Five Things I Learned from Steve Matthiasson’s Talk “Viticulture: The Farmer’s Role in Terroir"
Steve Matthiasson and Jill Klein Matthiasson are effecting change in the California wine world through the integrity and thoughtfulness of their farming and the balance and beauty of their wines. The couple operates seven vineyards in Sonoma and Napa using sustainable farming practices. Their wines are food friendly, lower in alcohol, and well balanced. Steve approaches winemaking from the ground up and strives to reflect each varietal's true character and terroir.
Matthiasson believes that proper treatment of the grapes and the land are more important than the perfect terroir. “It’s fatalistic to pre-evaluate terroir,” he cautioned in his recent lecture “Viticulture: The Farmer’s Role in Terroir”. The viticulturist has a multitude of resources for affecting the quality of the grapes; vine balance, crop load, soil management, watering, and root hormones are just a few of the areas he explored. Below are five surprising examples of how the farmer’s technique affects grapes and ipso facto wine.
1. “Jamminess” is the result of grapes that are “cooked” on the vine! Intense, fruity, “jammy” flavors in wine are produced when grapes are over-exposed to the sun. Many California grape growers emulated the crop orientation of French regions they admired such as Burgundy and Bordeaux – regions with climates far cooler and less sunny than Napa and Sonoma - where crop rows are positioned facing west to receive the maximum amount of hot afternoon sun. In sunny California, the gentle, morning sun provides an appropriate amount of light for grapes to grow. As a result, fruit on vines oriented towards the west have a propensity to over-ripen on the vine, thus reducing the varietal’s natural aromatics and enhancing the fruity qualities of the grape.
2. Grassy and tropical fruit flavors in Sauvignon blanc are not a reflection of the varietal’s true characteristics. “Sometimes bad winemaking practices affect our expectations of a varietal,” Matthiasson pointed out. He used the example of Sauvignon blanc. This extremely adaptable and vigorous grape is often planted on California’s least desirable terroir. “There is a hierarchy of terroir,” says Matthiasson. Cabernet sauvignon, California’s signature varietal, receives the most prized lots, followed by Merlot. Because Sauvignon blanc grows so easily, it is planted in areas deemed “undesirable” and given less attention. Vines often become too vigorous – lanky, long and overgrown – and over-produce fruit. These grapes lack phenol – the element that gives wine density and structure - and creates gassy “green” characteristics in wines. If vines have low vigor–vines that are stocky and spread thin - they produce fewer grapes with higher sugars generating the tropical fruit flavors we often associate with Sauvignon blanc. Both of these issues are the result of poor pruning and influence the quality and character of the grapes and eventually the wine.
3. The quality of a vintage is not determined during the harvest. There is a common misconception that the weather during the harvest determines the quality of the vintage. Contrary to popular belief, the flavor is already there by harvest time. By that point, the weather only has an impact on the grapes if it is severe enough to cause damage to them. The weather in spring and summer defines the vintage. Much of this has to do with how spring and summer rainfall determines the production of seeds. During a dry season, the plant experiences high levels of stress, provoking grapes to produce seeds - the fruit's natural defense. Seeds are where the fruit stores tannins – the element that causes a wine to be dry and bitter. The bitter taste deters wildlife from consuming the grape before the seeds are ready. Hence, a dry spring translates to a more tannic wine, whereas a wet spring translates to less tannic wine. If the plant is “happy” it does not need to produce seeds at all!
4. Vine roots have a micro-biome similar to the gut biome of a human. Matthiasson likens the human gut micro biome to the vine’s root micro biome a.k.a. the root rizosphere or put more simply, what lives on the roots of vines. Roots and vines have a symbiotic relationship; the roots send signals to the fruit based on what is happening underground. Like humans, plants build up immunity when they are exposed to disease. A healthy gut or root micro biome helps prevent disease. Matthiasson has observed in his years of fieldwork that when farmers use herbicides grapes develop higher levels of sugars before they develop flavor; grapes growing on healthier soils with cover crops tend to develop more flavors. Though not proven by science, he posits that this phenomenon is the result of roots not working as hard to bring healthy bacteria and nutrients to the plant for disease prevention.
5. Depriving vines of water and using competitive crop cover protects the plants from heat blasts. The best grapes are produced from vines that go through periods of stress and dryness followed by heavy rain and irrigation. Matthiasson waters his vines infrequently but for long periods of time to ensure that the plants have a reserve of water underground should a dry spell occur. Cover crops planted between rows of vines compete with vine roots forcing them to grow downward. This ensures the roots draw water from deep below the surface and thereby are protected from heat blasts.
Written by Laura Robards.