When Edward Lee was growing up in Brooklyn, his grandmother fermented traditional Korean foods at home to stock the pantry, making her own gochujang and doenjang, along with several kinds of kimchi and rice vinegars.
Lee now makes his own kinds of vinegar, using whole raw persimmons, peaches and fennel. Like many cooks who value the complex and sometimes unpredictable flavours of these homemade fermentations, Lee reaches for vinegar as an editing tool, using it to brighten and filter his dishes in delicate ways, boosting sauces and buoying broths.
He adds a glug of mushroom vinegar to a dish of smoked mushrooms with potato puree, just before it's served. He brushes fruity vinegar all over rib-eye steaks and pork after the meat has been browned and finished with butter.
"I use vinegar in everything," Lee said. "Not just vinaigrettes. The magic, transformative power of vinegar isn't in vinaigrettes."
The Food and Drug Administration in the US requires that what is labelled vinegar contain 4 or more grams of acetic acid per 100 millilitres. That acid, produced when certain bacteria metabolise alcohol, is what broadly defines vinegar and its flavour - the sharpness on your tongue, the prickling in your nostrils.
The word vinegar comes from the French vin aigre, or sour wine, but great vinegar can be made from the slow, controlled fermentations of many different fruits, vegetables, grains and syrups. They can be cloudy or clear, mouth-puckering or sweet, fruity or gamy, with endless variations.
"A great vinegar has all the characteristics of the initial product - that's the most important thing," said Harry Rosenblum, the author of the 2017 book Vinegar Revival.
Making your own vinegar isn't foolproof, but part of its appeal is that it requires little in the way of an initial investment, and few tools. (Though serious vinegar-makers may rely on pH meters and other gadgets, a wide-mouthed jar and a piece of cheesecloth are all you really need to get started.)
Vinegar, the result of acetic fermentation, simply requires oxygen, bacteria and alcohol. You can start the process with ready-made alcohol - a bottle of wine, sake or cider - or create your own alcohol by fermenting fresh peaches or coconut water. From there, the microbes get to work, turning the alcohol into vinegar.
In her Dallas apartment, chef Misti Norris ferments a jumble of vinegar in glass containers and covered oak barrels, in a dark, temperature-controlled nook equipped with a dehumidifier that keeps the vinegar around 65 degrees. Some will mature for a few months, others a year.
"I like to work on things that take a long time," said Norris, who runs the pop-up restaurant Petra and the Beast.
When she began making vinegar a few years ago, she was giving bottles away to friends in the restaurant business, but as the taste and demand for great vinegar have increased, so has Norris's production. She plans to sell her vinegar later this year, including some made from local grapes, passion fruit, peony flowers and figs, as well as collaborations with local brewers, made from sour beers and fruit-infused saisons.
In his book On Food and Cooking, science writer Harold McGee calls vinegar "alcohol's fate," neatly summing up both its process and history, which goes back as far as the making of wine, beer and mead.
The earliest vinegar were likely produced in the Middle East, somewhere along the Euphrates and Tigris rivers. Before refrigeration, there was simply no way to put the brakes on the fermentation process: Ripe fruit produced alcohol, then charged ahead in warm climates, turning to vinegar.
Michael Harlan Turkell, a writer and photographer who makes honey vinegar in his Brooklyn backyard, travelled the world researching the ingredient for his 2017 cookbook, Acid Trip.
"Vinegar probably wasn't a culinary ingredient until around 1500 B.C.," he said. Around that time, it was used not only as a preservative, but also as a flavouring agent, poured over noodles in China, and forming the base of dipping sauces.
Once vinegar made the leap, it persisted. Like alcohol, vinegar was refined all over the world in different ways, shaping cuisines as both a preservative and a flavouring. Where nipa palms and coconuts grew, vinegar could be made from sap and water. Where rice and sugar cane grew, it could be made from sake and juice.
When vinegar-makers get talking, they sound a little like wine lovers. They refer to the expression of the fruit, the structure of the flavours, the complexity of aromas in the nose.
"We're going from rotten fruit to this beautiful, flavourful, elegant acidic thing that you can drink," Lee said. After a decade of making vinegar from scratch, he added, the process remains somewhat mysterious to him. "Things are so scientific, and so standardised in the kitchen. We've figured it all out. But not vinegar!"
About 20% of the time, the vinegar doesn't work out, he said. A spore mold finds its way into the jar, ruining the entire batch. Or the liquid becomes too rich in ammonia or somewhat rancid-tasting, or everything turns the bad kind of moldy.
His cooks find vinegar's lack of certainty irritating, but for Lee, it only underscores his affection.
"Every time I make a vinegar and it works out, it's like a minor miracle," he said. "I'm over the moon."
Homemade Red Wine Vinegar
A 750-ml bottle of good red wine
1/2 cup live raw vinegar, or vinegar mother
* Pour the wine into a clean, wide-mouthed half-gallon glass jar. Put the lid on and shake it well to aerate the wine. Remove lid, and add drinking water until the jar is about three-quarters full, along with the live raw vinegar. Cover the jar with cheesecloth and keep the cloth in place with a rubber band.
* Leave the jar undisturbed in a dark place at room temperature for 3 to 4 weeks, checking regularly to see that a vinegar mother (a translucent, gelatinous disk) is growing on the surface, and no mold is forming. (If you see green, black or white mold, scrape it off; if it grows back, throw out the mixture and start over.) You will start smelling vinegar after a few weeks, and can taste it every week or so to monitor the fermentation.
* After about two months, when the alcohol has acidified, or when a taste of the vinegar makes your mouth pucker, it's ready to strain and bottle. (You can save the mother to begin a new batch.) The vinegar can be used as is, or aged in the bottle for up to a year to mellow its flavour.