Greek volcanic terroirs are found mostly in the vineyards of Santorini, where vines are planted on a white layer consisting of lava, Therean ash and pumice, whose depth varies from 30 to 50 meters and has been deposited there by the successive eruptions of the volcano through time immemorial. As a result, the soil of the island’s vine growing areas is deep and sandy with a complete absence of organic matter and thus not susceptible to phylloxera.
This “mother” lode enriches the soil with calcium, magnesium, ferrous iron and silicium but is poor in potassium which may serve to explain the especially high acidity the grapes have at their ripening peak. The soil’s low fertility and moisture capacity is offset by the capacity vine roots have to penetrate deep into the ground due to the soil’s loose composition. Indeed, since every 80 years or so the basket-shaped vines (kouloures) are pruned back down to the ground so that the “basket” may be revitalized, the true age and actual depth of the roots of Santorini vines remain unknown.