Timing cold stabilization.

[distancerunner]

Reading Daniel Pambianchi’s book. He recommends cold stabilizing after bulk aging. This idea flies in the face of everything I’ve ever read or done. To the point, crush, ferment, rack, cold stabilize, rack, bulk age.

What is the rationale for holding stabilization until after bulking? Does anyone else recommend this protocol?

 

[Rice_Guy]

I would do cold stabilization in winter in my garage since that is what I have for low temp. Cold removes tartrates and does not apply to country wines. This might be on a six month old wine from spring juice or a few months old from fall juice.

interpreting your time line; crushing could be cold as in ice wine but basically do what is convenient > fermenting is done for the health of the yeast/ generally 50 to 25F > racking off gross lees is done roughly a month after the yeast finishes fermenting, the purpose is to remove juice solids and dead yeast > cold stabilize is for removing excess acid (TA) and goes along with the technique of MLF BUT MLF only grows at temperatures above 50F. Factory wine sometimes doesn’t finish MLF till spring when the winery warms up. > bulk aging is any tank storage of the wine. It produces uniformity in the batch.

Practically speaking it is nice to cold stabilize after the fermentation is done but unless you have temperature controlled tanks you just do it in winter.

 

[winemaker81]

Why does Pambianchi say to cold stabilize?

Generally speaking, cold stabilization is performed to reduce excess acidity and to avoid the formation of tartrate crystals in the wine as it ages. If the wine doesn't have excess tartaric acid (which precipitates as potassium bitartrate), there will be no change. If the wine tastes fine, then cold stabilization may reduce the acidity too much, rendering it flabby.

Note that full cold stabilization is reducing the wine temperature below 40 F (4.5 C) for a period of time, with closer to freezing being most effective. If you have an overly acidic white, this action may be beneficial and has less side effects than chemically reducing acid.

OTOH, chilling the wine to 50 F (10 C) to 60 F (15.5 C) may precipitate some crystals, which prevents them from forming in the bottle. This doesn't reduce the acid as much, but more may not be necessary, or even advisable.

As with every other action in winemaking, ask yourself the question, "What am I gaining from this?"

 

[distancerunner]

The OP is edited. It now reads, "...recommends cold stabilizing after bulk aging."

Everyone I learned from recommends cold stabilizing before bulk storage. Where I live that means that usually MLF is complete before the wine goes outside to stabilize and drop excess tartrate.

I posted the question on Pambianchi's FB group. This is his reply:

"If you are asking why cold stabilize after aging and for reds specifically, well, there are different ways to do it, and I only illustrated a typical protocol, the one I use. You can certainly cold stabilize and then bulk age if you don't expect the chemistry of the wine to change. But it's always safer to cold stabilize as the very last step before pre-bottling operations. For example, if you cold stabilize and you bulk age, your phenolic content (mainly tannins) can drop, especially if you decide to do an egg-white fining if you need to tame tannins, and since these act as protective colloids, they can alter the wine's tartrate stability.

But if you read carefully, you'll see that I state that red wine should be cold stable to cellar temperature after bulk aging if it was held at cellar temperature, usually 55F. Red wine is not served or stored any colder, so there is no need to go colder. But if you are a commercial winery, you need to remove that risk, so you would cold stabilize even colder - recommended around 40F. If you read further, I recommend a cold treatment IF the wine seems to have high acidity. This can happen depending on what happened with tannins during bulk aging. If you ended up extracting too much tannins during bulk aging, this will increase the perception of acidity and tannins will taste harsh."

 

[winemaker81]

Thanks for the update. That makes far more sense.

 

[wood1954]

I just brought my Marquette wine back inside after a week of freezing temperatures . Dropped a lot of acid, tastes much smoother now. My wine room stays in the low 50s all winter so it might drop some more. I think you should cold stabilize as soon as you can, then let the wine sit till spring and rack again, let it sit again till fall and bottle just before harvest.
trying to figure out how to get my 10 gallon barrels outside.

 

[winemaker81]

trying to figure out how to get my 10 gallon barrels outside.

several friends and a dolly?

If you have a couple of extra 19 liter carboys, rack a barrel into 2 carboys, cold stabilize, and rack back into the barrel. You'll need a holding solution for the week of CS, but it sounds like it's worth it.

 

[wood1954]

several friends and a dolly?

If you have a couple of extra 19 liter carboys, rack a barrel into 2 carboys, cold stabilize, and rack back into the barrel. You'll need a holding solution for the week of CS, but it sounds like it's worth it.

Unfortunately all my carboys are full. I suppose after two years the excess acid will drop out.

 

[elieenk]

Reading Daniel Pambianchi’s book. He recommends cold stabilizing after bulk aging. This idea flies in the face of everything I’ve ever read or done. To the point, crush, ferment, rack, cold stabilize, rack, bulk age.

What is the rationale for holding stabilization until after bulking? Does anyone else recommend this protocol?

When you cold stabilize after bulk aging you are getting rid of a large amount of dissolved oxygen in wine which allows the wine to age much slower. In fact, you can allow a wine to age as long as you wish, even 20+ years, as there will not be much oxidation. If we were to analyze a wine’s makeup after cold stabilization, we’d find much lower free sulfur levels, less volatile acidity, lower pH, and if you taste the wine it would be basically undrinkable. However, if the wine were to be put in the bottle at this point and aged, the wine is protected from any further oxidation and the sulfites which were added to the wine during cold stabilization effectively make the wine stable (and the wine thus able to be aged indefinitely) and the wine will not oxidize. I don’t know of anyone else who does this, but I have never seen any literature against it and I’ve done it for years now without any problems.

 

[winemaker81]

I suppose after two years the excess acid will drop out.

Not necessarily. The cold lowers the saturation point for tartaric acid, which is why excess forms crystals and precipitates. You'd probably get crystals in the bottles, but the acid won't be reduced to the level you'd achieve if the wine is stabilized at 32-37 F (0-3 C).

 

[wood1954]

Actually it’s very complicated, depending on the chemistry of the wine the ph can go up or down after cold stabilization. Not sure why VA would go down or oxygen. With Marquette I always get a good layer of acid in the bottom of the carboy after a year at cellar temp , my barrels are on wheels so maybe I can make a ramp .

 

[wineview]

I just brought my Marquette wine back inside after a week of freezing temperatures . Dropped a lot of acid, tastes much smoother now. My wine room stays in the low 50s all winter so it might drop some more. I think you should cold stabilize as soon as you can, then let the wine sit till spring and rack again, let it sit again till fall and bottle just before harvest.
trying to figure out how to get my 10 gallon barrels outside.

How long did you leave the wine outside? Do you need to rack before it warms up to yield the benefits?

 

[winemaker81]

How long did you leave the wine outside? Do you need to rack before it warms up to yield the benefits?

I was taught to rack the wine before it warmed up. However, I've read that the crystals won't dissolve easily upon warming. I don't know which to believe, so unless someone provides evidence that it's not necessary, I'd go low risk and rack the wine while cold.

 

[distancerunner]

I was taught to rack the wine before it warmed up. However, I've read that the crystals won't dissolve easily upon warming. I don't know which to believe, so unless someone provides evidence that it's not necessary, I'd go low risk and rack the wine while cold.

Anecdotal evidence only.

I've done it outside in thirty degree weather. I've brought it in and let it warm up into the fifties. Whatever is on the bottom of the carboy is pretty much locked in by the tartrate crystals. The crystals do not appear to go back into solution.

I've run pH tests before and after. Post rack = pre-rack.

It's warmer in the cellar.

 

[CDrew]

I live in an area that never gets that cold. But, the last week my 2022 wines in the garage have gone to the mid 40s. It is bulk aging at that temperature. I'm hoping that is enough to drop what is going to drop. I'm leaving the wine in the garage until until February so it could get colder but we are likely near the seasonal low now. Most of the wineries in the area do the same.

So that's all the cold stabilization I'm going to get. I do not know what is best or perfect, but it's what I have. This year in particular, my idea is to leave it in the (unheated) garage until spring. It might get to upper 30s and that's fine. One of the local winemakers I really like, feels the seasonal temperature variations are important in the development of the wine. Not sure that's true, but I'm going with it. In an ideal world, I'd have a 57F basement, but not happening here.

And, the crystals once formed, do not redissolve. So if you manage to cold stabilize, rack at your convenience.

 

[wood1954]

How long did you leave the wine outside? Do you need to rack before it warms up to yield the benefits?

I left it outside for a week

 

[distancerunner]

I live in an area that never gets that cold. But, the last week my 2022 wines in the garage have gone to the mid 40s. It is bulk aging at that temperature. I'm hoping that is enough to drop what is going to drop. I'm leaving the wine in the garage until until February so it could get colder but we are likely near the seasonal low now. Most of the wineries in the area do the same.

So that's all the cold stabilization I'm going to get. I do not know what is best or perfect, but it's what I have. This year in particular, my idea is to leave it in the (unheated) garage until spring. It might get to upper 30s and that's fine. One of the local winemakers I really like, feels the seasonal temperature variations are important in the development of the wine. Not sure that's true, but I'm going with it. In an ideal world, I'd have a 57F basement, but not happening here.

And, the crystals once formed, do not redissolve. So if you manage to cold stabilize, rack at your convenience.

Best? Perfect? Good luck!

The way I look at it, there are two different reasons to conduct cold stabilization. The first is to adjust the acid in a wine that is tart. The second is purely cosmetic, getting rid of "wine diamonds."

If the acid levels are good, losing a bit of tartrate isn't going to affect the wine much. On the other hand, sometimes cold stabilization is an essential tool to use in reducing the acids to achieve more balance. In that case, the colder the better.

Most people keep their refrigerators set between 36° and 40°F. If your wine is stable to low to mid forties, sediment dropping out won't be much of an issue. Unless they leave a bottle of red in the cold for a couple of weeks. That might be enough for some tartrates to precipitate. If they do that, they kind of deserve what they get.

N.B. I am not a chemist. Nor am I a lawyer, a doctor, or an engineer. I simply read too much and spew back out what the collective someone else knows. While I may agree with their opinions, they're still just opinions.

 

[CDrew]

Best? Perfect? Good luck!

The way I look at it, there are two different reasons to conduct cold stabilization. The first is to adjust the acid in a wine that is tart. The second is purely cosmetic, getting rid of "wine diamonds."

If the acid levels are good, losing a bit of tartrate isn't going to affect the wine much. On the other hand, sometimes cold stabilization is an essential tool to use in reducing the acids to achieve more balance. In that case, the colder the better.

Most people keep their refrigerators set between 36° and 40°F. If your wine is stable to low to mid forties, sediment dropping out won't be much of an issue. Unless they leave a bottle of red in the cold for a couple of weeks. That might be enough for some tartrates to precipitate. If they do that, they kind of deserve what they get.

N.B. I am not a chemist. Nor am I a lawyer, a doctor, or an engineer. I simply read too much and spew back out what the collective someone else knows. While I may agree with their opinions, they're still just opinions.

It's funny, but after I posted last night we got all the way down to 32F! But the wine as measured by IR gun stayed at 46F, So it's going to take a lot more cold weather to change the temperature of the wine very much. I doubt we will get that. In my next life I'll have a big east coast style basement or a west coast style cave for aging!

This is a change for me as usually I do not cold stabilize at all (wine is aged in an unheated room inside and stays about 60F) but I did have some crystals form in last year's syrah and I'm hoping to get ahead of that this year. I'm not going to stress about it, but I will be interested in the result.

 

[winemaker81]

But the wine as measured by IR gun stayed at 46F, So it's going to take a lot more cold weather to change the temperature of the wine very much.

Although you get the largest acid reduction by chilling to 32 F / 0 C, getting the wine into the 40's may make a significant difference. It's still worth doing.

 

[BarrelMonkey]

I would love to know more about the kinetics of crystallization/crystal dissolution, but can't find any useful references. I will probably move my wines outside in a month or so (though they are getting pretty well chilled in my basement already - and the outside temps got down into the upper 20s last night). My still (white) wines could do with losing some acidity; the sparkling base wine needs to be as cold stable as possible, though I also plan to use some non-cold treatment (eg CMC) to inhibit crystal growth. I was thinking of getting some insulated reflective bubble wrap to put around (and on top of) my kegs each morning in an effort to slow down any daytime heating.