There are more than 5,000 varieties of wine grapes (Vitis vinifera).
Only about 230 are used to make quality wine. Only about 80 account for the bulk of production.
Even so, 80 different grapes—a dizzying assortment. What’s a consumer to do?
The answer came when winemakers began identifying wine by the predominant grape. UC Davis, the premier wine university, refined and championed this practice beginning in the 1950s, and such labeling gets credit for the wine boom that began in the 1970s and continues today.
The practice is called “varietal labeling,” and it has strict rules varying from country to country.
In the United States, a varietal must contain at least 75 percent of the grape named on the label. In Australia, it must be 80 percent. French frown, although they are coming around.
Common varietals include Cabernet Sauvignon, Merlot, Zinfandel, Pinot Noir, Syrah/Shiraz, Chardonnay, Sauvignon Blanc, and Riesling.
When the label has two grape names, such as Cabernet Sauvignon-Merlot, it is a blend and not a varietal.
Varietal labeling gives the average wine drinker a clue about what to expect. Cabernet Sauvignon has plum, currant, black cherry flavors. Zinfandel pepper and wild berry flavors. Sauvignon Blanc herbal and light.
Other varietals are emerging: Malbec and Sangiovese from Argentina and Cabernet Franc in the New World and Australia. These grapes have been classic parts of wine blends for centuries; now they are making names for themselves all alone.
• Alexander Valley Merlot. Cherry, blackberry, toasty oak, fruit-forward. $19
• Summer’s Cabernet Sauvignon. Iconic Napa Cab. $43
• Bouchaine Estate Chardonnay. Citrus busts amid cream of malolactic fermentation deliver elegance. $26