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Heat damage experiment

I would like to have a go at an experiment looking at heat damage in wine.

The idea is to get a case of 12 and treat half of them badly and then see what difference it makes to taste over a period of time compared to the control samples.


  1. What wine to use? Ideally not something too expensive (it should be under £10/bottle) and with a closure that makes the test useful. Maybe DIAM. Red or white? Old or young?

  2. What is the “bad treatment” Maybe left in my car boot for 1-2 weeks in the summer (assuming summer returns) such that there will be ambient temps of up to 40C Or I could use our oven? Should it fluctuate?

  3. How long to run the taste tests for? Maybe test after 0, 2, 8, 20, 50 weeks?

  4. How to conduct the tests? A panel of 6 tasters, done blind? No conferring.

Anyone here tried such an experiment before? Anything you’d do differently second time around?


Great idea! I’d be very interested in your findings as I have less-than-perfect storage conditions at home for wine I intend to keep for up to a decade.

I haven’t tried anything like this deliberately but I did keep a bottle of Casillero del Diablo Cab Sauvignon (bought en route to a camping trip as emergency supplies but undrunk) in a car boot for at least 18 months. I opened it expecting it to be undrinkable but it seemed to have matured into something far more impressive than expected - so far from ruined, but probably accelerated maturation.

My only concern with the experiment is around the time you may need to see reliable changes - assuming you’re interested in storage conditions rather than shorter extreme changes in temperature (I may be wrong there!) If it is the former I’d suggest leaving it well over a year. I also think you’d need something which already has the potential to improve/mature. That doesn’t necessarily mean expensive stuff as I’m sure you know.


Interesting idea!

One thing which interests me - that’s repeated fluctuations in temperature - so not just too hot or too cold, but maybe warming up and cooling down multiple times.

Maybe leave a bottle in the garden for 6 months!


I think that boot of the car sounds like a good spot, because you will get the maximum temperature variations that you would find in any realistic storage situation.

I would be interested in seeing in the varietal made any difference. I’ve seen quite a few anecdotes on this forum of Cabernet Sauvignon being remarkably durable, so would be interested to see whether that extends to, say, Tempranillo.

For that one I think you definitely need cork rather than screw cap closures since, I believe, the problem with fluctuations is that they can draw air in due to expansion and contraction of the air already in the bottle. But I may be wrong! But I’m pretty sure it’s a different effect to cooking the wine.

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Of course the question then arises about what orientation the bottles should be kept in? If “breathing” then upright is probably best, but I guess it depends on whether you think breathing is more of a risk than a dried-out cork.

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Yes… I am hoping that by giving extreme treatment, I won’t have to go for so long a time. If (say) 4 weeks in a car boot oscillating between 15 and 40C doesn’t have much effect, then your regular domestic storage situation that might fluctuate between 15 and 25C is likely to be safe for a considerably longer period.
One does also want a reasonably fast answer for it to be able to inform ones cellaring strategy!


Careful, now, or you could find yourself drifting into peer review territory! :rofl: Got to be done right!


One complicating factor is that heat damage may impair the ability of wine to age. So that a wine that has been exposed to high temperatures may taste ok immediately afterwards, but start to deteriorate a year later. I have seen this suggested by Jamie Goode, but I am not sure what the evidence for it is.

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OK… My schedule did go up to 50 weeks, but there’s room for another at 100 weeks! There’s not going to be a perfect answer to the vague question that is essentially being posed here.

Interesting. I suppose the experiment has to be designed to reflect what you’re trying to find out. I would think in hot summer weather wine could cook quite quickly in a car boot, but would confirmation be of much use? A car boot is not a place many people would deliberately store wine.

Perhaps a more useful experiment might be to compare wine kept in ideal conditions with wine kept in a kitchen cupboard, or under a bed, or in the attic, and over quite a long period. This might give more helpful information on the sort of choices that many people have to make. Certainly what I would find very helpful would be some insight into how wine stored in everyday household conditions performs compared with perfectly stored wine. Without any substantial proof I’m already convinced that wine left in a car at 40 degrees will not do very well for very long.

Any suggestions for wines that might fit the bill? Obviously these will be drunk and enjoyed (hopefully!) so it’s not as though money spent will be wasted.
Perhaps something like a Rioja is a good option, but I think one should be looking for a wine style where “freshness” and fruit purity is a significant part of its appeal. So maybe Rioja isn’t so good (because mature Rioja is still quite nice).
Maybe a Pinot Noir or a Cru Beaujolais or something?

Phrasing the question is very important. Otherwise I might just get the answer 42…


Ah, do you intend to “cook” some of them in a car boot for a few weeks then store all the bottles together afterwards before a later comparison? I hadn’t understood that.

The answer may well be 42!

Yes, that was the plan. Although, I suppose I could continue cooking.

Talking of “cooking” reminds me of some of the bottles of wines I collected from my late father’s flat after he died. They were part of a few cases of white Burgundy bought EP from TWS but they had been stored in his small kitchen.
Sadly, obviously madeirised but drinkable. The cases that I withdrew from reserves later on were far better.


As you want a fairly quick result I would think you’d want a shorter lived wine or quicker maturing (is that the same thing?). Maybe a mid priced Bordeaux? For example a Chateau Pitray, Cotes de Bourg that I have: vintage 2015 (so a good year) drinking from '18 to '24 so three years to its window and then six in it (allowing for TWS conservative window!). A newer vintage of something like would seem about right?

Thinking more about the question for my own uses… Part of my wine storage area is in a garage that can get hot in the early evenings during a heatwave. I want to know if I can store my lessers wines there without too much degradation. One side of the garage is worse than the other, and the poshest stuff goes into a wine fridge.

Given that heatwaves in this country rarely last more than 2-3 weeks, if I simulate the mother of all heat-waves in my car boot (it does get hot in there) and leave the wine in for 2-3 weeks before removing it to give it a chance to recover, then if those bottles aren’t too bad, then I have a positive answer.

So I think take them off the heat at the same time.

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Apologies for not reading your original post carefully enough. Just thinking now it might make economic sense to try 1 bottle in the hot car first. If it’s already ruined after a few weeks then there’s not much point trying with several more.

Of course that would need at least a couple of hot periods to do. But it’s still June; hopefully we still have a few hot periods to come!

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That’s a good idea.