Granite soils are often associated with notable wine regions like Beaujolais, the Northern Rhône and Alsace, but “the list can go on,” says Evan Goldstein, Master Sommelier and president of Full Circle Wine Solutions. He cites Corsica, Sardinia, Spain, California, Portugal, South Africa, Australia and other areas where granite-based soils support some of the world’s most recognizable wines.
Granite forms when magma cools beneath Earth’s crust, and its composition and texture can range by location and with weathering. In the Maldonado region of Uruguay, for example, winemakers can cultivate vines on ancient granite bedrock. Eduardo Félix, the agronomist at Uruguay’s Bodega Garzón, says that “weathered granite about three billion years old that allows excellent drainage” is his team’s “secret weapon.”
This lack of water retention is a key refrain for growers working with granite soils.
Eddy Faller, coproprietor at Domaine Weinbach, cultivates Riesling in Grand Cru Schlossberg in Alsace, France, which is pure granite. He says that the “sheer poverty” of granite soils contributes to finished wines because the vines are forced to dig deep for what they need to survive.
Because water and other nutrients quickly drain in granite, yields are smaller than in other soils; Faller believes that granite is double the work and half the yield compared to limestone soil. Vines growing on granite compete with weeds and cover crops for small portions of moisture. “Vineyards have to be kept very clean, which is demanding, especially when you farm organically or biodynamically,” he says.
According to Félix, when vineyards form deep roots, better vine stability is achieved, since temperature and humidity are more constant farther from Earth’s surface. “These deep roots feed on less fertile substrates,” he says. “So, as a whole they provide better ripening of the bunches.”
Anthony Lynch, sourcing manager and director of content at Kermit Lynch Wine Merchant, says that drainage is advantageous to growers working in rainy conditions because it reduces the risk of rot and dilution. Granitic soils force vines to send their roots deeper to probe for nourishment, which makes them more resistant to extreme conditions such as heat and drought.
“There is often a marked difference between young- and old-vine cuvées,” says Lynch, “both from a viticultural standpoint as well as in the resulting wines.”
What impact does granite soil have on the wine in the glass?
“It’s often as if you can taste the vines’ proximity to the bedrock in the form of an extra degree of purity, precision and minerality,” says Lynch.
Félix believes that granite-grown wines embody “higher tension and voltage,” while Goldstein describes their “brightness and precision” thanks to elevated pH promoting high acidity. He also credits those deep-rooted vines for producing wines of layered aromas and flavors. And Faller says that Riesling produced in this environment expresses “verticality” and “long, chiseled, elegant acidity.”