This edible berry grows in clusters on small shrubs or climbing vines in temperate zones throughout the world including Africa, Asia, Australia, Europe and North and South America. California is the largest U. S. producer of grapes — both for wine and for the table. There are thousands of grape varieties, each with its own particular use and charm. In general, grapes are smooth-skinned and juicy; they may have several seeds in the center or they may be seedless. There are "slip-skin" varieties, which have skins that slip easily off the berry — like a mitten being pulled off a hand — and those with skins that cling stubbornly to the flesh. Grapes are divided into color categories of white or black (also referred to as "red"). White grape varieties range in color from pale yellow-green to light green, and black grapes from light red to purple-black. They're also classified by the way they're used — whether for wine (such as cabernet or riesling), table (like thompson seedless or ribier) or commercial food production, such as muscat grapes for raisins, zante grapes for currants and concord grapes for grape juice, jams and jellies. Wine grapes, for instance, have high acidity and are therefore too tart for general eating. Table grapes, with their low acid, would make dull, bland-tasting wines. The availability of table grapes depends on the variety. Buy grapes that are plump, full-colored and firmly attached to their stems. White (or green) grapes should have a slight pale yellow hue, a sign of ripeness. Dark grapes should be deeply colored, with no sign of green. In general, grapes should be stored, unwashed and in a plastic bag, in the refrigerator. They will keep for up to a week, though quality will diminish with time. Because most supermarket grapes have been sprayed with insecticide, they should be thoroughly washed and blotted dry with a paper towel just before eating or using. Ideally, grapes should be served at about 60°F, so it's best to remove them from the refrigerator about 30 minutes before serving. Table grapes can be used in salads, for pies and other desserts and of course for out-of-hand eating. Whole grapes are also available canned. Grape juice comes in cans or bottles; grape jelly, jam and preserves in jars. Fresh grapes contain small amounts of vitamin A and a variety of minerals. See also catawba; chardonnay; chenin blanc; delaware; emperor; french colombard; merlot; muscadine; niagara; petite sirah; pinot blanc; pinot noir; sauvignon; Sémillon; sultana; sylvaner; tokay; zinfandel.