In the spring, grapevines start to sprout shoots, then leaves that, over the course of about six weeks, grow to approximately the size of a human hand. Leaves meant for cooking are best picked while they’re still tender, in late spring or early summer.
After a vine flowers in the late spring, grapes start to grow in a process called fruit set. Forty to 60 days later, the grapes start to change color (this is called veraison). Grapes are ripe enough to harvest anywhere from 30 to 70 days after veraison.
To help concentrate a vine’s nutrients, winemakers often trim unripe grapes. Some press the juice from these grapes to make verjus, a pleasantly tangy condiment that’s a great alternative to vinegar, because it’s less tart and easier to pair with wine.
Grape juice must be pasteurized and treated with sulfites to keep it tasting fresh. Most juice is made from table grapes, like Concords and Thompsons, but new juices are pressed from wine grapes, like Didier Goubet Merlot de Bordeaux Organic Grape Juice ($15; napacabs.com).
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Roughly 80 percent of the world’s grapes become wine through fermentation, in which yeast converts the sugars into alcohol. The cooler the temperature, the longer fermentation takes. Red wines usually ferment in a few days; whites can take weeks.
Prolonged exposure to oxygen will eventually transform any wine into vinegar. Artisanal vinegars tend to be fruitier, milder and more complex than supermarket varieties. California’s O Olive Oil makes single-varietal vinegars, like Pinot Noir and Zinfandel ($12; ooliveoil.com).
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Since raisins have so little moisture and so much sugar, they rarely spoil. Most raisins are made by setting grapes out on trays to dry for two to four weeks. Raisins still on the vine are fruitier and softer than those that come in a box ($6 for 4 oz; murrayscheese.com).
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Grappa, a clear Italian spirit served as a digestif, is made by distilling grape pomace (the skins, seeds and stems left over from winemaking). The best versions, like the elegant Alexander Grappa, are fragrant and nuanced. Oak aging can help soften and sweeten the fiery spirit.
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