Geoloog en oud-hoogleraar Alex Maltman heeft met z’n boek over wijn-mineraliteit heel wat los gemaakt. Hij bestrijdt de ‘terroiristen’ die erbij zweren dat bepaalde mineralige accenten in de wijnsmaak uit de diepere bodem komen, in plaats van uit de humuslaag daarboven. Steen geeft geen aroma af, is zijn uitgangspunt. Wij hebben aan de grote lijnen van zijn betoog al eerder aandacht besteed. Neal Hulkower van Oregon Wine Press maakt ons wat meer vertrouwd met de inzichten van deze geoloog.
'Early in this century, rather like a new comet appearing in the night sky, the phenomenon of minerality in wine arrived,” observes Alex Maltman in his literally groundbreaking book, “Vineyard, Rocks, & Soils: The Wine Lover’s Guide to Geology.” In fact, describing a wine’s smell or flavor as minerally, has been around at least since the mid-20th century — personally, in wine notes from March of 1976, referring to a 1967 Chablis Grand Cru Vaudésir from Domaine Mary Drouhin, I even used the term. So, what’s the big deal? We know Pinot scented with violets or roses, or a rosé tasting of strawberries and watermelon doesn’t mean these flowers and fruits actually flavor the wines. And yet, many people seem to think any perceived minerality originates from said minerals. Evidence supporting this belief comes from the rise in “terroirism,” the idea that the land, among other factors, influences the taste of wine. Here, for example, is the description of a 2017 Saumur-Champigny “Les Mémoires” in the March 2019 Kermit Lynch Newsletter: “And not only raspberries, but blood orange, fine tannins and incredible minerality. The stone that once built a château now fills bottles.”
‘Stones are inert’
With a series of articles starting in 2013, Maltman, a retired professor of earth sciences at Aberystwyth University in Wales who also grows grapes and makes wine, has been the leading voice in challenging the notion of “rocks” in your wine. He insists, “Stones are inert…so scientifically, it’s hard to see how they can imbue a wine with certain flavors.” With the publication of his 2018 book, Maltman offers winemakers and enthusiasts a crash course in geology with the goal of dispelling misconceptions. He begins by breaking down a vineyard into the atoms that constitute the chemical elements, of which oxygen, silicon, aluminum, iron, calcium, magnesium, potassium and sodium dominate. These elements form the geologic minerals from which rocks are made. The rocks are classified by how they were created — for example, igneous rocks from molten lava; sedimentary from the aggregation of particles; metamorphic from a variety of physical changes. Vineyards rest on bedrock, which contributes to the formation of subsoil above. The top layer is soil, a mixture of loose sediment resulting from the weathering of rocks and decaying biological material called humus; this is the arena where the main action takes place. Maltman explains, “It is the moisture and humus that make it soil, as both are required by plants.”