Uncorked

Grapevine

Listening to some wax poetic about wine, it is easy to forget that it is just an agricultural product, like wheat or corn. There are several colleges around the country that specialize in the agricultural side of grape production, most notably UC Davis in California, where research contributes to growers’ understanding of vine, soil and climate.  Grapes are nothing more than vehicles for the seeds, providing nutrients when they hit the ground. The fruit that comes from grapes in this stage of life seems to have a slight tinny or metallic flavor that goes away with aging. There is also a difference between table grapes and wine grapes. Table grapes, such as Thompson Seedless, are all about the plump juicy character, whereas wine grapes are smaller with more concentrated flavors.

During its first three years, the vine usually does not produce grapes that are potent enough to produce any potable wine, a fact even listed in the Bible, which prohibited the use of grapes from young vines.  As the vine matures, energy is spent to grow the root stock and produce grapes. Young vines can sometimes produce up to 6 tons an acre. Over time, more energy is put into the vine and less goes to the grapes.  That’s why 100 year old Zinfandel vines will produce as little as ½ ton per acre.

Grapevines are listed by clone type. Some grapes, like Pinot Noir, are highly susceptible to mutation, therefore producing many clones. A clone differentiates in a number of ways. Some will produce different size berries per cluster; some will produce more shade in the leaf, etc. The final decision of which type to plant falls on the vineyard manager/ winemaker, who must know that a lot of leaf is needed in a hot area for protection of the berry or vice versa. For example, back in the 70s, Oregon growers started planting Chardonnay with the Wente clone that did well in California. However, with the larger leaf coverage in a cooler climate area the grapes did not get the ripeness they needed to achieve maximum exposure. Jump ahead to today, when clones are brought from the Dijon region of Burgundy where the climate more closely resembles that of Oregon.

Another farming technique is handling the foliage as it grows. This is known as trellising. As the vine shoots grow, the trellis is used to encourage the leafing to do the most good for that region and varietal. You may have seen pergolas used for grapevines; this produces a bushy affect good for visual esthetics but does nothing to protect the grapes. A more effective trellis, very commonly used, seems to be the two tier system, which allows the shoots to go upward while the grapes hang underneath protected from the elements.

Now, when you see a grapevine, look at how it is positioned, what the leaves do, and how the clusters look. It’s quite poetic in its own way.

Wines Alan is Drinking Right Now

Alamos Torrontes Argentina 2010

Guigal Rose Cotes Du Rhone 2010

St Urbans-Hof Bockstein Riesling 2010

Besame Old Vine Grenache 2008 Spain

Marco Negri Moscato Italy 2011