I am trying to better understand how wines will evolve over time, and acidity is a topic that confuses me a little bit.
My novice understanding is that acidity remains unchanged over the life of a wine, while fruit and tannin will fade away over time. This would lead me to think that wines will all eventually turn into acid bombs… and I have read commentary as such on CT (‘fruit and structure gone, just acid left’). However, reality is different… many wines can go decades without turning into acid bombs. Some have pointed me to alto piedmonte as wines that taste high acid in their youth, but more mellow with 20-30 years of age on it (I have no primary verification as the only two bottles of aged alto piedmonte were likely flawed). And some have postulated that 2013/2014 burgundy will end up better than 2015 over the long haul given higher starting higher acidity, which won’t detract from their drinking enjoyment 20 years out as acidity will mellow out.
So accordingly, what about the statement (“acidity remains unchanged over the life of a wine, while fruit and tannin will fade away over time”) is false or requires nuance? And if acidity is unchanged, why does the perception of acidity change over time? And does this have the effect of adding sweetness to a wine, especially for a wine that may feel too acidic or tart in its youth?
First and foremost, the perception of acid is not perfectly correlated with the measurable acidity. Your perception of acidity is influenced by the amount of fruit in the wine, and by the tannins and any residual sugar. High acid “dry” wines can be softened by a bit of residual sugar, as many are in cool climates such as the Loire and Germany. So even if acidity doesn’t markedly change with age, the perceived level of acid may.
It can be hard to distinguish tannin and acidity in some wines. So what you perceive as acidity may, in part, be tannins, which do soften in most cases.
Some high acid wines (e.g., Burgundy, nebbiolos from Northwest Italy, some Northern Rhone syrahs) can develop a kind of sweet fruit with age that balances out the acidity that may have been conspicious young. This is counter-intuitive, since it’s more common for wines to show their fruitiness when they’re young and then shed it. That ability of some wines to flesh out (I have no idea why) can make them more approachable and seem less acidic with age.
As for the view that '13 and '14 Burgundy may evolve better than '15, I assume that’s because '13 and '14 were less ripe years. Often some definition and aromatic complexity is lost when fruit is particularly ripe, and not just in Burgundy. I assume that’s what people are talking about. I’d guess that the view you describe has less to do with acid itself and the ability of those vintages to remain sound in the bottle and more to do with the likelihood that the '13 and '14 wines will ultimately be more interesting. (But I’m surmising since I don’t know the statements you’re referring to.)
I think you put your finger on it, and this is my hypothesis as well. Wines will form tertiary fruit over time, which though it tastes like fruit, has nothing to do with the fruitiness of youth. The emergence of this tertiary fruit somehow hides acid, and that is precisely what makes really old Bordeaux and Nebbiolo (which is notoriously high acid) sing
I thought that there are two (or more?) different kinds of acids in wine, one of which fades/softens over the years and one which stays more consistent…
EDIT: Winefolly states the following: “Often, during the aging process a wine’s malic acid is converted to lactic acid (in a process called Malolactic Fermentation) which results in a smoother, less tart tasting wine.”
That quote is referring to aging in the winery, pre-bottling. It’s intentional, and also eats up nutrients that could otherwise allow funny stuff to happen in the bottle. Most reds have gone through MLF prior to bottling. It’s not desirable to allow it to happen in bottle, since it would be an unpredictable occurrence involving random bacteria strains that can produce all sorts of off flavors.
Wines with a lot of malic acid tend to have a significant grapefruit note (though it’s not the only source of perceived grapefruit).
The list of acids in wine is very long, but those are the main ones at play in the must, along with tartaric and citric. Tartaric is often added to increase acidity, since it’s the most neutral in effect and least reactive.
Tartaric is the acid we often see settling out of a wine into tartrate crystals. That does increase pH a little. Winemakers can cold stabilize a wine prior to bottling, which will allow the tartrates that “want” to settle out to do so.
The main factor here is perception. As noted above, tannin can greatly increase the perception of acidity.
In which cases? Because I find them so distinct that there’s no way to confuse them, but obviously many other people do (for example every now and then one comes across TNs in cellartracker of Barbera commenting on its aggressive tannins etc.).
For those who struggle to differences: acidity is the stuff that gives the wine its tart, crunchy qualities. That lemony sharpness in whites and tangy fresh cranberry / lingonberry character in reds. Higher acidity makes your mouth salivate, often accentuating the “juicy” quality of wines.
Tannins are the things that give wines their astringency, i.e. make them dry your gums up, turning mouth like sandpaper.
Wines low in acidity and low in tannins are flabby and lacking structure. Light-bodied wines (like some lower-acidity Poulsard wines) can be enjoyable, but full-bodied wines are often just fat and dull.
Wines low in acidity and high in tannins might feel soft and lacking in structure, but still can come across as firm and muscular at the same time with chewy texture and noticeably mouth-drying character. Some Madiran wines or new world Cabs without acidity adjustments are good examples.
Wines high in acidity and low in tannins are like Barbera. Tart, dry and crunchy but never grip your gums no matter now long you slosh the wine around your gums.
Wines high in acidity and high in tannins are like Nebbiolo or Xinomavro. Tough, structured and muscular. Have freshness and still tons of power.
The only examples I can think of where the wines might be high in acidity or in tannins but without tasting like it are sweet wines that mask their acidity well and extracted red wines that have lots of very ripe and mellow tannins that don’t really offer any grip, only textural mouthfeel with the increased dry extract.
Yet even these cases don’t have anything to do with confusing acidity with tannins. I’ve experimented with adding powdered tannins to wine and only when the amount exceeds that what is possible in even most tannic wines like Sagrantino and Tannat add the tannins such bitterness that it could be mistaken for tartaric/malic/lactic acid. However, that is such a corner case I doubt any wine will be similar. One would really have to taste tannins or other wine acids really differently from how I taste them to actually confuse them.
There are a handful of acids in wines, but the three key acids are tartaric acid, malic acid and lactic acid. The grapes contain naturally tartaric acid and malic acid, not any lactic acid. Malic acid tastes like sharp green apples (apples are high in malic acid, hence the name: malus = apple). Lactic acid is softer and it is the one that gives the sourness to yoghurt and other sour milk products (hence the name as well). With malolactic fermentation (MLF) a winemaker can soften the acidity (raise the pH without changing the molecular weight of the acids in the wine) of the wine by transforming the sharp malic acidity to lactic acidity; however, if the grape variety is high in tartaric acid and low in malic acidity, MLF has very little effect in the pH of the wine.
Winemaker can reduce tartaric acids in a number of ways, of which “cold stabilization” or “cold filtering” is pretty familiar to most of us through the wine crystals i.e. crystal tartrates, as Wes noted above. Since the solubility of tartaric acids decrease with temperature, some of the tartaric acids drop out of solution as crystals as the wine is chilled down and they don’t dissolve back into the wine again.
And it’s the acid that already exists in the wine. Citric acid exists in grapes, but in very small quantities (only a few % of the total acidity) and remains in bottled wines mainly in wines that haven’t undergone MLF, since many lactic acid bacteria (LAB) convert citric acid either to malic acid or acetic acid (VA). Many producers don’t prefer citric acid since it is microbiologically less stable (if there are any sound LAB in the wine when the acid is added, they can convert it to VA) and it is quite conspicuous. I’ve tasted many inexpensive Australian Shirazes and other red wines that are atypically fresh with a weird lemony tang to them. It’s quite obvious they’ve seen acidity corrections and the citric acid really sticks out.
The main factor here is perception. As noted above, tannin can greatly increase the perception of acidity.
Is that so? I’ve understood it’s vice versa: the pH of the wine can influence greatly the astringency of the tannins. To my understanding, tannins don’t change how acidity is perceived.
No need to lecture me on the nature of tannin and acid. In theory, the tartness of acid is distinct from the astringency of tannins. But in practice, they can be hard to distinguish in some wines. For starters, there are different kinds of tannins. Second, as Wes pointed out in the line you quoted, the perception of acidity is not independent of tannin levels.
Thank you for all the conversation and thoughts. Summarizing thus far (as I understand it):
Tannin increases the perception of acidity. As tannin soften, that will decrease the perception of acidity.
Certain wine varietals (all?) have a change in fruit profile over time. This fruit profile can be more sweet or tertiary, and may be due to “subtle oxidation of elements of the wine” (but no one really knows why this happens as the sugar level of the wine itself will not change in the bottle). This change (a perception of sweetness/acquired tertiary notes), also has the effect of decreasing the perception of acidity.
I think that’s a pretty good summary, except that I’m not sure that the subtle sweetness that develops in some wines that seem acidic young is due to some form of oxidation. (That was just a question that James posed. I don’t see anyone here substantiating that.) The fleshing out I’m talking about certainly isn’t like the sweet caramelized flavors of some older wines. It’s a fresher set of flavors.
There are lots of things going on chemically as a wine ages, not just processes involving oxygen. Wes might be able to give a better explanation of how this can happen.
To return to your original question, some wines do have too much acid, though it may not be apparent when they’re young. In some cases, the acid comes to the foreground with age as the fruit dries out, even though the tannins have softened. Many people suspect this is an issue with 1996 red Burgundies, though they seemed to have the fruit concentration to balance their tannin and acid when they were young. (Since I own a bunch, I’m keeping my fingers crossed . . . . )
Re sweetness “developing” in maturing wines, I’d guess in most cases that’s just a perception thing. Tannin resolves to the point that small degree of sweetness is no longer masked. There’s also the illusion of sweetness in some wines due to aromas we associate with sweetness. If the wine’s mouthfeel “plays along” with that, we might not notice it isn’t actually sweet.
As a footnote/digression to emphasize how hard it is to draw hard and fast rules about the structure needed for long aging. . . . . A friend brought a 2000 Dom. de la Vieille Julienne Chateauneuf to dinner on Saturday. It was silky smooth, with completely resolved tannins and no acid to speak of (from a perception standpoint). 2000 wasn’t an outstanding vintage in CdP, yet this was very fresh – pure pleasure. Who would have thought a grenache like that would be in such a nice place after 19 years? It was one of those wines that seemed to levitate without any supporting structure. (It was marked at 13% or 13.5% alcohol, which no doubt is one of the reasons it isn’t out of whack.)
I apologize, since I never intended to lecture you on tannins and acidity, since I consider you to be among the most knowledgeable people around here and I never assumed you wouldn’t know the difference. My short “lecture” was aimed for people who have less knowledge on the subject and I tried to make it clear with the very first sentence.
However, I’d really love to read more about the perception of acidity not independent of tannin levels. I’ve read in many places that it’s vice versa - tannins can be perceived differently in different pH - but I really haven’t felt acidity appearing different as the tannic profile changes, nor have I read any articles on the subjects. On the contrary, with my experiments of dissolving powdered grape tannins to a rather neutral wine with moderate acidity and no perceptible tannins (a Beaujolais), the perception of acidity didn’t change at all while the tannins became more and more pronounced with every addition, until the wine became almost undrinkably astringent and bitter.
And yes, I am well aware that there are different kinds of tannins and also that they change over time as the wine ages.
Often when your receptors are overwhelmed by something your perception goes off the charts, so to speak. You get too much of a taste or tactile sensation, you can no longer perceive it for what it is. Like a curve spiking to infinity. Like screaming feedback. Too much of a taste you like can, instead, taste unidentifiably “chemically” and unpleasant. Food too spicy hot for you can wipe out your ability to taste or smell, while perhaps coming across as extremely bitter-ish chemically. To another person, the heat in that dish can “bring out the flavors”.
In my kitchen experiments I’ve noticed this. Simple diluting can bring something back to where you can perceive it for what it is.
A pertinent example is my '08 plum wine. I used to make one every year and include a small percentage of cherry plums, which have thick tart tannic aromatic skins that lend a sort of Petite Verdot aspect to the wine. In '08 there was a bumper crop of those little things, so the percentage doubled to about 6%. It tasted great fermenting, but couldn’t make bottling due to a harvest conflict (friend’s VIP helpers could only make that day, so he didn’t want to change it). When I tasted a bottle, I found it nearly undrinkable. It wasn’t perceiving tannin for acid, it was the two playing off each other. The significant acid (same level every year) seemed like way too much. It took a year to mellow out. When the tannins dropped off to an acceptable level, the acidity was right for the wine.
Certainly. For example wines that are simply too sweet with sky-high levels of residual sugar seem to be not just sweet, but even a sort of “burning” feel (without any sensation of heat) when taste receptors seem to get overwhelmed by the glucose.
A pertinent example is my '08 plum wine. I used to make one every year and include a small percentage of cherry plums, which have thick tart tannic aromatic skins that lend a sort of Petite Verdot aspect to the wine. In '08 there was a bumper crop of those little things, so the percentage doubled to about 6%. It tasted great fermenting, but couldn’t make bottling due to a harvest conflict (friend’s VIP helpers could only make that day, so he didn’t want to change it). When I tasted a bottle, I found it nearly undrinkable. It wasn’t perceiving tannin for acid, it was the two playing off each other. The significant acid (same level every year) seemed like way too much. It took a year to mellow out. When the tannins dropped off to an acceptable level, the acidity was right for the wine.
But are you sure it was because of the tannins? (AND are you sure it didn’t go through MLF? )
Jokes aside, it can be something else than tannins that are making the acidity feel high. First of all, acidity does change over time. The molecular weight doesn’t change, i.e. if you take a chemical analysis of the wine, the dry extract of a wine doesn’t change as it ages, but acids can combine with other molecules over time, changing the perception of acidity. Secondly, some esters not only lend smell and taste to the wine, but they can also boost different components of a wine, including acidity, so that when young (still full of fermentation esters) acidity can stick out quite badly, but as the esters break up or blow off, the perception changes.
I’m not saying tannins couldn’t increase the perception of acidity, it’s just something I haven’t heard or read of before.
And by the way, how come the acidity remains at the same level every year? In Mosel the TA of a Riesling can be almost doubled/halved even in consecutive vintages. Only if you adjust for the acidity and check it out that makes sense, otherwise you can never trust fully what the plants give you.
I think that with most wines the answer is this is why most wines need to be drunk before the fruit fades. It is really only the types of wines many of us drink that age well. The reason IMHO is that with these wines the fruit does not fade as much as change its flavor characteristics from overt fruitiness to a combination of fruitiness and other flavors many call tertiary characteristics. On any great aged wine, there is a combination of fruit, acid and other tertiary characteristics so that you are not just left with acidity.
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