When Wine Freezes

Hey Everyone,

Longtime lurker, relatively new poster. I had an interesting experience yesterday, and wanted people’s thoughts. My girlfriend left a bottle of '98 Von Kesselstatt Kabinett (can’t recall the vineyard) in the bottom of her small fridge. Apparently the fridge became too cold, and the wine completely froze. When we discovered it last night, the wine had obviously expanded while frozen, and the cork had broken through the capsule and emerged about 2/3 of the way. So of course the only thing to do was to pull the cork, and let it de-frost (we have other bottles, so no harm done). Interestingly, when it was 80% unfrozen I sampled it, and it had a terribly weak nose (even when warmed in the glass), and was completely watery and almost tasteless. But when it was 100% unfrozen the palate came back together, the classic nose returned, and all seemed more or less in order (if not 100%). The other glass, even when completely warmed, lacked sugar, intensity of flavor, and a aromatic nose. Which leads me to conclude that a fair amount of the sugar was the last thing to melt. Could that actually be the case? Is wine altered structurally or harmed when frozen? Or is the harm simply from the cork alteration (whether it pops out of not, I assume the heat fluctuation will leave the cork completely vulnerable to oxidation). Is red wine affected differently by being frozen than white wine?

I can’t address the science, but many times I have thrown an open bottle of wine in the freezer when we are going on vacation, and thawed it out when we came home. Other than sometimes some precipitation of tartrates(?) in white wines, I find that freezing is an excellent preservative, as one would intuitively expect. We do indeed consume the wine very soon after thawing, and it is just fine.

1st: if you would like to keep a frozen bottle, do NOT pull the cork!.
Leave it standing at room temperature and wait until all ice has melted. THEN push the cork back into the bottle.

(sure, if you wanna taste/drink it it doesn´t matter, but when 20% are still frozen part of the extract are also still frozen, so no surprise that it tasted no good.)

I cannot guarantee that the wine afterwards will be exactly the same as before, but at least it will be well drinkable.

With red wine when stored too cold or even freezing it can happen that colour pigments will fall out and sink down to the bottom. So the wine will lose colour.
I have two or three bottles like this in the cellar (auction purchases) of an orange colour.

Also once I received a Grand Cru Burgundy (Bonnes Mares Vogüe) 1957 as a present … almost de-coloured, but cloudy. When I left it standing upright for weeks it was completely a white wine with heavy red sediment 1 cm thick.

A year later I served it to friends including the donator. The discussion went into the direction if it was a Chevalier-Montrachet or even a Montrachet …
It was a great white wine, but nothing reminded us of a Bonnes-Mares.

Benjamin, Welcome to the board. I’m a chemist, so you’d think I should know what’s going on, but wine is a complex beast. The cork pushing out is completely normal - when water freezes, it expands by almost 10%. Adding any kind of “impurity” to water will reduce the freezing temperature (called “freezing point depression”). That’s true when you add a liquid (how antifreeze works), as well as a soluble solid (which is why they salt the roads in cold climates). So, both ethanol and sugar act to drop the freezing point of a bottle of wine, relative to pure water. A 14% abv wine will freeze at roughly -6 degrees C (about 21 degrees F). In the case of your Kabinett, the alcohol is probably a little less, but let’s say the additional sugar probably makes up for that, so I would think the freezing temp would be about the same, maybe a little higher.

Now to your observation of the change in taste. I would have predicted that as the wine thawed, the first parts to thaw would contain more water than alcohol (which seems backwards, but is how fractional freezing of a water/ethanol solution works). That might explain your observation, since you had a much more watery mixture early on. Similarly, I think it can be said that the sugars and other flavor compounds are selectively retained in the frozen component, though I’m not as certain about this. Once the entire bottle thawed, you got the “normal” wine back.

What you described is related to how ice wine is made, where grapes are allowed to freeze on the vine. Inside the grape, water tends to freeze in a more pure form, leaving behind the sugars and flavors in a more concentrated liquid, which can then be pressed from the grapes while the more pure water is still frozen.

Anyway, it was a good experiment, and demonstrates that freezing a bottle of wine isn’t necessarily a death blow, as long as the cork remains partially intact.

Part of the lack of aromas would be explained by the temperature, I think. The volatile elements that give the wine its aroma won’t evaporate when the wine is still close to freezing temperature.

Good point, John.

John, that was my original thought, but like I said, I let it warm up to look temperate alongside a glass from the completely unfrozen bottle, and the two bouquets still seemed to be different.

Thanks for the great thoughts Alan. Ice Wine was actually my first thought when we discovered the bottle, so I figured it would be fine if let it defrost. It made me wonder about red wine though, and whether, as Gerhard alludes to above, it might have some affect on the tannins or color pigments. I thought perhaps that the process of freezing a wine might scramble the structure of the red wine (color pigments, tannins, etc) in a way that wouldn’t re-figure itself upon thawing. But chemistry was some time ago, so those thoughts were merely the speculation of a non-scientist!

Another question which came to mind, with perhaps no good answer, is whether a wine would be harmed by long-term freezing? And if not, would that process cause the evolution of the wine to cease while it remained frozen?

Well, “scrambled” is indeed the scientific term we normally use I don’t really have an answer, except that A) you wouldn’t expect any real chemistry in the wine to change - reactions only slow down at lower temperature; and B) the only thing that might happen is some compounds could precipitate out as they get less soluble at lower temperature. This can definitely happen to tartaric acid. You can sometimes find tartaric crystals collected either on the cork, in either white or red wines, or at the bottom or sides of the bottle. This would probably be an indicator that the wine was at relatively cool/cold temperature for a long, stable period of time. The other indicator I’ve seen (in particular) is in Sauternes, where you might notice light “flakes” floating in the bottle, a little like a snow globe. I believe these are also tartaric crystals that have precipitated out. To form light, fluffy flakes like that generally requires a rapid cooling, so that the crystals don’t have time to form slowly into more recognizable crystal forms, and come out of solution in a hurry as smaller, lighter precipitate. I’m not aware of anything else unique to red wine that precipitates out at cold temperatures, but you would notice this on the side of the bottle if it did happen. You might not be able to tell the difference between more normal tannins settling out.

Another question which came to mind, with perhaps no good answer, is whether a wine would be harmed by long-term freezing? And if not, would that process cause the evolution of the wine to cease while it remained frozen?

Well, freezing does two things: it obviously drops the temperature, which will slow down any reactions. And, perhaps even more importantly, it stops motion of the molecules, so they can’t bounce around and run into other reactive molecules. So any development or degradation of the wine while frozen should be much, much slower than in the liquid state at higher temperature. It’s not perfect, things can still slowly diffuse, particularly gases like Oxygen, and react, just a lot more slowly. There have been discussions in the past about freezing wine to preserve bottles after being opened (see a post above). I’ve done this successfully a number of times, and even left the bottle frozen for months before thawing and drinking. I’d say the longer you leave it frozen, the more likely it is to deteriorate, just like leaving a bottle at liquid temp in the fridge. So, maybe a bottle in the fridge will last a day or two, sometimes more for certain wines, and a bottle in the fridge will easily last a week or two, maybe even a month or two, or more.

Alan would know the chemistry/physics better, but I wonder if the process of warming up gives off volatiles that wouldn’t be released from a wine at a stable temperature.

I purchased a case of 99 Dugat-Py Charmes-Chambertin along with some 99 Groffier Bonnes Mares and Beze on pre-arrival in the early 00’s. The wine froze on its journey to Australia and I was offered a large discount to keep the order. Every bottle has been sublime.

Nope. Not if you just let it warm up naturally at cellar or even room temperature. If you put it in the oven or microwave to speed it up, then maybe the outer edges will heat up more, but I assume that’s not what you meant

I had two bottles of Trapet Chambertin freeze during delivery and push the corks a few years ago. (Not a $30 Oregon wine, of course - that would take all the fun out of it.) We drank one immediately (after it thawed) and it was fine; I took a rubber mallet to the other and drank it many months later. It didn’t seem any the worse for wear. Hardly a controlled experiment and I wouldn’t do it on purpose, but it was interesting.

My silly thought was that freezing would be a cleaver way of preserving wines at their developmental peak (or at whatever point you wanted to drink them). So one could, say, sit on a case of Batard-Montrachet until it began to open and unwind, but then freeze the remaining bottles before they became developed to the point where premox becomes more likely. Or choose another wine development scenario that is less controversial – perhaps that moment when a wine seems to balance between fruit and secondary flavors, which some people seem to shoot for. Basically it would be a way to drink a wine at a point you like without having to drink it all at once.

Now obviously there are plenty of problems with this, not least of which is bottle variation. But it was a fun thought!

My experience goes against the grain compared to most others in this thread. Based only on a small handful of occasions when whites have been accidentally left in the freezer too long, I have in most instances found the wines disheveled and severely altered. Wines that have remained frozen for a few hours up to a few days and then thawed in room temperature and opened have had acid/sugar balance altered and seemed slightly disintegrated, almost undrinkable compared to their normal state. I can’t explain why, but kind of strange to see many others with almost opposite stories.

I have never tried to thaw a wine and keep it for further ageing.