Zvi Bern and Debby Wagger of Los Angeles tasting wine at one of the WineStations at Copia.

Wine critics are forever rambling on about malolactic fermentation, carbonic maceration, French vs. American oak, "corked" wines and the like, but how many wine enthusiasts actually can relate to the concepts through aware personal experience?

Only a few, I suspect. Now, however, Copia: The American Center for Wine, Food & The Arts in Napa has installed a bank of machines to help enlighten visitors to wine jargon.

Each "WineStation" holds four bottles of wine grouped to make a point. One set, for example, shows how different types of oak affect chardonnay. One of the four wines hasn't been exposed to any oak at all. One has been doctored with oak chips. One has been aged in American oak barrels. And the fourth has been aged in French oak barrels.

Here's the drill: Visitors buy a debit card, insert it into the WineStation and then select a small taste, half glass or full glass of whatever wine they want to sample. After a taste of the unoaked chardonnay, for example, they can taste the chardonnay that has been treated with oak chips, then move on to the wine aged in American oak.

Another WineStation features wines chosen to help visitors identify common faults in wine, such as volatile acidity, brettanomyces and contamination by 2,4,6-Trichloroanisole, the compound that indicates a wine is "corked," or smelling like wet cardboard. You may want to only sniff these wines, not taste them.

After a stop at Copia and a visit to the dispensers, visitors will be well armed to continue their tasting trek up valley, or to maybe just read a wine column. Copia, 500 First St., Napa, is open 10 a.m.-5 p.m. daily except Tuesdays. Admission is $5.