Friday, April 6, 2007

Old Vine Wines

You’ll sometimes see on a label the term “old vines,” or vieilles vignes as the French has it. But what’s an “old vine” wine?

A wine made from grapes grown on an old vine, of course. But what does that signify?

First some background and history. Today establishing a grape vine is a two-part process -- selecting a root stock and grafting a particular grape variety onto it -- and this is because in the mid 19th century virtually all the vineyards of Europe were wiped out when they were attacked by a root-eating aphid called phylloxera. The results were devastating and came close to ending forever European wine making. Phylloxera was introduced into Europe through the importation of infected plants from the United States, mostly by well-to-do amateur horticulturists for their gardens and greenhouses.

At first no one understood what was behind the devastation, but once they identified the root system as the root of the problem, they began searching for ways to solve it. What they discovered was that grape varieties native to the United States, species such as vitis labrusca (which produces the Concord grape, for example) and vitis rotundifolia (the Scuppernong being the best known example) had over the centuries built up a resistence to phylloxera. So they brought American root stock to Europe and grafted European varieties of vitis vinifera (Cabernet, Pinot, Chardonnay, etc.) onto it. This practice continues today, although now there are designer root stocks that are not only phylloxera-resistant, but also offer other selected advantages, such as doing well in an arid environment, in dense soils, or more northern latitudes. The selection of a root stock is a very major consideration in the planning of a vineyard.

Once the root stock is selected and a variety of vitis vinifera grafted on to it, it takes from three to six years before a vine can produce worthy fruit. In the very early years, any grapes produced are discarded. In the next few years, before full maturation, the grapes may be used for table wines or distilled into cheap brandy. During this development process, the vine is slowly trained on to a trellis and is shaped in such a way as to best catch the sun’s rays while at the same time shading the developing grapes from overexposure. “Canopy management” is very important because it is through the magic of photosynthesis that sunlight, water, and soil are slowly transformed into sugar, acid, and the several hundred trace elements found in wine.

Once a vine is mature it is never allowed to produce all the grapes it can, at least not if the goal is to make superior wine. Rather, it is subjected yearly to at least two prunings, one in the early Spring, when a portion of the freshly-set green fruit is removed, and later when the berries are close to being mature. In many cases more than half of the potential grapes will be removed before they can develop. The purpose of this is to increase the quality of the remaining grapes, i.e., their sugar content, by directing the available nutrients to fewer bunches.

The decision as to when and how severely to prune is another of those major decisions a winemaker must make. He or she is forever balancing quantity against quality. If too many grapes are allowed to mature, or if too many vines are crowded into the available space, then the wine will be thin and watery. If too many grapes are cut away, or vine density is too sparse, there is a chance not enough wine can be made to recover costs.

This combination of plant density and pruning determines “crop yield,” expressed as so many tons-per-acre. You will sometimes see this figure quoted on a back label. What a winemaker is trying to tell you is “I was not overly greedy. I’ve chosen to produce a smaller amount of a better wine rather than a larger amount of an inferior one.”

Vines can live and produce for fifty to seventy-five years, in some cases even longer. In general, however, they top out at about twenty years of age and their productive capability begins to decline. As they get older they self-regulate, so to speak, by limiting the amount of grapes they produce. Their root systems, however, have penetrated deep into the ground and spread out extensively in all directions. This combination of fewer grapes and a massive root system that can still efficiently extract nutrients from the soil is what makes grapes from old vines special. Wines made from old vine grapes tend to have a more concentrated flavor and a more complex character. Thus, as is true with a lot of older things (including we humans), old-vine wine can be more interesting.

Unfortunately there is no agreed upon age at which a vine becomes an "old vine," nor is there any guarantee an old vine will produce particularly good grapes, or that a particular winemaker will produce an exceptional or even good wine from them. But the potential is definitely there, and this makes it worthwhile to take note of wines said to be made from old vines.

So, if you encounter the term, look on the back label to see if the age of the vines is given, along with their yield-per-acre. While the actual affects of vine age and yield on a given wine is impossible to tell in advance, if a winemaker is willing to give specifics this is an indication of his or her honesty and seriousness. Because there is no established standard as to what constitutes an “old vine,” there’s room for misappropriation, which is to say unscrupulous winemakers can put it on their labels purely as a marketing ploy.