wine aging

I've seen it happen far too many times; well-meaning but naive wine customer buys the oldest bottle of red she finds on the shelf, keeps it in her basement for a couple years, and cracks it open at that "special" occasion only to find it's turned to a brown, sour, nasty liquid, fit more for drizzling over a salad than washing down a perfectly grilled porterhouse.

Stupid Wine, she thinks, It Must Be Corked, and proceeds to haul it back to the wine store, several years after purchase, and angrily demand a refund for the embarrassment suffered, at which point it is now My Problem and frankly I've got enough on my plate as it is.

It certainly doesn't help that the popular conception of wine out there, especially red wine, is: the older the better. The irony is that, the very fact that wine today is so popular is why winemakers churn out millions of bottles of fresh, young, fruity wine that's ready to drink now and not even remotely shelf stable - whilst simultaneously selling the classy, refined notion of aged wine with fine cuisine. It's classic bait-and-switch marketing. 95% of all the wine on store shelves will not last 5 years past its vintage date. So today you're going to learn about how wine ages; how exactly it changes and why, which wines age and which don't, and how to be a savvy consumer and not get ripped off like Fat Freddy trying to score a lid, cause honestly if I get one more ill-informed customer with deep pockets and a reputation to uphold I'm going to snap. So make sure it's not you.

Aging Gracefully

Just like people, most wines get worse with age; we can't all be like Meryl Streep, alas. Oxidation is the main culprit - even with screw-top caps, ever classy, tiny amounts of oxygen still seep in over the years. Phenolic compounds present in wine are easily corrupted by only small amounts of oxygen, and even the alcohol itself will break down into acetic acid. However, complete lack of exposure to oxygen is just as bad, resulting in a harsh, young, bitter wine that never develops. Controlled oxidation, one of the primary reasons wine is aged in oak barrels, is key. Part of the reason French Oak is so legendary is because of its tight grains, which allow only minute amounts of oxygen through meaning the wine can sit in the barrel for sometimes years, absorbing its aromatic compounds to the fullest without spoiling. American oak, with wider grains, is the better choice for quick maturation.

(It should be noted that with wine, the exception is often the rule; hence some wines, Madeira in particular, are intentionally oxidized, a process called maderization.)

So with that in mind, I will list the three main characteristics of a wine that promote longevity, or to put it another way, the characteristics that prevent excess oxidation*. Typically for a wine to age at all it must contain two of the three, and for the real long-lived brutes, your 1948 Chateau Petruses and Barolos, it's all three or bust.

Acid

Typically present in greater quantities in white wine, acid is that puckery quality that promotes salivation and so is technically considered, along with alcohol, a softening agent in wines. Heat, sunlight, and ripeness all determine the acid level of a wine, so a general rule is that cool climate grapes, like Riesling and Sauvignon Blanc, will generally be higher in acid than, say, Chardonnay or Muscat, white wines that thrive in warm, sunny climes. For a winemaker, getting the acid levels right is crucial, and a delay in harvesting of even a couple days can make the difference between stellar wine and table wine. Too much acid, and the wine is green and unpalatable; but wait a little too long, and an overripe grape will be flat and one-dimensional. Pinot Grigio is notoriously difficult to judge in this area, as it ripens late but is fragile, and so is susceptible to early frost and rot.

The red grapes that are highest in acid, Cabernet Sauvignon and Nebbiolo (which produces Barolo), typically make the wines able to age the longest. Though white wines are plentiful in this regard, they often lack the next two qualities making them unsuitable for long-term aging. A good rule with white wines (in particular Sauvignon Blanc, Pinot Grigio, and Gewurztraminer) is to drink them within three years of the vintage date. Any more and you're playing with fire, though there are exceptions, which I will get to below.

Grapes that are high in acid: Cabernet Sauvignon, Nebbiolo, Riesling, Gewurztraminer, Chenin Blanc, Sangiovese, Sauvignon Blanc.

Tannin

Present in the skins, seeds and stems (called must) of grapes, Tannins are exclusively found in red wines, due to the fact that the juice is allowed to ferment with the must as opposed to white wines where the juice is removed. (A common misconception is that white wine grapes are actually white; Pinot Grigio grapes, for example, can often be a bright purple colour). Rose wines, as you may have surmised, achieve their colour by only limited contact with the must - hence "white" zinfandel. Ripeness and skin thickness are typically the determining factors for how tannic a wine will be; nebbiolo is a very late ripening red grape and so must be harvested somewhat unripe to prevent frost and vine rot, despite the searing tannin and acidity levels that result. Pinot Noir, on the other hand, though being another late-ripener, has very thin skin and so is not particularly tannic (save for those grown in the village of Pommard in Burgundy, for reasons yet unknown).

Not all red wine contains tannin. Beaujolais, for example, is almost devoid of tannins due to its anaerobic fermentation process (called carbonic maceration). Valpolicella, a light, summery Italian red, is the same way. The popular reds Merlot, Shiraz/Syrah and Zinfandel all contain moderate amounts of tannin.

Anyways. As red wine ages, the tannin molecules present inevitably smash together, which causes them to fuse. When they get big enough, they fall to the bottom of the bottle as sediment. This is why so much value is placed on aging - as more tannins are converted to sediment, the remaining wine becomes much softer, intensely fruity, and elegant, without sacrificing body or acid. After all, you could produce a soft, fruity wine by harvesting late and reducing pruning, but it would be thin. That's why Barolo, containing the savagely dry nebbiolo grape should only be drank a minimum of ten years after the vintage date. Any earlier than five years it's literally undrinkable, because it takes that long for enough tannin molecules to collide together and fall as sediment.

Grapes that are high in tannin, from most to least: Nebbiolo, Cabernet Sauvignon, Syrah, Zinfandel, Merlot, Malbec, Tempranillo, Pinot Noir, Sangiovese, Barbera, Valpolicella (actually Corvina and Rondinella grapes), Beaujolais (actually called Gamay).

Extract

Also called fruit concentration, extract refers to how many fermentable solids, such as pulp, are present in a grape. This is why most vines are aggressively pruned and trellised; the less fruit a vine produces, the more concentrated and hence flavourful it will be. It's also why, rather counter-intuitively, vines are often planted on poor, gravelly, chalky soil; the prevailing notion, developed over millennia of winemaking, is that a vine must struggle to produce fruit - a pampered vine growing in rich topsoil will get lazy and produce less-than-stellar grapes.

High-extract grapes produce highly alcoholic wines, which help guard against oxidation, as well as full-bodied, broad-shouldered wines which fill the mouth and linger for seemingly eons. Zinfandel is perhaps the best example of this, producing wines often in excess of 15% ABV and presenting a very rich, blackberry-infused palate, though white wines such as Muscat, Riesling and Chardonnay also exhibit the same qualities. Extract levels are usually more influenced by the intrinsic qualities of a grape and less by environmental considerations.

High-extract grapes: Nebbiolo, Cabernet Sauvignon, Muscat, Riesling, Zinfandel, Tempranillo, Viognier, Tokay

Other Considerations

There are about a million other things that influence to varying degrees the shelf life of a wine - vinification practices, type of oak used for aging, whether or not sulfites are added, what time of day the fruit was harvested, how it's stored, how much sunlight the bottle is exposed to, ambient temperature, the zodiac sign of the purchaser, you name it. The idea here was simply to present the primary factors in aging. Truthfully, you could devote a lifetime to oenology and still not be 100% sure. Winemaking is, after all, as much art as science.

The importance of proper cellaring cannot be overestimated. All wine, if not meant to be drank within a few months, should be stored lying on its side in a cool, dark place. Why on its side? It keeps the cork moist and the liquid provides a better airtight seal.

Sulfites

Sulfur compounds, particularly sulfur dioxide, are used by winemakers at various stages of the vinification process as a preservative. It's a misconception that red wines have the most sulfites; in reality, the reverse is true, with most white table wines containing three to four times (+/- 150 ppm) as many sulfites as your average red. This is because white wines typically have a shorter shelf life than reds, which is the primary purpose of adding sulfites. So you can't blame sulfites for your red wine headaches. Fortified wines, with their large amount of unconverted sugars, have by far the highest sulfite levels with some going as high as 450 ppm.

Virtually every bottle of wine has on it, somewhere, the words "contains sulfites". That's because the legal threshold in the United States requiring such a statement is a miniscule 10ppm, even though studies have shown that the threshold for sulfite-related reactions starts at roughly 200 ppm. Basically all grapes have that many naturally occurring sulfur compounds even if nothing extra was added (such as with organic wine), so the label "contains sulfites" is not particularly instructive. Some winemakers have started adding "no added sulfites" to their label, which is at least a little clearer.

tl;dr. Just tell me what to buy

Ok. Here are the most commonly found wines for sale, in descending order of longevity from vintage year (standard disclaimer applies).

1. Madeira - up to 200 years (seriously. 1795 Madeiras are still sold at some restaurants)
2. Port, very high-end Bordeaux, top Champagnes (but it will be flat) - around 50-80 years
3. Barolo - around 30-50 years
4. Mid-to-upper-range Bordeaux, Amarone, Brut champagne - 15-20 years
5. Riserva Chianti, Reserve Cabernet Sauvignon, High-end Riesling, good Burgundy - 10-15 years
6. Gran Reserva Rioja (Tempranillo), lower/mid range Bordeaux, Chateauneuf du Pape - 8-12 years
7. Mid-range Cabernet Sauvignon, heavily oaked Chardonnay, mid-range Riesling - 6-8 years
8. Reserve Malbec, Chianti, Barbera, Australian Shiraz, high-end Merlot - 5-6 years
9. All other red wines - 5 years or less
10. All other white wines - 3 years or less

Most popular wines today, white and red, suffer from the same problem; overproduction. Casual wine drinkers prefer soft, light, fruity wines that don't demand a lot of attention, and so winemakers scramble to fit the bill. This means late-harvested, high-yield grapes aged in concrete or stainless steel vats, which gets the flavour profile people like but also makes the wines very short-lived. To shorten the maturation process, many winemakers age red wines in vats full of oak chips, imparting the qualities of oaking at a fraction of the time or price of doing it in proper casks. Pinotage, the in-grape of South Africa, is highly susceptible to rot and so is aged in extremely charred oak chips to mask the flavour of spoilt grapes. Wine producers then turn around and market it as tasting like mocha. Which it most certainly does.

Wine is absolutely amazing, and can offer a lifetime of decadent enjoyment. There's nothing wrong with approaching it with an open mind an a willingness to learn, and indeed it's only by drinking wine, lots of it, that the learning process happens. What's important, though, is to be humble - the more you learn about wine, the more you realize just how absolutely infinitesimal your knowledge of it really is.

So don't make an ass of yourself at the wine store.