Vineyard Soil Types
Minerality is a conversational subject in the wine world. There is not yet any scientific evidence that supports the idea of the flavor of the soil coming through in the wine. That is not to say, however, that soil does not affect the aromas and flavors of wine. Although perhaps not in the way you might think. The vineyard soil type works with the vine and the climate to provide water drainage, exchange nutrients, retain heat or cool the vines, and alter the acidity in the grapes. This is a complex subject, but most of the soil types in the world fall under a broad category
Alkaline soil composed of ancient marine life that has been compressed over millions of years, with high amounts of calcium carbonate. Limestone is famous for quality winemaking in that it offers good drainage in wet weather but retains water in dry weather. It can reflects sunlight to promote photosynthesis and has a high pH (which means increased nutrient exchange between the soil and the vine.
Properties: Aromatic, elegant, high acid wines.
Classic regions: Champagne (chalky limestone), Chablis, St. Emilion
Loam soils are soft and fertile, combining several types of rock, including clay, sand, and silt. This vineyard soil type is not associated with quality winemaking. The vines do not struggle as much, so there is more vigor and less concentration to the fruit. Good wine is possible with vineyard management.
Properties: Often light in color and body, unless carefully managed or combined with another soil type.
Classic regions: Barossa Valley
Sandy soils are made of large particles, so they offer good drainage. This can mean that nutrients are deprived, but it also prevents the root louse phylloxera from attacking.
Properties: Fresh, aromatic wines, often lighter in texture.
Classic regions: Chianti Classico & Barolo but not the only soil in either regions!)
This is another fertile soil, composed of materials left behind by rivers. There is a fair amount of organic material in the soils. This tends to be a mix of gravel, silt, and sand. Like loam, vineyard management must be practiced. Properties: Lower acid, less aroma. Classic regions: Napa Valley
Made up of dense sedimentary rock, clay soils are heavy. This vineyard soil type retains water well, although drainage can be poor. In warmer climates, clay soils’ moisture capacity is especially beneficial to vines. When there’s low rainfall, the water retained in the soil extends the amount of time water is available to the vine.
Properties: Dark color with firm tannin and high extraction.
Classic regions: Pomerol, Rioja Baja
Silt soils have a fine texture. It has good water retention due to the small particles of the soil, but this can also result in waterlogging, which can lead to vineyard disease. Loess is a wind-blown type of silt with high portions of silica
Properties: These wines tend to be rounder and smoother, as the wines tend to be lower in acidity.
Classic regions: Columbia Valley, Washington. Lower Austria
Made of lava that has been cooled and turned into rock. These soils are high in iron, offer good drainage as well as heat and water retention.
Properties: Complex, ashy wines.
Classic regions: Santorini, Sicily