Once planted, it takes about five to six years to produce wine grapes
Published in the April 30 – May 13, 2014 issue of Morgan Hill Life
By Cindy Adams
Cindy Adams
We are lucky to live in the Valley of Heart’s Delight where we can enjoy beautiful orchards, fields and vineyards. Most of our local wineries are surrounded by their own vineyards (called their “estate”). I often get questions about why the vines look the way they do at certain times of the year, and what’s happening to them. In order to understand the life of a vineyard, let’s start with the birth of the vine.
It might surprise you to learn that you just don’t go to a nursery, buy a grape vine, and plant it in the ground. In the mid-1800s a disease called phylloxera attacked most of the vineyards in Europe. This disease was brought over on some vines and is indigenous to North America, so our native grape varieties had developed resistance.
An American horticulturist suggested grafting European vines on to American root stock. So, if you are planting vines, you would need to choose the proper root stock for your particular soil, and then decide on the varietal (type of grape). After you do that, a clone is grafted onto your root stock and, when it is successfully growing, then you can plant it.
Once you do plant your vineyard, it will take about five to six years to produce good wine grapes and your vines will have a life expectancy of 20 to 30 years, depending on the varietal. Some varietals like Zinfandel can produce good wine grapes for much longer than that — some Zin vines producing fruit up to 100 years.
From December through February, the vineyards are “sleeping.” This dormancy phase takes place from the first of winter until the early spring. Sometime in January or February, though, the sleeping vines are pruned and trellised. This is done to provide the best harvest. Dead shoots are pruned off so they won’t draw nutrients away from the vine. Trellising is done to provide the best shade cover and air circulation for the next vintage of grapes.
In our local vineyards, the 2014 vintage is being born about now. In the early spring, you will notice the brown vines are starting to turn a little green. If you get up close to one, you will notice that the little buds are starting to break open. This is called, appropriately, “bud break” and it signifies the emergence of the shoots and foliage that will become the leaves, stems and fruit.
As the days lengthen and the weather warms up, these baby shoots will grow and you’ll begin to see groups of tiny berries on the vine. With luck and good management, these berries will become wine.
In the late spring and early summer, the vines go through what is called “fruit set.” This is when the grapes “set” on the vine, grow and develop. As much as we need rain right now, any rain after the vines begin fruit set could be detrimental to the grapes because, if they get wet and stay wet for any period of time, they could develop mold and wouldn’t be able to be used for wine. Some mold is good on certain grapes (such as Botrytis or “Noble Rot”) and those grapes are used to make dessert wine. But for most wines, the winemaker can’t use grapes with mold.
For most of the growing season as the grapes are maturing, they keep their original bright green color. This perplexes a lot of people who normally think of wine grapes in various shades of purple. As summer progresses and the sun warms the grapes, they go through a process called “verasion.” This is when most of the grapes change color from that bright green to the light purple to dark violet colors that most people expect.
In late summer, the winemaker will go into the vineyards and test the grapes for sugar content. The measurement of sugar in the grapes is called the Brix and grapes are generally harvested when they reach 19 to 25 Brix.
The last step in the life cycle of the vineyard is the harvest. This can take place from late August to mid-September and continue through November depending on how ripe the grapes have grown. At that point, the grapes are well on their way to becoming the wine you’ll enjoy with your family and friends at dinner and special occasions.
Cindy Adams, CS, CSW, is the director of retail operations at Guglielmo Winery.
