(Bloomberg) - Do you like granite? Or are you a sandy-river person? How to shop the hot, new “dirty” trends in wine.

OK, you know the names of dozens of grape varietals and wine regions and all (well, almost all) the Bordeaux crus classes. You can name with ease the best Burgundy chateaux and famous vineyards such as Napa’s To Kalon.

But you’re not done yet.

Now it’s time to bone up on the latest must-know: the “dirty” side of wine. Not the geographic region, grape, or vineyard, but what’s below the surface of the land, where vine roots sink deep into the earth that (supposedly) gives a wine its true character and quality. Soil type is the latest way to classify wines.

At the James Beard Award-winning Husk restaurants in Charleston, S.C., and in Nashville, wines on the list are organized by rock type—limestone, granite, slate, volcanic. Under limestone, you’ll see a white from Portugal; under granite you’ll find two Beaujolais reds from Fleurie.

More and more bottles are highlighting their rock roots right on the bottle as well. The first cabernets from Argentine billionaire Alejandro Bulgheroni’s brand-new estate in Napa, which are being launched next month, include two wines in a so-called Lithology line. Each features a different type of rock on the label.