Effect of wine storage at 45 degrees?

[DougS]

I have 2 cellars set at 47°F

How long have you been doing that? Have you ever compared the same wine from your 47 degree cellars and a 55 degree cellar, after some period of aging?

[Jayson_Cohen]

There are a number of temp controllers used for home brewing. I used to use one on a chest freezer for controlled fermentation temps for lager beer. Since they can fail, I would probably not trust one on a freezer with thousands of dollars of wine in it, but it could be used on a spare refrigerator to maintain 55 degrees. I expect that the freezer would no longer be freezing, but the if that’s not important to you, this might be a solution. I’m planning to try it out on my spare refrigerator once the freezer is empty.

I used a temperature controller set to 52 deg F on a full size upright freezer in my parents’ basement to store wine when I first started collecting. I filled it up, about 70 bottles, and it worked well for about 17 years without a problem or failure. Most of the wine was there for the full period. Because of the large thermal mass, the refrigerating unit barely cycled. Although I have since moved the wines and don’t use it anymore, the wines aged perfectly, and I’m still drinking some of them.

[GregT]

What I am pretty sure about is that you won’t have a lot of precipitation at 45°F. In Tokaj, the temperatures at Oremus and Royal Tokaj and most of the others is a constant 10°C, or 50 °F. They have wines in there going back decades and the temps don’t really change at all, winter or summer.

Same in Eger, where some of the cellars at least feel even colder. In both places, they’re dug into the mountainsides and are surrounded by hundreds of feet of rock.

The interior air temperature is conditioned by the temperature of the ground at the average depth of the wine cellar, and to some extent also the insulating value of the material protecting it from outside air. But if you have massive amounts of rock, like a mountain, the R value of the rock doesn’t matter so much.

The generally “accepted” temperature range is 7–18 °C (45–64 °F) mostly because the cellars in Europe are found in that range. The French didn’t dig caves into the mountains so much as build chateaux with stone walls, as did the English, and before refrigeration, those served for cold storage, but because they were not necessarily deep in the ground, they generally hit 55 °F, some higher.

In Germany, the cellars I’ve asked say that their temps are 10°C, or 50 °F.

[Alan_Rath]

Ben,

Curious - how do you know that both tartrates and tannins were precipitated? Did you do a tannin analysis? Just really curious . . .

I can say that when I was at UC Davis, part of my master’s thesis was looking at tannin development in the same wines at different temperatures. Granted, these were freshly pressed wines but I had them stored at 41, 50, 68 and 86 degrees an a temperature controlled lab. I took samples from each sample bottle over an 8 month or so period to note changes in color intensity, anthocyanin presence, tannin development, etc (this was NOT meant to be used for taste or olfactory analysis).

The data showed what one might expect - the development of polymeric pigments (tannin-anthocyanin complexes that are color and SO2 stable) increased with increased temperature, with the type of polymeric pigment created (short or long chain) depending upon ‘starting materials’. But there was no decrease in total tannins whatsoever, regardless of the temperature.

Just another data point to consider.

Cheers.

Exactly. It’s a misunderstanding that tannins “precipitate out”. They do not. They polymerize (that’s my understanding), which is a chemical reaction that benefits from higher temperature (as Larry said), and also takes significant time under normal bottle conditions. Precipitation is essentially a solid salt being formed because the solution reaches its saturation point at lower temperature.

I’m not the world’s expert on this topic, and I know that much of the following will be familiar to yourself and other people on here - I’m just including it all so anyone reading can (hopefully, if I’m doing it right) follow along.

All dissolved solids in wine have solubility limits and will precipitate out of an ethanol-water solution if (a) those limits are exceeded and (b) the kinetics of the precipitation reaction are sufficiently rapid to allow it to happen on the timescale of interest. I explain this to tasters by observing what happens to the last drops of wine left behind in a finished glass. As it dries out, it leaves behind a solid residue, but that solid residue starts to form before the liquid has totally vanished, because the evaporation of the liquid is concentrating these dissolved solid compounds in the residue until their concentration exceeds their saturation point. Because the solubility of solids in liquids is, as a general rule, higher a higher temperature, you can also sometimes achieve this saturation by lowering the temperature. Compounds that are near their saturation point at 55 F may precipitate at lower temperatures. Of course, at lower temperatures, the kinetics are slower, so it can take a longer time for this precipitation to happen. This principle is indeed used for the cold stabilization of white wines by precipitating out tartrates at ~0 C prior to bottling, but the same principle can also apply to other dissolved solids.

Some dissolved solids are present in wines at concentrations far below their solubility limits and so never precipitate out of most wines under reasonable conditions. These include things like sugars, most acids (except tartaric), and most salts (chlorides, sulfates, phosphates, etc). However, tannins are present in many red wines at concentrations quite close to their saturation point. In fact, during extended maceration it is not uncommon for tannins to start precipitating out of the wine, even as they continue to be extracted into the wine from the skins. The controls on tannin extraction and solubility in wine are still not very well understood.

The reason tannins precipitate out of wine when they polymerize is that highly polymerized tannins are less soluble in water than less polymerized tannins. Their large size increases their hydrophobic character and makes them more likely to clump together than to remain complexed by water molecules. The resulting solid is not a nicely ordered ionic salt like potassium hydrogen tartrate but is a pretty unstructured glob of tannins and other tannin-bound molecules that help to link tannins together. This mushy, unappetizing structure is common in organic precipitates, and is also observed in other phenolic precipitates such as the slimy green quercetin precipitates that can occur in Sangiovese. The disordered structure of these precipitates is reflected in their macroscopic properties: organic precipitates don’t usually form nice crystals.

One of the fun details of this topic is that most high-tannin wines actually already contain tannin precipitates suspended in the wine. They are prevented from settling out by gravity by being very small - and so having a very very slow settling velocity in a fairly viscous wine - and by being juuust loosely held in solution, probably by some kind of colloidal structure. If you stick them in a centrifuge you can agitate them out of suspension. I have not explored the sensory effects of this but it would be fun to do one day.

Ben,
Sure, the very definition of precipitation is when a substance reaches its solubility threshold. I can’t comment through experience on what happens during fermentation; but in most cases, just cooling down a stable bottled wine should not result in any significant settling out of tannins. I refrigerate opened bottles all the time, and can’t say I’ve ever seen that.

[J.Vizuete]

With shipping season upon us and the common experience of “too much wine, not enough storage” I find myself overflowing from a couple wine fridges and an offsite (with many cases to come!)

So I have some cabinets in my air conditioned home where I’m putting bottles (typically lower price point), and many of them will sit there a long time until I have space in the fridge to move them to. The temperature is 65-75 seasonally, and might get as high as 80 when we leave town.

My questions are: How long would you feel comfortable with that type of storage? and
Would you rather store your wines in a regular refrigerator at ~40-45*F ?

[Marcu_Stanley]

isnt it true that different chemical reactions are happening, some which are more or less effected than others by temperature? Like the tannic structure will last much longer with the cold, but the rate of change with sugars wont be impacted as much? Essentially changing not just when the peak is, but what the peak is?

I believe this must be true. Over the years I’ve had many opportunities to drink the same wine / same vintage from different sources/storage conditions. After a couple of decades the wines don’t just taste more or less advanced, they taste different — different structures, balance, even subtly different flavors

[GregT]

With shipping season upon us and the common experience of “too much wine, not enough storage” I find myself overflowing from a couple wine fridges and an offsite (with many cases to come!)

So I have some cabinets in my air conditioned home where I’m putting bottles (typically lower price point), and many of them will sit there a long time until I have space in the fridge to move them to. The temperature is 65-75 seasonally, and might get as high as 80 when we leave town.

My questions are: How long would you feel comfortable with that type of storage? and
Would you rather store your wines in a regular refrigerator at ~40-45*F ?

I can tell you that I’ve stored wine in the regular fridge for years with no ill effects. I’ve also stored wine accidentally at 75+ for a few years, which wasn’t a good plan. A couple wines were OK, most weren’t and in fact, they turned kind of brown.

While I wouldn’t pick 70+ for long term storage, if you figure that most retail shops are around 68-75 most of the time and if they don’t leave heat or AC on at night, the wines go through some temperature shifts. If you’re comfortable buying wine from a retail shop knowing that the wine may have been on the shelf for a year or two, then you’re going to be comfortable drinking your wine stored at those temps. Most wine is hardier than we think. OTOH, I have noticed shifts in wine stored at room temp for a year or so and those shifts weren’t nearly as pronounce in wine stored in my cellar. A few Zins for example, seem to have lost the bright fruit faster than those stored cooler, and a few bottles of Syrah seem to have lost a bit of spice. But in other cases, there’s little difference.

My conclusions are that 1)it really depends on the wine and 2)the actual temps and their duration and 3)your palate.

[Victor_Hong]

With shipping season upon us and the common experience of “too much wine, not enough storage” I find myself overflowing from a couple wine fridges and an offsite (with many cases to come!)

So I have some cabinets in my air conditioned home where I’m putting bottles (typically lower price point), and many of them will sit there a long time until I have space in the fridge to move them to. The temperature is 65-75 seasonally, and might get as high as 80 when we leave town.

My questions are: How long would you feel comfortable with that type of storage? and
Would you rather store your wines in a regular refrigerator at ~40-45*F ?

I can tell you that I’ve stored wine in the regular fridge for years with no ill effects. I’ve also stored wine accidentally at 75+ for a few years, which wasn’t a good plan. A couple wines were OK, most weren’t and in fact, they turned kind of brown.

While I wouldn’t pick 70+ for long term storage, if you figure that most retail shops are around 68-75 most of the time and if they don’t leave heat or AC on at night, the wines go through some temperature shifts. If you’re comfortable buying wine from a retail shop knowing that the wine may have been on the shelf for a year or two, then you’re going to be comfortable drinking your wine stored at those temps. Most wine is hardier than we think. OTOH, I have noticed shifts in wine stored at room temp for a year or so and those shifts weren’t nearly as pronounce in wine stored in my cellar. A few Zins for example, seem to have lost the bright fruit faster than those stored cooler, and a few bottles of Syrah seem to have lost a bit of spice. But in other cases, there’s little difference.

My conclusions are that 1)it really depends on the wine and 2)the actual temps and their duration and 3)your palate.

Yeah, for many years, my refrigerator has been chilling LLC 1990, Montrose 1982, LLC 1994, Leoville Poyferre 1982, Pichon Baron 2003, La Jota 1994, Laurel Glen 1994, LMHB 1990, etc.
I am not worried, and have found no problems.