If you've never "tasted" wine before, keep one thing in mind: Taste is actually the last sense you use to appreciate wine. First, look at its color. Newer vintages tend to have a deeper, purple hue; a pinot noir will be paler than a cabernet sauvignon. If it's a sparkling wine, watch it effervesce—the smaller the bubbles, the higher the quality of the wine. If you're tasting a still wine, swirl the glass. This pushes the liquid up the sides of the glass, increasing surface area and thus evaporation, maximizing the aromas, also known as the nose, or bouquet. You'll find that it's easier to get a graceful swirl when you leave the glass on the counter and make circles with your hand resting on the base. (By the second night of the trip, you'll find yourself swirling your water glass at dinner.) Dip your nose into the glass and think about what you're smelling. Cherries? Blackberries? Leather? Cigar smoke? Then tip a bit of wine into your mouth and let it glide over your tongue, hitting all your taste buds. Some people suck in a bit of air at this point, to further aerate the wine. Finally, either swallow the wine or spit it into the available bucket. Don't be afraid to ask whatever questions come to mind, no matter how silly they seem. After all, many wineries call their tasting staff "wine educators."

To fortify yourself for the afternoon's two tastings, retrace your route back to Highway 121 and turn left into the Carneros Inn's second entrance for a quick lunch at its Boon Fly Café (707-299-4870; entrées, $11–$18), a barn-red roadhouse serving elegant sandwiches. Pay your check by 1:45 and head to your two o'clock appointment at Bouchaine Winery (1075 Buchli Station Rd.; 707-252-9065; bouchaine.com), a classic Carneros chardonnay and pinot maker in the part of the valley known as the flatlands, where rolling fields of vines stretch in every direction. In contrast to the rather formal tone at Artesa, where a recording of chanting monks plays constantly in the barrel room, Bouchaine doesn't take itself too seriously. Here the background music for your tasting is a local radio station, and the staff might describe a wine as "growing fuzz on your toenails." Like many wineries, Bouchaine will waive your tasting fee if you make a purchase.

Your 3:30 appointment is just a few minutes away through a patchwork of grape fields at Ceja Vineyards (1248 First St.; 707-255-3954; cejavineyards.com), voted the best new winery in 2002 by the San Francisco Wine Appreciation Guild. Chances are you'll meet Ariel Ceja (pronounced SAY-ha) behind the tasting bar in the family's home; Ceja is the son and nephew of Mexican immigrants who started out working in the fields here and now own 113 acres of grapes. They've just opened a tasting salon in downtown Napa, and are working through the county's formidable red tape to build their own winery (they currently rent space elsewhere to process their grapes). The family's varietals run the gamut: sauvignon blanc, chardonnay, pinot noir, syrah, merlot, cabernet sauvignon, and two blends called vinos de casa. By late after noon, chances are there will be a small crowd at Ceja's bar and salsa music playing.