Does Tartness Fade With Air?

My wife and I visited a nice little BYOB restaurant in Brooklyn last night and brought along a 1991 Campo Viejo Reserva from Rioja.

As happened with this same wine last time we had it, when the bottle was first opened the wine tasted too tart, but after 15 or 20 minutes it seemed to mellow out and was a very enjoyable mature old style Rioja. Has anyone else experienced this? Just wondering if it's the food, or if tartness does soften with airing. Tom V

just a guess; but i'll go for a small bit of malactic fermentation having started in the bottle and the very slight bit of spritz wasn't obvious as such and seemed alike acid. it would after all have been carbonic acid or some similar thing. normally acid wouldn't change like that as far as i know.

I agree with David's comment. However, could it be that tasting it initially was before the food arrived while afterwards it was with the food? The presence of food can alter perceptions.

Tom,

I've experienced this many times with European wines. Less so with New World wines except my own! European wines often go into the bottle with higher free SO2 than many domestic wines. They also generally have a lower pH, which makes the SO2 more effective at numbing the midpalate. What you are experiencing is the oxygen combining with the free sulfer dioxide (SO2) in the glass over time. The acidity doesn't change chemically, but our perception changes as the sulfer blows off and the midpalate fleshes out, absorbing the sharp edge of the tartaric acid. The result is more flesh and fruit in the middle, which lessens the PERCEPTION of acidity.

Jim Lester

Tom,

I've experienced this many times with European wines. Less so with New World wines except my own! European wines often go into the bottle with higher free SO2 than many domestic wines. They also generally have a lower pH, which makes the SO2 more effective at numbing the midpalate. What you are experiencing is the oxygen combining with the free sulfer dioxide (SO2) in the glass over time. The acidity doesn't change chemically, but our perception changes as the sulfer blows off and the midpalate fleshes out, absorbing the sharp edge of the tartaric acid. The result is more flesh and fruit in the middle, which lessens the PERCEPTION of acidity.

Jim Lester

That's very interesting Jim. I know food changes our perception of wine and while I felt that might be part of the explanation, the change just seemed to pronounced for that to be the case. The SO2 effect seems to me to accurately describe what we experienced with this wine. Next time I pop a bottle I think I'll decant it 10 minutes before drinking it. Thanks for the insight. Tom V

I go with three potential factors: the influence of food, oxygen, and time, as in acclimation to acidity over time, not to mention the possibility that low pH stimulating saliva lessening the impact of acidity.

There would have to be an awfully high dose of SO2 in a wine vintaged 1991 to make such an impression, so high you wouldn't get past the nose. I don't buy that explanation at all.

Thomas,

You are quite correct. I didn't notice the vintage date listed before I made my comments on free SO2. The free SO2 would all be combined into the wine at that age.

However, I stand by my comment that there is a numbing effect from bottling SO2 levels that persists many years after bottling. This is readily apparant to anyone who drinks old Bordeaux or old white Burgundy. I have had many old bottles of both ( and other wines from Europe) that exhibited a burnt match stick aroma (sulfer) when opened into a decanter, but after an hour of airing this stink dissipated. As soon as the smell is gone, one can better perceive the fruit and body of the wine. I am a lowly grapegrower/winemaker, and not a PhD chemist, but I still think we are dealing with the after effects of SO2 or residual compounds. I do know from my own lab experiments with total acidity that acid levels in properly cold-stabilized wines remains pretty constant throughout the life of a wine.

And of course I could be mistaken!

Jim Lester

Thomas,

You are quite correct. I didn't notice the vintage date listed before I made my comments on free SO2. The free SO2 would all be combined into the wine at that age.

However, I stand by my comment that there is a numbing effect from bottling SO2 levels that persists many years after bottling. This is readily apparant to anyone who drinks old Bordeaux or old white Burgundy. I have had many old bottles of both ( and other wines from Europe) that exhibited a burnt match stick aroma (sulfer) when opened into a decanter, but after an hour of airing this stink dissipated. As soon as the smell is gone, one can better perceive the fruit and body of the wine. I am a lowly grapegrower/winemaker, and not a PhD chemist, but I still think we are dealing with the after effects of SO2 or residual compounds. I do know from my own lab experiments with total acidity that acid levels in properly cold-stabilized wines remains pretty constant throughout the life of a wine.

And of course I could be mistaken!

Jim Lester

Jim,

No doubt that high SO2 affects the palate as well, but I don't see it as a problem in this particular situation. High SO2 strips wine.

Of course, having not tasted the wine ourselves, we are all speculating. My speculation is that it is more perception on the taster's part than it is the wine itself, except for maybe a wine so unstable that it falls apart after 15 minutes exposure to oxygen, which is a possibility and which would tell me to buy a different wine...

Tom,

I've experienced this many times with European wines. Less so with New World wines except my own! European wines often go into the bottle with higher free SO2 than many domestic wines. They also generally have a lower pH, which makes the SO2 more effective at numbing the midpalate. What you are experiencing is the oxygen combining with the free sulfer dioxide (SO2) in the glass over time. The acidity doesn't change chemically, but our perception changes as the sulfer blows off and the midpalate fleshes out, absorbing the sharp edge of the tartaric acid. The result is more flesh and fruit in the middle, which lessens the PERCEPTION of acidity.

Jim Lester

I am not sure about this. Why would such a deadening affect the perception of acidity disproportionately?

Another explanation would be that the perception of the components of wine is affected by their balance, for example if the fruit of a wine becomes more evident the acidity becomes less evident, as happens for example when wine recover from shipping or bottling.

Oliver McCrum wrote:

Another explanation would be that the perception of the components of wine is affected by their balance, for example if the fruit of a wine becomes more evident the acidity becomes less evident, as happens for example when wine recover from shipping or bottling.[/quote]

You know Oliver, I hadn't really thought about that. If I catch your meaning correctly, you're saying that as a wine opens up and becomes more fruity, this quality would balance out, or mitigate, the tartness. The same wine, if very closed, might offer little more than the tart quality. Makes sense to me. Tom V

It could be simply that your taste accommodates to the acidity. If you taste anything that is a little acidic, over time it will seem less acidic than when you first started. You could test this by making sure you rinse your mouth with another liquid before each taste of the wine you are examining.

(If you have not tried it before it is very instructiive to taste a couple of wines in different orders. The differences are VERY noticeable.)