“You’ve got to stress the vines if you want them to produce quality fruit,” said the winemaker as he explained the need to put his vines through the tumult necessary to get maximum nutrients to the grapes.

He sounded like a father who was espousing the philosophy of “spare the rod, spoil the child.” But in fact he is correct. Great wine comes from stressed vines.

All over the northern hemisphere, vineyards are currently being harvested for the 2016 vintage. From the Napa Valley to the millions of newly planted acres in China to the fabled chateau of Bordeaux, it is the busiest time of year in the vineyards. Getting grapes from the vines and into the wineries with alacrity is the key.

While the focus is on the grapes, it is the vines that host them that are the foundation of the process. These are the “trees” that foster the production of the grapes and nurture them through the seasons until they are finally ready to give birth, if you will, to the new year’s vintage.

ROOTSTOCK

The root of the vine, no pun intended, is the rootstock that is used to create the foundation for that vine. This rootstock is the part of the vine that is planted and exists underground and forms the main line of the vine, the stalk. The actual plant material, or the budwood, that grows the grapes are generally grafted, or spliced onto the rootstock.

The selection of quality rootstock is the first and perhaps most important decision a winemaker makes. The rootstock must be drought resistant, impervious to disease and repellant to pests. This is part of the science of viticulture and if you don’t get the right stock, then your vineyard will not only not produce quality grapes, it may wither and die.

Perhaps the most famous case of rootstock causing a disaster in the wine industry occurred in France in the late 1800s, when an epidemic of phylloxera overran the vineyards of France. A tiny bug or insect, phylloxera began to feed on the roots of the vines in the great vineyards that did not have natural defenses against them. The epidemic had the potential to wipe out the grape growing industry in all of Europe if a solution was not found.

It was the realization that using rootstock from America that was resistant to the pests would provide the answer. American rootstock was shipped to Europe and cuttings from the original vines were grafted upon them, thus saving an industry and creating a firm foundation for what are generally considered the world’s greatest vineyards.

It was the grafting of the existing Vitis vinifera, the various European species of wine grapes that make wines like chardonnay and pinot noir, onto the rootstock that allowed this transformation to happen. Healthy roots supported the grapes and made for a stronger, more efficient plant.

THE LIFE OF A VINE

It generally takes two to three years or so before a newly planted vine will begin bearing enough fruit for making wines. And, early on in the life of the vine, the grapes may lack the flavor and structure that will emerge as the vines mature.

The average vine, if adequately cared for throughout each season, may provide 20 to 30 years of solid production before it begins to show signs of aging. That aging may show itself in a reduction of annual yields. But that does not mean they are of a lesser quality.

In fact, many believe that old vines produce fruit of greater concentration and character. That the stress of aging, coupled with the way in which vines adopt a relationship with the soils in which they are planted, accounts for the nuances of many great wines. Of course, the value of vine age on flavor and structure applies mostly to red wines, and grapes like zinfandel, grenache and mourvedre seem to benefit the most from aged vines.

While just about everything in the world of wine is subject to some sort of law or regulation about its origin, there is, interestingly, no actual definition, legal or otherwise, about how old the vines are that produce wines labeled “old vine.”

It has become a marketing term for many wines that are grown on vines that are, say, 30-40 years old. But there are vineyards around the world that produce wines from vines that over 100 years old.

Next time you take a sip, consider the vine. It is the foundation of your wine.

Kelly J. Hayes lives in the soon-to-be-designated appellation of Old Snowmass, Colo., with his wife, Linda, and black Lab named Vino. He can be reached at malibukj@aol.com.