Wine Grapes and Grape-y Wines
© Donald A. Dibbern, Jr.
As I was biting into a juicy, aromatic Muscat grape at a recent Wine & Spirit Education Trust tasting, it occurred to me that wine lovers don't often have the opportunity to taste the grapes tht go into our favorite wines. When was the last time you tasted a ripe Chardonnay grape, or a Pinot Noir grape?
Perhaps surprisingly, most wine-grape varieties aren't normally used as table grapes, and vice-versa. This is primarily because wine grapes and table grapes are selected on the basis of different characteristics.
The ideal table grape should be easy to eat out of hand without making a mess, so fruit growers choose table varieties with thin skins and either no apparent seeds or only tiny, edible seeds. In grapes destined for wine, however, much of the flavor and tannins and virtually all of the color comes from the skin. (Many wine enthusiasts don't realize that, with rare exceptions, the juice of black, purple and red grapes is "white" or clear.) So, for wine, thick-skinned grapes are desirable because they produce robust, flavorful, tannic and long-lived wines. Seeds are left behind in the "pomace" of pressed grape skins, stems and seeds after the grapes have been pressed. This isn't much of a problem, although wine makers know that the grapes must be pressed gently, not roughly, as breaking the seeds will release bitter oils into the wine, a bad thing.
The ratio of sweet, juicy pulp to inedible matter in the grape is economically significant as well. The Asian Red Globe variety, for instance, is popular as a table grape because it is large. A small, dense berry may seem like more trouble than it is worth to eat, but it's ideal for making rich complex wines, as the juice macerates the skins, extracting and soaking in the flavors.
Indeed, if the grapes are too large, winemakers sometimes must even "bleed" fermentation vats of some of their juice - a process called saignée - to increase the ratio of skin to juice. This can happen, for example, if there are heavy rains at harvest and the berries are swollen and waterlogged.
A few grape varieties, notably the Muscat I mentioned - can do quite nicely as either a table grape or a wine grape. In this case, the decision may be simply economic, depending on the local market and prices offered for table grapes, raisins or wine grapes.
So, what do wine grapes taste like? This brings to mind a startlingly brazen scene from the movie Mondovino, in which the filmmaker's camera caught a tourist apparently casually snacking on grapes right off the vine at Domaine de la Romanee-Conti without permission.
Not surprisingly, perhaps, wine grapes rarely taste exactly like the wines they make, since you don't generally eat the skins of these varieties. While volunteering at local wineries here in Oregon, I have had the opportunity to taste ripe Chardonnay and Pinot Noir grapes at harvest and crush. I found both quite delicious, intensely sweet and much juicier than the usual Thompson Seedless (Sultana) table grapes. They did not, however, necessarily show the characteristic green-apple flavors of Chardonnay wine or the red fruit flavors - cherries, raspberries, plums - commonplace in Pinot Noir wine.
Muscat does indeed taste "grapey," and Concord, the Vitis labrusca native grape variety that's widely grown in the Eastern U.S. and Canada, has a pronounced candied grape-jelly flavor in both the grape and the wine. The term "foxy" is often used for labrusca variety wines, confusingly not referring to an animal scent, nor used as a slang term of approval, but to this characteristic aroma and flavor of grape juice or jelly. Apparently this term comes from the common name for these wild American vines as the "fox grape," which itself possibly derives from Aesop's famous fable of the Fox and the Grapes. And we won't even discuss the fact that Vitis vulpina is known as the "frost grape," instead of the fox grape, despite vulpina being Latin for vixen.
Why do ripe wine grapes taste so sweet? Simply put, sugar is a virtue in wine grapes, because it takes sugar to produce alcohol. Wine brapes are usually picked around "24 Brix" at harvest, to use a technical term, which translates to sugar content of about 260 grams per liter (roughly 24 percent). If the wine is fermented to dryness - converting all the sugar to alcohol so no sweetness remains in the finished wine - this result in a final alcohol level of 13 to 14 percent. Before it ferments, though, this juice is seriously sweet. In comparison, Welch's 100 percent Concord grape juice contains 40 grams of sugar per 8-ounce (240 ml) serving. This translates to about 165 grams per liter, only about half as sweet as the juice of unfermented wine grapes at harvest.
Wine, of course, can be made from any grape (and from most fruit juices) simply by the action of yeast fermenting the sugar to alcohol. Even Thompson Seedless (Sultana) grapes are used to make wine, primarily as a neutral and relatively inexpensive "filler" for inexpensive jug wines.
Some wines are even made from dried grapes - essentially raisins. Wines of this type, including the Italian Amarone, Recioto and Vin Santo and the French vins de paille. Wines of this type often carry intense, "cooked" raisin flavors into the resulting wine. Indeed, at least in the novelty realm, things come full circle with fine wine grapes like Chardonnay and Pinot Noir occasionally turning up in fancy, upscale and expensive jams and jellies!
I hope this topic has given you food for thought, the next time you sit down to a glass of your favorite grape beverage.
© copyright 2007 by Donald A. Dibbern, Jr., all rights reserved
To contact Donald A. Dibbern Jr., write him at firstname.lastname@example.org