The Best Red-Wine Vinegar You’re Likely to Find Is the One You Make Yourself

It Does Involve Some Acceptance of Nature

You don’t actually need a barrel to make vinegar, just a jar with a cloth cover. Edward Behr

[This is the first of a two-part post based on a piece I wrote long ago. Coming next: Practical advice about making your own.]

VINEGAR — PRIMORDIAL, AS OLD AS WINE — is one of the most important and least thought about components of good food. It needs restraint, but it might be used more often. It’s important above all for dressing salads (and sometimes cooked greens); it’s crucial in sushi rice. It makes many vegetable and fruit pickles, condiments, marinades (although in marinades wine is nearly always better). Vinegar takes a lead in a few dishes (French poulet au vinaigre and sauce piquante, Italian agrodolce preparations, including characteristic Sicilian dishes such as caponata). And vinegar added like a seasoning, almost like salt, plays an occasional subtle role in balancing and lifting dishes that are a little flat: a stew, a soup, a sauce. Each of the different vinegars made in different places has its own character — wine vinegar, cider vinegar, rice vinegar, malt vinegar, sherry vinegar. Lemon juice, especially, can serve the same purpose, but the most interesting of all the sharply sour liquids is red-wine vinegar. It has more depth, more nuance, more flavor to balance sheer acidity. The more aroma there is, the less the acidity is apparent.

Good red-wine vinegar has strong aromas of fruit, like the best fruit in wine. Better wine makes better vinegar. The desired qualities of red-wine vinegar come from the tannins and other elements in the grapes’ dark skins, which are generally squeezed hard in the press. But in light-colored sauces and most pickles, the dingy red color would be strange, so we use light-colored vinegars instead.

(You might think from the color of traditional balsamic vinegar, the real thing, that it’s made from red wine. And yet it’s not made from wine at all but from the boiled-down must — the freshly pressed, unfermented juice — of, usually, white grapes. The complex evolution takes place during years spent in barrels, and the final balsamico used to be consumed on its own; it had little or no role in food or cooking. That vinegar has nothing in common with today’s quickly mixed together sweet “balsamic” vinegars, which can be . . . simple, dirty-tasting. You’re better off with almost any non-sweet vinegar.)

Most commercial wine vinegar, although it can have fruit and floral notes, tastes thin because of the low quality of the wine used and the nature of the industrial process. Enormous vessels continuously circulate and aerate the liquid, sometimes producing vinegar in less than a day. The best-known device, the Acetator, made by the German company Frings, employs a submerged fermentation. Only one important species of Acetobactor is present, which narrows the flavor. And most commercial vinegar is pasteurized or sterile-filtered to remove bacteria; either treatment mutes flavor.

Still, you can buy reasonably good wine vinegar, although you may have to look outside a supermarket. Some safe choices come from top Italian wine properties, such as Castello di Volpaia and Badia a Coltibuono. From France, there’s Martin Pouret, the last mainstream producer never to have given up on barrels. There are good sherry vinegars from Spain. A slew of US small-scale producers has appeared; you have to taste and decide. Producers in various countries offer single-grape-variety vinegars to explore as well as interesting vinegars with added flavors that take up where the vinegar itself may leave off. And mass-produced North American cider vinegar is a relative bargain, better than most red-wine vinegar.

But sadly, really outstanding red-wine vinegar is seldom if ever for sale. The cost of the initial wine and the time required would push the price too high. Unless you’ve tasted very good homemade, you probably don’t know how good vinegar can be. If you use leftover wine (even scavenging it from abandoned glasses; the acidity will sanitize it) and put it an old glass jar, then your vinegar costs nothing. My best ever, a one time luxury, was made of leftovers from a tasting of expensive Burgundy. But even buying wine to make vinegar is a better bargain than buying good wine vinegar. Lately, I admit, I’ve been focused elsewhere and haven’t been making my own. I have a little backlog saved for special occasions, and thinking about the subject again is making me restart. There’s no substitute.

The best red-wine vinegar I’ve tasted is my own, but it’s not all on the same level. Most batches are good, and a few are so special that I treasure the bottles. Some batches, however, I throw out. They have a strong, unpleasant aroma of nail-polish remover, enough to make salad repulsive. It’s the single problem I’ve had in making vinegar. Rarely, I’ve found the same thing in a commercial bottle. What bothers me is not so much the waste, because the wine comes from the remains of bottles: I’m frustrated by my lack of control.

The method for making vinegar could hardly be simpler. There’s hardly anything to do. When wine is left open to air, a mother forms on the surface, a thin veil at first, scarcely visible. Sometimes it becomes powdery; often it turns into a thick mat — whitish, translucent, and slippery, like a tough, aberrant form of gelatin. In fact, it’s cellulose. The mother is the sign that bacteria of the genus Acetobacter are at work. They’re present in the environment, unavoidable, and often already in the wine. Gradually, they turn ethyl alcohol and oxygen into acetic acid and water. Acetic is the acid that defines vinegar (the word comes from French vin aigre, “sour wine”). Unless too much sulfur was added at the winery, the transformation is more or less inevitable when wine is exposed to air. That’s why wineries keep their barrels topped up and why boxed wine keeps its qualities until it’s all gone. Within a few months, and sometimes just two or three weeks, your vinegar is ready. Most of the wine’s fruit aromas have been destroyed because they have combined with oxygen; other aromas have disappeared into the air as vapor. Yet some of the good aromas are more durable, and rewarding new ones have formed. Vinegar keeps well, as a rule, in a full, sealed bottle, although eventually it loses its best flavor.

White-wine vinegar is made in the same way as red, although white wine often contains more sulfur, which makes it more reluctant to turn. (The sulfur is partly to protect the flavors from oxidation; red wine’s large amount of antioxidant tannin reduces the need.) You can make vinegar from any liquid that will first ferment into alcohol. Very good cider vinegar isn’t at all hard to make, if you can find freshly pressed, sweet juice that isn’t pasteurized and doesn’t contain preservatives. (It used to be the norm at US cider mills. Now, if you live where apples grow, you might have to be lucky and get invited to someone’s home cider pressing.) The sugar easily ferments at room temperature to form a moderate amount of alcohol — use a roomy container or it may foam over. Vinegar follows. I’ve never had any trouble making cider vinegar; the best comes from fully ripe apples with rich, sweet, but tart juice.

For a long time, I wanted to understand which chemical compounds were responsible for the good aromas — which higher alcohols, esters, aldehydes, ketones — and how they came about. But the studies hadn’t yet be done. Now that they have been, I realize I don’t care, because it doesn’t make any practical difference. What matters is the raw material.

I do want to understand more about what causes the nail-polish aroma. After a while, I suspected the culprit was ethyl acetate, which I was somewhat familiar with in wine. It’s part of volatile acidity, which is a wine defect, at least beyond a barely perceptible trace in more rustic wine. The main component of volatile acidity is acetic acid, but the most obvious one is ethyl acetate. I bought a pure sample of ethyl acetate from a scientific supply house, and the aroma was in fact identical to the one in my problematic vinegar. Ethyl acetate forms when ethyl alcohol combines with acetic acid, which happens when the two are together during a slow natural acetic fermentation. In very limited quantity, ethyl acetate is an essential part of vinegar flavor.

But why do I sometimes end up with too much? One variable is that the initial wine or cider is always different. And the acetic bacteria surely behave differently in response to that material, to the season, and who knows what. They’re certainly more abundant and lively in summer. I believe that less ethyl acetate is produced when the acetic bacteria thrive and complete the transformation fairly quickly, in one to two months. That happens when the ambient temperature is relatively warm, and it must help to use organic wine with little or no sulfur.

Also, acetic bacteria struggle in liquid that’s too alcoholic. You can read that 9 percent alcohol is a maximum, and above that you should dilute the liquid with water. But I’ve rarely diluted the wine I use. And what does it mean that I completely forgot, for years, a bottle of vodka from a small distillery (I don’t drink much vodka) in the back of a floor-level cabinet? I rediscovered it and saw the liquid had turned amber. I’m always curious about the effects of time and decay. I smelled, and then I tasted. The vodka against all the odds had become vinegar, somewhat mild and very good. (A few more years have gone by, and the last of that vinegar is still in the cabinet. I just tasted it; it’s still very good.) Another time I left a small amount of red-wine vinegar untouched in a bottle for months and saw that a gray-brown powder had appeared on top. The liquid beneath was perfectly colorless. I tasted it. The vinegar had turned to plain water with no flavor at all — acetic bacteria are capable of that. They’re a little inscrutable, never entirely predictable. There’s a limit to how much you can control nature. ●

[Coming next: Practical advice about making your own.]