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74 WINES&VINES August 2018 WINEMAKING WINE EAST During our meeting, we tasted barrel samples that reflected micro- site influences on the wines. Given the diversity of the sites and the signature-blended wines, there was a satisfying consensus on many of the important aspects of soils and vines. The group identified three characteristics of a vineyard site that influenced the style, quality and success of any planting: soil water- holding capacity and permeability; slope (landscape form); and aspect (north, east, south or west). Important vineyard site aspects Water availability: Soil water-holding capacity is critical in regulating the amount of water available to the vines. A certain amount of vine hydric stress is important for making ripe, concentrated red wines. In regions with abundant rainfall, soils with lower available water are considered most desirable. Deep soils with high clay content tend to have a larger capacity to hold water, while shallow, rocky soils with less clay are droughty. In the early days of Virginia viticulture, this relationship of water availability and wine quality was not on the radar. It was only after decades of trial, error and observation that we noticed that big, lush vines produced thin, weak, anemic red wines. Conversely, small, spindly vines made the darkest, most concentrated lots. Today, the "hail Mary" approach to site selection is gradually being replaced by consulting soil scientists. Complex mosaics of quickly chang- ing soil characteristics make soil mapping tricky at best, but at least it gives a reference point to start the journey. Landscape form: While soil science is a complex endeavor, topog- raphy is pretty straightforward. A convex landscape form sheds water. The steeper the slope, the better the runoff; therefore, less water is able to enter the soil. Much of the summertime rain in Virginia is in the form of thunderstorms that can drop copious amounts of water in a short period of time. Steep slopes shed this rain, and much of it is unable to be absorbed by the soil. Certain clays can compound this runoff, ironi- cally making clay-based soils on steeper slopes more prone to excessive drought conditions. Slope aspect: The sun angle of a south-facing slope will remove moisture faster from a vineyard site. The site will also be significantly warmer. This may or may not be advantageous depending on the site, variety and desired wine style. Variety preferences Even though the sites where the three of us grow grapes are very dif- ferent, there was a lot of consensus on variety preference. Merlot: Out of all four varieties, Merlot requires a fairly steady access to water. Long dry spells in the summer can overstress Merlot and cause a photosynthetic shutdown that can continue to disadvan- tage vine performance for the remainder of the growing season. Hot, dry conditions during ripening quickly spike sugar production and overripe characteristics in Merlot. The wine then loses its charm and freshness. It's no secret that Merlot prefers water-available clay, as has been demonstrated in Pomerol and Saint-Émilion. It also prefers cooler slopes. Cabernet Sauvignon: Cabernet Sauvignon is very picky about where it grows. It grows too vigorously when it has access to water and nutri- ents. This is the problem. Virginia's first attempts to grow Cabernet Sauvignon resulted in weedy, thin and green wines. Even in the warmest climates, Cabernet Sauvignon would ripen well only in a couple of vintages a decade. In the past 15 years, however, there has been a re- newed focus on soils that are appropriate to Cabernet Sauvignon, and this has made a huge difference. If there is enough hydric stress during Young Cabernet Sauvignon vines on the southern slopes of RdV, where gradients can reach as much as 30%. PHOTO COURTESY OF RDV VINEYARDS