Above: Samples of tufaceous (left) and calcareous (right) subsoils from Jesi. Click the image for a high-resolution version.

One of the most exciting winery visits on our recent trip to Italy was with winemakers Alessandro Fenino and Silvia Loschi at the Pievalta winery in the heart of the Castelli di Jesi.

The roughly ten-year-old winery is the first and only Demeter-certified winery in Jesi and the wines are truly stunning in their ability to deliver bright, balanced acidity with a breath-taking range of fruit and minerality.

We loved the wines and we loved Alessandro and Siliva, with whom we became fast friends (more on them later).

Above: My favorite wine was the entry-level Dominè (named after a local tavern keeper), made from grapes grown in calcareous soils. It was lighter in body and fresher than the more structured San Paolo Riserva, Tracie P’s favorite, grown partly in tufaceous soils, more tannic and unctuous and deeper in its minerality. Both wines were superb.

When you taste the wines with Alessandro and Silvia, Alessandro produces soil samples from their growing sites. I can’t think of a better way to illustrate the differences than the photo I snapped above and in the different expressions of Verdicchio that they bottle. (PLEASE FEEL FREE to grab the high-resolution version of the photo by clicking the image above and post it wherever you like.)

Not to be confused with Loire valley’s tuffeau (according to the Oxford Companion to Wine; in French, the Italian tufo is rendered as tufe or tuffe), “calcareous tufa [or tufo is] ‘a porous or vesicular carbonate of lime, generally deposited near the sources and along the courses of calcareous springs’ (Page Handbk. Geol. Terms, 1865),” according to the Oxford English Dictionary.

Calcareous, on the other hand, comes from calcaire, “French word for limestone, a rock largely made up of calcium carbonate, which may in English be described as calcareous” (Oxford Companion to Wine).

Central and southern Italy are rich in tufo. You’ll find tufo covering the Piazza del Campo of Siena when the Palio is run. Many believe that Tuscan tufo is what gives Vernaccia di San Gimignano its distinctive minerality.

Of course, there’s also the famous (however tiny) village of Tufo in Campania, where Greco di Tufo is grown in tufaceous subsoils.

And these are just a few of the examples of how limestone expresses itself through tufo in Italy.

Note how the tufo in the photo above is friable. You can see the dust it produce just by being handled, however gently. It’s one of the subsoil categories that makes Italy such a unique place to raise wine.