Temperature Fluctuations In Passive Cellars

When it comes to wine storage I’ve always heard: Constancy good, change (fluctuation) bad. So, say you have temperature swings of 20 degrees annually in a passive cellar: 45-65 degrees. Does it affect the maturation of the wine?

i think the concern with fluctuations comes from sudden fluctuations such that the expansion/contraction of headspace can pop a cork, force fluid from the bottle, etc. the subtle seasonal changes, while drastic, are less likely to cause a shock to the systems and cause a breach.

I would think the ranges would speed up the process of aging, but otherwise the wine ought to be fine. I experience a range from the mid-50’s to 68/9 with a few short spikes up to 72 if the temperature sits at 90+F during the day for several days and the nights are in the 70’s and I don’t see too much advanced degradation.

Michael - your cellar temp seasonal swing is fine. Relax and enjoy your wine.

I appreciate your concern and reassurance, but the question is for educational purposes only. In the south, high temperatures and water tables do not allow for passive cellars.

Here’s something I have posted before (maybe back in the ebob days):

I believe far too much importance is given to stability of temperature, or at least preventing “rapid” variations. Some quick calculations yielded the following results for the change in volume as a function of temperature (assuming pure water, results would not be much different for a water/alcohol mixture of real wine):

Temp(F/C) density     volume     %change     ml/750
50/10.00    0.999728    999.705    -0.02951 -0.22
55/12.78    0.999433    1000 0 0
60/15.56    0.999043    1000.390    0.039037 0.29
65/18.33    0.998563    1000.871    0.087125 0.65
70/21.11    0.997998    1001.438    0.143788 1.08
75/23.89    0.997354    1002.085    0.208452 1.56
80/26.67    0.996634    1002.808    0.280845 2.11
85/29.44    0.995846    1003.602    0.360196 2.70
90/32.22    0.994987    1004.468    0.446844 3.35
95/35.00    0.994063    1005.402    0.540207 4.05
100/37.78    0.993078    1006.399    0.63993 4.80

Looking at the change in volume around 55 deg F, you can see that we expect a variation of about +/- 1/4 ml in moving down in temp to 50, or up to 60. That’s 0.5 ml total variation in liquid volume between 50 and 60 degrees. This variation will change the internal pressure, as the remaining air in the bottle expands or compresses. Assuming internal pressure is 1 atmosphere, and an ullage of about 1.5 cm (giving about 3 cc air volume), we get a change in internal pressure ranging from +20% to -15%. For the typical cork (surface are ~0.44 sq in), that is the equivalent of roughly 1.3 lbs of force exerted on the cork from increased pressure inside the bottle.

I’m not entirely sure what conclusions to draw from this, except that I don’t think I’m going to worry about that 1lb of force exerted on the cork

An anecdote I often relate: I have a bottle of plonk white wine that was given away as a promotion, probably around 1988 or so. I’ve kept this bottle, upright in my house, through all those summers, and temps ranging from the 50s into the 90s, for nearly 20 years now. The ullage on that bottle is perhaps 3cm, and probably started out at 1 or 2. Not that I recommend that type of storage but a good cork makes a good seal - and a bad cork conversely makes a bad seal, probably regardless of storage conditions.

I don’t think anyone knows.

The “Shadow” knows neener

Can you insulate against winter cold dips? I don’t see issue, but 20 degrees is 20 degrees. Would rather see you cut that in half. For the most part as long as they are gradual, you should be fine.

I think 45-65 is fine. I also look at this when shipping wine, daytime high and nighttime low. If your cellar air temperature is going from 45- 65 your wine is never with of those. A wine cellar full of bottles of wine has a huge thermal mass and the liquid will be near the average for the majority of its life. If you really want to know the temperature of your wine get one of those in bottle thermometers. I got one that controlled an a/c unit as a gift and quickly realized it was way to slow to react as it was based on wine temperature. I have used it to see the fluctuation in temperature of the actual wine in the bottle and its 1-2* a day. I have tried thermometers thru the cork as well to see temp of actual wine and its nowhere near as high or low as you air temps.

The bigger concern is humidity. Especially in winter. Use a portable humidifier if necessary.

My passive cellar, sitting just below me, ranges from 45 to 64 … and has for 20+years. My wines are great. If anything, it swings to the low side for 6-7 months. I think my wines age more slowly than those I keep in my Vinoteque. Right now it is 58.3.

I wrote a post some days ago about finding similar swings in temperature all over Europe in passive cellars of well known domaines. Makes no difference. It’s the sudden spikes that are dangerous.

That was just about exactly the range I had in my basement in San Francisco for 10 years, and I’ve never had any spoiled or unusually advanced bottles of from that time, even 20 years later. I had 30-40 cases, so it was a reasonably large sample size.

This is the conventional wisdom, but I’ve always wondered where it cam from, and why people just accept it as fact? If by “spikes” you mean that the upper temp remains relatively modest (say, below 70), I find it hard to think of a mechanism by which the wine could suffer in any way.

Mine ranges from 55 to 65. I’ve pulled some very good bottles out from it that have seemed less developed than what I see described in Cellartracker from other tasters.
Fwiw I like to think that my cellar conditions play a role in the wines I drink just like vintage, producer and variety influence the final product

A few years ago in St Maartin, I bought a couple bottles of wine on the way back to the villa. Left them in the car while we stopped for a quick libation. Well, quick turned out to be two hours with the wine in the back window (not smart). Corks were half out and the wine was “hot” and tasted awful.

That’s a spike.

Jim, likewise. I feel that my storage prolongs the life of my wines or, in other words, my wines develop more slowly than other CT tasters.

Can’t tell you the times I’ve read that a wine is past the prime and mine are youthful and vibrant.

I cycle my unit on and off every 12 hours to save energy (and because the fan on my Kenmore unit starts to run nonstop if I leave it on too long), and it causes my cellar to go from 57 to 59/60F over a 24 hour period.

I have never been concerned about this as a “spike”, as I assume the wine temp remains around 58 the whole time.

Thoughts?

Of course, no one would disagree. But what about a “spike” from 55 to 65 in a few hours? I assumed that was what you were warning about above.

As you can see, lots of opinions.

Here are some more. For some reason people seem to think that the speed of the fluctuation matters. There is no evidence that I know of to support that. It’s the fluctuation, whether over a few days or months that matters.

Then there are other people who think that the seasonal shifts are somehow more “natural” and are the way you’re supposed to age wine. I’m not aware of any science supporting that either.

There’s an acceleration of reactions that you might not want. There are many many reactions taking place in the bottle at any given time, but as you raise the temps, the growth of Brett and bacteria accelerate and those are things you don’t want. So each time you spike the temps, you make sure to add a little more negative reactions to your wine.

Finally, not all passive cellars have fluctuating temps. In some parts of Europe they dig caves into the mountains. Those cellars are cold as hell winter and summer, with little fluctuation. You take the wine out for a day or so and simply as a result of the temp change it starts refermenting and blows out the cork or blows up the bottle. If you’re dug into stone, you don’t have a lot of temp fluctuation.

So all in all, if I were to have fluctuations in temps, I’d have a back-up cooling system. And it’s a timely question since I’m moving this weekend and I have a few cases to move. Some are from the 1980s and I’d just as soon not have them go thru any temp shifts.