BEFORE YOU TASTE, you tour a winery -- or are at least offered a tour. This isn't so much an exercise in delayed gratification as a way to enhance the enjoyment to come. You learn to appreciate the labor involved and discover why some wines taste better -- or at least different -- than others.

Here's a wine-tasting taste:

Before you enter the winery, you'll see the vineyards, almost always on a south-facing slope. According to Bob Harper, co-owner of Naked Mountain Vineyard & Winery, the roots of these hardy vines can go 30 feet deep and 75 feet out. And unlike other crops, they don't mind dry weather.

Although bunches of recently harvested cabernet franc and sauvignon (red wine) grapes were visible in open vats last weekend, most area wineries concentrate on white wines. "With red wine vines, you have to wait three to four years before you have grapes, and seven to 10 years before the wine tastes OK," explains Bud Hufnagel, general manager of Piedmont Vineyards & Winery. "It's similar to rose bushes: The older they are, the prettier the flowers and the better they smell."

The wine-making process requires cool temperatures, so most operations are below ground. When you walk down the stairs to a cellar, you're greeted by cool, damp air and a spicy, slightly vinegary grape aroma. At Naked Mountain, the grapes are pressed seven times through a stainless steel sieve -- lightly. The juice is then chilled to clear out solids "so you can take a glass and read a newspaper through it," Harper says.

Wine goes back and forth from steel tanks for chilling and filtering to wooden barrels for fermenting and aging. Seyval wines, almost unknown on the West Coast, spend the least amount of time in oaken barrels. Linden Vineyards ages its seyval only in steel vats. "That gives it a crisp taste; it's meant to be drunk young and fresh," says co-owner Jim Law.

The barrels, which lie on their side in neat rows, are selected for what flavor they will impart. French oak cooperage is thought to be the best; a barrel will be marked to show which of nine designated forest areas of France it comes from and to which of three degrees the wood was toasted, or cured over fire. "The darker toast gives more of a butterscotch flavor," Harper says.

Once the bottles are sterilized, the aged and filtered wine can be added. The corking machine at Linden cranks out one case a minute. The stoppers are from Portugal; the bottles from Mexico and New York.

When you're done with your questions, the winemakers will already have a selection of wines for you to taste. The few wineries with older red wines are sold out -- and last year's vintages may not be ready -- so be prepared to taste a flight of white wines, usually progressing from dry to sweet. You'll be served anywhere from two sips to a third of a glass, depending on how many wines the vintner has available for tasting; if you're toying with the idea of buying a particular wine, you can ask for a second taste.

Most wineries supply crackers, some with cheese, to nibble between wines; you can also request water. For the nondrinker or designated driver, there's usually cider or soft drinks for sale, and a wealth of wine knowledge to glean.