A Matter of Taste - Soil: Reflections on the Basis of our Existence - page 112

Hess Collection wines, from Mount Veeder in the Napa Valley. The wine was a
Cabernet Sauvignon, the same grape associated with the finest Bordeaux wines.
For the sake of comparison, I also chose a Petit Syrah—a grape that gives a dark-
red wine—from Stags Leap, a lower-altitude Napa Valley winery. It was a Stags
Leap wine that took first prize at the legendary Paris Wine Tasting of 1976, the
first time an American wine beat top-quality French wines in a premier interna-
tional tournament. The event marked the Napa Valley's arrival as a world-leading
wine district.
Back home in Sweden, I delved deeper into the terroir concept and took part
in a tasting of Alsace wines at the Grand Hotel in Lund. Here I learnt that cal-
careous soil results in a higher acid content, which seemed logical as I knew that
many plants produce critic and oxalic acid to free up phosphorus and iron in the
soil. Alsace wines are known for their mineral notes and French winemaker Jean-
Michel Deiss believes the soil and climate are critical in determining a wine's
taste—more critical, even, than the type of grape. At the wine tasting we were
urged to filter the Alsace wine between our teeth, which the experts among us sug-
gested felt like eating stone.
Jean-Michel plants his vines closer together than other winemakers so the roots
grow deep and add quality to the wine. He believes the minerals absorbed by the
roots at depths of up to 70 m below the surface give his wines their unique taste.
He has many fans and his wines are regarded as being among Alsace's finest.
When you read about wine chemistry, you discover that vines exposed to stress
produce a whole host of substances in their leaves and fruit. UV light damages the
plant tissue, causing antioxidant pigments to form as a defence. These substances
affect the taste and are believed to offer health benefits, as they also protect human
tissue from different types of stress. But this is a controversial area and assorted
studies have found no firm link between antioxidant intake and incidence of dis-
eases like cancer and diabetes.
Vines also produce other substances that are said to affect human health.
Resveratrol, found in grape skin, has anti-fungal and anti-bacterial properties.
It has attracted considerable attention in medical research as studies indicate it
enhances longevity in simpler organisms such as yeast. There are also indications
that resveratrol makes energy use at the cellular level more efficient. It is well
known that reduced carbohydrate intake can reduce the rate at which cells age, and
resveratrol seems to have a similar effect. Laboratory tests on mice found that the
animals were able to run for longer on their treadmills and put on less fat when fed
a resveratrol-enhanced diet. There has also been speculation that resveratrol might
explain the French paradox: that the French have a very low rate of coronary heart
disease despite eating a high-fat diet.
Plants synthesise many substances to protect themselves from being eaten.
Insects gradually find ways to overcome these defences, leading the plants, in turn,
to develop new ones. This evolutionary game of tag produces complex plant bio-
chemistry that winemakers can utilise to create complexity in their wines. Grape
skins and seeds also contain tannins whose characteristic astringent taste is generated
when they interact with proteins in the palate. As a wine matures, the tannins form