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What is the science behind wines "shutting down"?

Not something I’m particularly conscious of having experienced first hand, but I’ve noticed increasing mention, over the past few weeks on the community, of the possibility of wines “shutting down” or being in their “closed phase”, so curious to learn more objectively about this.

Many of us pay attention to drinking windows; some wines drink well young, and then quickly fade. Some don’t and need to slumber for years or sometimes decades…and then we hope they’re not past their best when we crack them open. It’s a bit of an article of faith.

And if they’re a bit “mweh”, we let them breathe for a bit and they come around. Or they don’t, and we put it down to experience; maybe our palate was having an off day; maybe it was never going to be an improvement on the barrel sample, but after thirty years “hey ho” it’s past its peak.

This peculiarity, however, seems to be more about wines that are fresh and vibrant in their infancy, before a period of “hibernation” during which time they are grumpy, unresponsive and monosyllabic. And no amount of persuasive aerobics will stir them from their torpor. Finally, though, they emerge from their silicate chrysalis fully developed, resplendent and basking in all their (potential) glory. Pure nectar!

Experiencing wine is such a subjective thing and creates such a wonderful wealth of anecdotes, but I’d be grateful if anyone can point at any empirical studies that have been undertaken to really explore the science behind this phenomenon - to help understand the why, the what, the how, and the when?

Or is there an MW out (t)here who can demystify this for me please?

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Hi @Cormski

Really interesting question, and actually one I was thinking about myself the other day following on from the Burgundy TWS taste event. So much discussion about wines going through a closed or dumb phase.

I’m certainly no MW, but I am a scientist (with a chemistry background) and I fully appreciate, and think it’s well documented, that the chemical profile in terms of aroma/taste/tannin molecules in a wine do evolve over time (emergence of tertiary flavours). However, my view would be that the biggest critical factor in terms of an average person judging a wine to be “closed” is the inherent variability in the person not the wine. Temperature, setting, mood, illness, glass, food, decanting and whether they’ve “invested” in the wine, etc all change a persons perception of a wine. In a controlled setting, with an individual who had a very refined tasting palate, then month by month changes might be perceived but I guess my scientific training makes me a bit of a skeptic!

In clinical trial parlance… There is no placebo arm in a wine tasting and rarely is the study blinded!

That should help get the debate going. Grabs coat and runs for the hills…

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Well, you’ve got to start somewhere!

I’m sure the inherent variability of the individual is an active factor to be considered. But I have been to wine dinners where - particularly in respect of red Burgundies - certain wines have been closed right down. You can calibrate it against other wines as well as other people’s palates under those circumstances, and there is no doubt the phenomenon exists. But Burgundy may be a bit of an outlier.

I think the most likely thing to happen is that certain characteristics fade and others emerge. Riesling is probably a good example of that. If there is a gap between those two stages, then there can be a time when the wine loses interest. It doesn’t close down though. White burgundies also do that at times - the initial characteristics owe quite a lot to the malolactic ferments, but they fade over a couple of years, and the extra bottle-aged characteristics don’t start to emerge until around five years old.

Maybe I am suggesting there are two phenomena (at least) we need to consider.

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@Alchemist @Ghost-of-Mr-Tallis - appreciate the thoughts. I’m not a practitioner, but I do have a biotechnology degree, so I reckon I have a basic grasp of the chemical processes involved overall. I suppose what interests me here, assuming (dangerous I know) fairly uniform conditions - is the non-uniform way in which these chemical processes purportedly transform or evolve the wine. I’d expect a steady, continuous process, rather than stop-start - or open-closed-open.

However, if the change curve does have multiple stages in it - there must be reasons for that, and presumably it should be possible to unpack the distinct chemical processes that are taking primacy in each stage, and map them out with some degree of predictability?

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Certainly no MW either, but I’d guess that the chemical processes that occur between “young and youthful” and “(potential) glory” are likely fairly complex.

It’s unlikely that molecule 1 (responsible for the flavour in youthful phase) directly converts to molecule 2 (responsible for glory phase). More likely a whole host of chemicals change (probably via intermediary reactions) to the set of ideal molecules responsible for aroma and flavour in the perfect phase.

Therefore, at any point, you risk opening the bottle with the “wrong” set of chemical compounds in (I.e. the wine is “closed”, because the molecules there don’t trigger a good response in our senses). If true that would theoretically mean that with control samples you could analyse the progress of these reactions and (in theory) pick out the “ideal” drinking phase. However, wine is a complex mix of chemicals and the analysis is likely so challenging to be uneconomical…

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@Tim1012 totally agree - I have no doubt it’s highly complex and challenging - exactly the sort of thing I’d expect there to be lots of academic literature on (I will confess that isn’t a rabbit-hole I’ve gone down yet).

If only I’d thought to interrogate ScienceDirect when I had easy access to it a couple of years ago… :confused:

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I’ll do that search for you when I get a spare half hour and post anything interesting I find.

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I’m sure that’s a factor. However, as one of the Burgundy tasting participants, I can say with some certainty that the wine I had that night had most definitely come out of a lengthy closed period. In its youth it had been a decent Pommard, but then became ‘nothing’. A brief tantalising PN bouquet for seconds, then gone. Nothing on the palate, nothing except some surly tannin. It most definitely ‘came out’. Had the same with claret and some Rhone too (Cote Rotie and Gigondas). What I do try to do is discount the occasional ‘off’ bottle, but these are usually quite easy to identify.

Therefore in my experience anyway, it’s much more about the wine itself.

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:+1: much obliged!

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I think this also highlights one of the other complexities - the almost infinite variability of wines, and the conditions from which they individually arise.

If there were enough data-points though, it might make a very interesting machine learning challenge and potentially throw up a bunch of patterns we might not be able to easily see within what appear to be binary states of open vs closed.

Apologies for digression - just noodling on how one might get to answers given the complexity of it all. I clearly have too much time on my hands to think about stuff I normally just take for granted… :crazy_face:

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Some of these things are known - the by-products of malolactic ferments such as diacetyl for example. Also, the origin of the precursors of the “petrol” flavour in mature riesling.
Tom Stevenson on petrol aromas

I’m not sure I’ve heard of anything on closed-down phenomena. In our discussion so far, we’ve really only considered those compounds that have positive organoleptic qualities. But there also exist compounds that have inhibitory or modifying characteristics. Most wine-lovers will know about trihaloanisoles and their role in suppressing tastes/flavours in corked wines. And not to forget that the presence of sulphur dioxide is intended to have an inhibitory effect on oxidative reactions, but at some point will run out.

If you go into the neighbouring areas of flavour and perfume chemistry there are more. Some things, for example indole, are powerful contributors to an overall scent impression of heavy white flowers (gardenia, jasmine etc.) but it just has a fairly faint aroma of mothballs on its own. And on it goes. I only really post this to give some idea of how complex an investigation may become, and should not restrict itself to just positive-contributing components.

Going back to an earlier point -

That would be fair enough if we restricted ourselves to kinetic first-order reactions. But not if other processes were at work, for example second-order reactions, or rate-limiting intermediate stages, or catalytic reactions.

Sorry, not a lot of structure to this answer, but just a few pointers.

Don’t we all?!

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Quite true and as you point out the sense of smell is so complex in terms of the interaction between various components that disentangling individual elements is nigh on impossible. I’m afraid I have come to the conclusion that though the phenomenon of ‘closing down’ is real - I’ve experienced too many examples to think it’s simply me not the wine - the scientific underpinnings are so complex as to make any real rationalisation impossible (I did quite a bit of background reading on this while studying for exams). I think reading Luca Turin’s book (sorry can’t recall the title, something like The secret of Scent?) on the science of smell is full of insights even if his central thesis is flawed.

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Interesting, @Oldandintheway. I have read a bit of Luca Turin and he is a lot of fun to read even when disagreeing with him at times. But I’m not sure what his central thesis you allude to is. Could you summarise?

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I have not comes across any scientific research on the subject of closed-periods in a wine’s development. And my feeling is that it would be expensive and difficult to do, and with no obvious source of funding. Complex and interesting subjects might be fun to speculate about, but they do not always lend themselves to experimentation.

My guess would be that shutting-down is a number of different types of phenomena. Ranging from excuses for a poor wine, through bottle variation and taster variation, to chemical changes in the wine. And my gut feeling is that the non-chemical-change explanations are likely to be the most common. And to the extent that chemical changes are responsible for shutting-down, there is no reason why the mechanism should be the same from wine to wine.

So even if experimentation, with careful and standardised tasting over many years, can demonstrate a plausible link with change in chemical composition, it might be of little value for wines not included in those particular experiments.

While spceptical, I wouldn’t rule out a chemical basis. I don’t see why a number of complex changes in one direction need result in tastes that move in a single direction - the relationship between chemistry and flavour is a complex one.

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His harmonic resonance idea seems to be fairly simplistic and there’s quite a lot of research showing it’s at least not the whole show, and probably only a small part of the overall explanation. I liked his book more for the descriptions of the complex nature of the aroma even of single compounds.

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Excuses for a poor wine is surely only valid if the wine doesn’t emerge from the ‘closed’ period? Bottle variation could be one, but I am very clear in my own mind about ‘corked’ wine, maybe wasn’t always when I was younger, but opening another non defective bottle soon demonstrates that…taster variation, perhaps, but if the same person tastes the same wine a few times over a few years it’s unlikely to be that I think. I would also exclude what I would call the natural evolution of a wine from primary to secondary then tertiary scents and flavours.

I have had wines which I just think are pretty indifferent, and haven’t changed over a long time period. Mas de Daumas 2006 is one that has never failed to disappoint for example, and some of the Jaboulet wines from a certain time period.

I agree that it would be both expensive and practicably challenging to try to research it, and I’m not even sure I see a lot of point, as it will probably vary a great deal anyway.

What would help is if experienced tasters flag when a wine is in their view in a closed period as suggested quite recently I think by @Taffy-on-Tour who I think did so with a Gigondas which I also hold and like a lot. I pay attention to that. I might still Coravin a glass to test the thesis, but I would hesitate once and maybe twice before opening a whole bottle!

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Well, yes. I have still heard it said at the time of tasting, when the wine has not lived up to expectations. The implication is that the speaker has a lot of experience of the wine.

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What you taste also depends on mood, health, what you have tasted immediately before you tried the wine. There are also a number of other factors like glassware, wine temperature, music, lighting. That is what I was thinking of.

There are a couple of wines I drink every week or two. Same vintage, same case, stored in the same place, and under screwcap. But sometimes the wine tastes so much better than others. Maybe I am just an terribly inconsistent taster, but I bet I am not the only one.

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great discussion, thanks @Ghost-of-Mr-Tallis @Oldandintheway @SteveSlatcher @MarkC all good points which helped me with my googling last night, and I’ve just emailed the authors of what looks like an interesting book chapter on “Ageing and flavour deterioration in wine” in Managing Wine Quality: Oenology and Wine Quality. Looks like it has some great primers for the science involved even if it doesn’t cover the age ingrat

It also contains a nice simplified illustration of the sort of change curves I was mentally picturing in an earlier comment - showing how the intensity of different sensory qualities wax and wane over time in a manner that visually describes what’s been said here – ie that there are likely multiple competing/overlapping phenomena.

A couple of comments on how uneconomical, complex and challenging it all might be to comprehensively investigate. What’s the point? If for no other reason than satisfying intellectual curiosity…?

I’m sure I’m not alone in: having squirrelled away a fair few bottles of wine over the years; having the regular dilemma of which one to open next; asking “are we there yet?”; and, sometimes thinking “gadzooks, that was a complete waste of my time and money!” So, anything that gets me closer to knowledge - rather than just guessing, however educated - is surely worth a punt?

And, just the collective wisdom (and cellars that must be represented) here on this community is reason enough; I love learning more from all the discussions that take place here! Thanks again.

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May I also add that hydration (or your lack of it) can contribute to how well, and what, your olfactory glands perceive in a wine.

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