We asked RTD Vines & Wines columnist Jack Berninger to harvest some grape information for thirsty (or simply curious) Virginians. Here, he shares some basics of nature and nurture.
Winemakers get credit for flavor and aroma, but look past the winery or lab for a moment. A great wine is largely created outside, where conditions and skill come together in the vineyards.
Say what? An all-encompassing French term – terroir – defines the overall environment (soil, climate, topography) in which grapes are grown. Talk to a vineyard manager or winemaker, and the word will surface.
The good earth: Well-drained soils are key to producing quality wine, and they vary greatly in Virginia. In the east, soil is generally sandy and loamy. (Loam is a mix of sand, clay and silt.) In the Monticello area, there's granite-based clay. In the Blue Ridge, soil is loamy and gravelly. In the north, there's granite and sandstone. And in the Shenandoah and Appalachia areas, soil can be rocky.
A tough forecast: Warm, dry summers and mild winters are a vineyard manager’s dream, but Virginia’s fickle climate can challenge grape growers. An early frost can destroy tender new buds. Humidity can lead to rot and disease. Too much rain just before or during harvest can lead to grape-swell and a diluted juice. Harsh winters can destroy vines.
Uneven ground: Most vineyards are planted on hills or mountainsides – usually facing south or southwest, to allow more sunlight to reach the leaves and grapes. Vines are planted up the inclines to emphasize good drainage and to avoid frost in a valley.
Good stress: Poor soil, not enough water, a lack of sun – these sound like precursors to a bad crop, but that's not necessarily so. Vines tend to do better when they are lightly to moderately stressed: They focus their energy on surviving. For example, if water is scarce or quick to drain, the vine roots grow deeper and stronger in search of water.
Vine management: Pruning, trellising and spacing are key to the growth of vines and grapes:
* Pruning in the dormant days of winter shapes the vine to produce in the spring. (Summer pruning, such as cutting low-hanging or fragile fruit, can help the vine put more energy into its remaining clusters.)
* Trellising gets the vine off the ground and allows sun and air to caress the leaves, giving grapes a better chance to mature with good flavors.
* Theories abound about spacing between vines and between rows. If too close, vines compete with one another. If too far, fewer vines will produce fewer grapes, which affects economics.