Hot Rocks

Stones are a key element of the horno, the firepit oven in which we roast our maguey piñas for Eléctrico Mezcal. Piled on top of the slow-burning oak, they must become white hot before Maestro Cirino adds the piñas. He covers them with sacking and earth and then leaves them to cook for three days.

Cooking with hot stones is used worldwide, an ancient method of transferring heat to food flamelessly, from the days before cast iron hobs and steel griddles. However, one part of Oaxaca is famous for using a white-hot stone to cook soup.

In San Felipe Usila, way up to the north of Eléctrico Mezcal palenque, the tradition is that the women relax and bathe in the river while the men make stone soup or Caldo de Piedra. A small fire is lit to heat a large, smooth pebble from the stream. A suitable water-carved depression in the riverbank rocks is chosen and cleaned out. Chiles, tomatoes, herbs, seasoning, and freshly caught river fish are placed in it. Cold, clear river water is poured on top, and then, gripped in a cleft, green stick, the white-hot stone is dropped in.

The water boils almost instantly, and within two minutes, the fish is cooked and the soup ready for the waiting women to savor.

You don’t have to travel all the way to San Felipe Usila to taste this delicious addition to the Oaxacan table. There is even a restaurant named Caldo de Piedra just outside Oaxaca City on the 190 highway that takes you to the Eléctrico Mezcal distillery. It is renowned for its stone soup, which, as you might expect, is served in large gourd bowls, bubbling furiously with a hot, black rock in it.