those bottles in a year or two, do they develop any?

 

[tullamore]

One of the many advantages to living through a winter in the Maritimes, Canada (insert sarcasm here) is the ability to cold stabilize wine which has aged either in glass or in small 23 l oak barrels. The average winter night time temp now is about 0 deg F. I would normally cold stabilize for 2 to 3 nights in glass.. how long for the oak barrels, both of which are medium reds - alicante, and carmenere? These are RJS kit wines and have been in barrel for 4 months. Maybe i got the order wrong?

hey my fellow Canuck - your night time temps are better then ours in Ottawa -
are u leaving the carboys outside? in a garage? - 2-3 days is not enough time to cold stabilize
i'm confused when say - how long for oak barrels? are u planning to cold stable in the barrel? if so i would not consider that option - leave your oak barrel for aging

 

[Tin_Man]

I agree with @tullamore, cold stabilizing in a barrel is going to leave tartrates that will be impossible to clean.

 

[Johnd]

Just curious, why are you folks cold stabilizing your wines? Are they too acidic? Worried about diamonds?

 

[distancerunner]

Good question.

Reducing acidity is the number one reason.

Diamonds don't bother me. But I remember the first time I encountered them. Didn't notice them in the pour. Got some in my mouth. Really off putting. I'd prefer to save someone the (potentially bad) experience with the wine I give away.

 

[mainshipfred]

I make a fairly decent amount of wine and have to say I have yet to experience wine diamonds. But then again my wine is aged and stored at the same temperature 55-60.

 

[distancerunner]

I make a fairly decent amount of wine and have to say I have yet to experience wine diamonds. But then again my wine is aged and stored at the same temperature 55-60.

Same here. But once it leaves our cellars it's dollars to doughnuts that it's going to end up in someone's fridge.

 

[oppyland]

2-3 hours doesn’t seem like enough time, have you seen sediment/crystals drop out in that short a time? If you check those bottles in a year or two, do they develop any?

I'm far from an expert on this - I have only tried it to clear a couple batches of pear wine I made a few years ago. The wine is long gone, but I don't recall seeing anything in the bottles.

 

[distancerunner]

The rule of thumb for cold stabilization is 28°F for 72 hours. Warmer and/or shorter duration at temperature means a smaller amount of tartrates will drop out of solution.

Wine freezes at 22°F.

 

[winemaker81]

I make a fairly decent amount of wine and have to say I have yet to experience wine diamonds. But then again my wine is aged and stored at the same temperature 55-60.

I have crystals in 2 wines, and my cellar is 58 F in the winter. The amount of over saturated tartaric acid is the key.

I've never had crystals from kits (acid is balanced) or CA reds (acid is typically low). NY Finger Lakes whites dropped a ton of crystals, and reds did some, as the grapes are typically high in acid.

Wine freezes at 22°F.

No, this is incorrect. The freezing point of wine is variable, depending on the ABV and possibly other constituents. A 10% ABV wine will freeze at 25 F, according to the U of Illinois. I've seen reports of wine freezing as high as 28 F.

Which report is believable? I don't know for sure, so I err on the side of caution. Many moons ago a friend left a case of wine in his back seat overnight, and the wine froze, enough to be solid slush in the bottle, but no broken glass. The wine was nasty tasting.

I do not let wine go below 32 F, and IME any temperature below 40 F is sufficient. When I lived in NY I put carboys on my porch, which was typically 33-38 F in the winter. One to 2 weeks on the porch did the trick.

 

[ChuckD]

Ok so I haven’t seen this question covered.

Once you do cold stabilization and get crystals to settle out can I put the carboy back in the cellar to continue aging or should I wait until I’m ready to bottle to cold stabilize? If I cellar the carboy At 55 to 65 F will the crystals dissolve again?

 

[Bmd2k1]

I'm curious if anyone cold stabilizes their Reds? ....or are you doing it just for whites, Rose' etc

Cheers!

 

[montanarick]

seeding with cream of tartar will help give crystal nucleus to form on. don't forget to rack before wine wamrs back up or crystals will go back into solution

 

[winemaker81]

Once you do cold stabilization and get crystals to settle out can I put the carboy back in the cellar to continue aging or should I wait until I’m ready to bottle to cold stabilize? If I cellar the carboy At 55 to 65 F will the crystals dissolve again?

The primary purpose of cold stabilization is to remove excess tartaric acid. Clarification is a side benefit. When cold stabilizing, rack the wine off the sediment before it warms up. I've read that some of the crystals may dissolve when the wine warms up, but have not tested it as the purpose was to remove excess tartaric acid, so leaving the crystals in didn't make sense.

Once you've cold stabilized, let's say below 50 F (10 C), it's highly unlikely you'll experience crystals dropping at 55 F (13 C).

FYI, crystals can drop at ANY temperature if the saturation threshold for tartaric acid is reached. Realistically it's going to be temps below 60 F (16 C).

When I did it, I cold stabilized as soon as my porch temperature dropped enough -- typically wines started in Sep/Oct were stabilized in Dec (northern hemisphere). If using a different method, I'd cold stabilize after fermentation was complete, as it helps with clearing, and it gives you time to make corrections (if necessary).

I'm curious if anyone cold stabilizes their Reds? ....or are you doing it just for whites, Rose' etc

Any wine can be cold stabilized -- the question is "should I?". If the wine doesn't have excess tartaric, nothing will happen. If the wine is on an acid threshold, too much acid can be precipitated and the wine turns flabby. When living in NY, I cold stabilized only the reds that tasted acidic.

I taste the wine -- if it's not acidic to taste, then "full" cold stabilization is not necessary. By "full" I mean storing the wine below 40 F (4 C) for at least a week.

If dropping crystals in the bottle when it's chilled is the problem, chill the wine to 55 F (13 C) instead of going with a lower temperature. This will precipitate enough to avoid dropping in the bottle, without doing too much. Note that it is still possible to the wine can turn flabby, but less likely.

My winter storage conditions (58 F, 14 C) has been sufficient for all wines except two 2nd run wines that I obviously added too much tartaric to. They didn't taste acidic at bottling time and don't taste flabby now, so other than having to be careful pouring the last glass, it's not a problem IMO,

 

[distancerunner]

No, this is incorrect. The freezing point of wine is variable, depending on the ABV and possibly other constituents. A 10% ABV wine will freeze at 25 F, according to the U of Illinois. I've seen reports of wine freezing as high as 28 F.

Which report is believable? I don't know for sure, so I err on the side of caution. Many moons ago a friend left a case of wine in his back seat overnight, and the wine froze, enough to be solid slush in the bottle, but no broken glass. The wine was nasty tasting.

I do not let wine go below 32 F, and IME any temperature below 40 F is sufficient. When I lived in NY I put carboys on my porch, which was typically 33-38 F in the winter. One to 2 weeks on the porch did the trick.
[/QUOTE]

Good points. Freezing point is alcohol dependent. Most wines are made at 10% ABV or above. So we can agree that 28°F is relatively safe as long as the wine in question is not ridiculously low in alcohol.

As far as 32° F goes, this is something we're wrestling with right now. The results on our carboys that remained at 30° or above was less than stellar. The tartrate precipitation was not compact and variable. I'll test for pH in the next couple of days.

 

[winemaker81]

Good points. Freezing point is alcohol dependent. Most wines are made at 10% ABV or above. So we can agree that 28°F is relatively safe as long as the wine in question is not ridiculously low in alcohol.

My personal risk tolerance is to not push it that closely. However, I agree 28 F should be safe, and if your risk tolerance finds that acceptable, cool.

As far as 32° F goes, this is something we're wrestling with right now. The results on our carboys that remained at 30° or above was less than stellar. The tartrate precipitation was not compact and variable. I'll test for pH in the next couple of days.

My concern is if the temperature control is not rock solid, e.g., in a refrigerator -- a temperature drop of 1 or 2 degrees could be catastrophic if the wine is too close to its freezing point. I did not trust the situation if my porch if the temperature hit freezing, and certainly not below.

If just occurred to me that this colors my perception greatly, and I'd be more risk tolerant if doing it with a refrigerator.

Do you have some of the wine that was not cold stabilized? A taste comparison will tell you a lot.

It's been a long time, but I recall some batches dropping a lot of crystals and others not, and at least one "not" batch was a totally different wine, post stabilization. Like many other areas of winemaking, there are numerous factors in play, not just the amount of tartaric acid. I 'spose you could stabilize 1 gallon batches at 34, 32, 30, and 28 F to see what the differences are.

 

[distancerunner]

Wine that hasn't been through stabilization? I don't know. I'll check tomorrow when we're working again. If we do, we'll taste and report back.

I've wondered about seeding with tartaric crystals. I wonder if it would be faster, cause more precipitate (I'd think that would be governed more by temp), or somehow change the flavors i.e. stripping.