During our Wine Vault wine dinner, a solo diner cornered me for a game of Stump the Vintner. He stared me down, looked me flat in the eye, and asked, “Why do all of my California pinots taste like mush after 5 or 10 years?” One could answer this loaded inquiry any number of ways, but I chose to be diplomatic. I’d already floundered once when I quipped to a dermatologist, “so I guess you save lives every day.” Apparently he hadn’t seen the Seinfeld episode. He didn’t buy a bottle of Bruliam either. “Well that depends…” I began. Rather than hedge, I went straight to tactic #217 - Play Dumb. “Well I don’t know for sure, but I can offer a guess.” Since this gentleman was also a doctor, I tossed in some science vocabulary for gravitas. Then we talked about the biochemistry of wine aging.
A number of factors influence how quickly or gracefully wine ages in the bottle. Closure type, storage temperature and its consistency, acid content, varietal, and sanitation at bottling act collaboratively. Take the worst case scenario - a wine with leftover sugar bottled “organically” without added sulfur and stored in the sun. You’re incubating a petri dish. (Have at me organic-anti-sulfite police. Tie me down with homemade hemp rope and flog me with sustainably grown broccoli rabe). But what I am really talking about is oxidation - the chemical reactions that age wine in the bottle. Chemical components inside the wine react with one another and their end products can change the way a wine smells, tastes, or feels in your mouth. I called it “oxidation,” so of course oxygen is a culprit. You all know that when you leave an open bottle of wine on your kitchen counter for a few days, you get vinegar. This is the extreme. But no matter how meticulously your wine is bottled, an itsy bitsy amount of oxygen inevitably fills the headspace before closure. And if you’re bottle is closed with natural cork, there is a slow, steady ingress of oxygen until the bottle is opened and consumed.
Oxygen cannot act alone; he needs another chemical to bully. Oxygen pushes around phenol - a multi-ring shaped compound dripping with electrons that are easy to pick off. Like some douchebag in a bar who downs a few beers before picking up strange women, oxygen needs fortification too. Oxygen incorporates extra electrons that make him feel “super” powerful and “super” strong. Oxygen wearing extra electrons is named superoxide or peroxide-radical. Charlie Sheen lives with strippers and considers himself super radical too. When super oxygen craves more electron power, he swipes them from the phenols. The poor phenols don’t feel so super. After losing a few electrons, they turn brown. That’s why old red wines have that rusty, brick red hue. Cork dorks call them “oxidized.” But you can call them beat up.
Since you now know all about the oxidation of phenolate → semiquinones → quinones, let’s add another dimension. Losing electrons is humiliating, and the oxidized phenols feel naked and embarassed. A couple of half-naked semiquinones, down an electron each, will hook up to make their single electrons a pair. When half naked semi-quinones seek modesty by cowering behind a buddy, you call it “regenerative polymerization.” Truth be told, sometimes an oxygen would rather prey on this new chemical than beat up phenol again. This is one way a wine preserves its phenols, through oxidative reactions that make bigger, better and more attractive compounds from its original building blocks. Over the course of wine aging, various phenols, phenolates, semi quinones and quinones stick together making bigger compounds. More than 10 subunits make a polymer, also known as a tannin. “Tannin” is not specific to any class or group of chemicals. It’s just the big umbrella term that describes long, bulky phenol agglomerations. Two key ideas to consider here: 1) wine tannins are the chemicals that make your mouth feel dry, coarse, puckery, and sand-papery when you drink certain varietals, and 2) sometimes tannins get so bulky they precipitate. That’s the dark brown sediment at the bottom of your wine bottle.
I am now going to show you some pictures. These cartoons are supposed to be conceptual. Don’t worry about the details.
This is a phenol.
Here are two of them stuck together, sharing electrons so they feel less naked. Note the bridge between them.
Now imagine a whole bunch of these stuck together in different configurations. The possibilities are endless.
Kind of looks like the Millennium Falcon, doesn’t it?
But what does it all mean? Young wines with lots of single phenol molecules can taste sharp, astringent, or harsh. Over time, as the phenols condense into long tannin chains, the wine tastes “softer,” “rounder,” and more “supple.” Clearly a little bit of oxygen is a good thing. In fact most red wines get better with some oxygen additions - just not too many.
Wines with lots of tannin can handle their oxygen better than those with a lower tannin composition. Whether wine is a tannic heavyweight or not is largely dependent on varietal. Winemaking techniques can extract more tannin for sure, but grapes like zinfandel or pinot noir just don’t have as much tannin to begin with. That’s because they are thin-skinned. Just like some overly-sensitive, pimple-popping, low tannin doctors. Except pinot noir is literally thin skinned. Tannins come from grape skin so varieties like cabernet sauvignon which have thicker skin contain more phenol than the thin skinned guys like pinot or zin.
Coming full circle, this might explain why this guy's pinots seem “mushy” after 5 or 10 years.
It’s also possible the guy buys cheap drek and “cellars” it in the closet next to the water heater.