Clay comal: what it is, its uses and tradition

What is it?

The clay comal is Mexico's traditional cooking surface: a flat disc of fired ceramic, slightly concave, placed over embers or a direct flame to cook tortillas, toast dried chillies, roast tomatoes, warm tlayudas, brown pepitas and prepare virtually any food that calls for dry-heat cooking. Its porous surface, free of industrial coatings, lets tortillas puff up without sticking and allows the ingredients for mole, salsas and adobos to develop their characteristic toasted flavours. The clay comal is especially prized in Oaxaca, Puebla, Michoacán and central Mexico, where traditional potters make it using inherited techniques. Although it now coexists with iron and aluminium comales, it remains the favourite for handmade tortillas and traditional mole preparations.

Origin and history

The clay comal has documented pre-Hispanic origins: archaeological finds at Tlatilco, Tlapacoya and other sites in central Mexico include ceramic comales dated to more than 3,000 years ago. In the sixteenth century, Fray Bernardino de Sahagún described how Mexica women cooked tortillas on comales set over the three hearthstones (tenamaxtli), preparing the tortillas that were the staple of daily life. The comal (from the Nahuatl comalli) has kept its basic form practically unchanged for millennia, proof of how well it works. After the conquest, it survived the arrival of European utensils and held its central place in indigenous and mestizo kitchens. The INAH and various ethnographic studies document that pottery villages such as San Bartolo Coyotepec (Oaxaca, black clay), Atzompa (Oaxaca, green-glazed and natural clay), Capula (Michoacán) and Metepec (State of Mexico) produce traditional comales that are exported throughout Mexico and abroad as heritage utensils.

Characteristic ingredients

The clay comal is made from local clay shaped by hand or in a mould, left to dry in the sun and then fired in wood-burning kilns at temperatures of 800-1000°C. Traditional comales measure between 30 and 60 cm in diameter, are thin (1-2 cm thick), slightly concave, and carry no enamel or glaze on the cooking surface. Before first use they must be seasoned: they are coated with limewater or with lard and exposed to a low flame over several cycles to seal the porosity without blocking the clay's ability to absorb moisture. Some Oaxacan comales are also seasoned with a cut lime. Proper use calls for embers or a low-intensity flame: clay does not tolerate sudden temperature changes and can crack. Its porous surface lets the masa grip and release at just the right moment, giving tortillas their characteristic puff. Regions have their own variants: the black Oaxacan comal from Coyotepec is notable for its stone-burnished finish, while Capula's has reddish tones.

Cultural significance

The clay comal is a symbol of traditional Mexican cuisine, recognised by UNESCO as Intangible Cultural Heritage of Humanity in 2010. In indigenous and rural communities, the comal occupies the central place on the hearth and is considered the heart of the kitchen. Knowing how to control its temperature, judging the exact moment to turn the tortilla and keeping the cooking steady are forms of women's knowledge passed down from generation to generation. In Oaxaca, the traditional cooks of the 20 de Noviembre market and the Centrales de Abasto make hundreds of tortillas by hand every day on clay comales. The comal appears on Day of the Dead altars as an offering to maize and to the cooks of the household. Contemporary Mexican cuisine has rediscovered the clay comal: chefs such as Enrique Olvera, Margarita Carrillo and others have brought it into their professional kitchens as a symbol of authenticity and as the finest technique for tortillas and toasting.

Frequently asked questions

What is the difference between a clay comal and an iron comal?

The clay comal is porous, absorbs moisture from the masa and produces tortillas with a traditional texture, slightly puffed and with earthy notes. The iron comal retains more heat, is indestructible and allows cooking at higher temperatures. Clay has a distinctive flavour and is preferred for handmade tortillas; iron is practical for everyday cooking and stands up to intensive use.

What does a tortilla cooked on a clay comal taste like?

It has a characteristic earthy flavour, a light smokiness if heated over wood, and more intense toasted-maize aromas than on an iron comal. The texture is fluffy in the centre and crisp at the edges. Chillies toasted on clay release more essential oils and develop a complexity impossible to achieve on industrial surfaces.

How do you season a new clay comal?

Rinse it with water and leave it to dry. Then coat the entire surface with diluted limewater or with lard, set it over a low flame and heat it gradually. Some prefer to season it with lime juice. The process is repeated 3-4 times until the surface absorbs the sealant and stops marking the tortillas. It is essential never to expose it to sudden changes in temperature.

Where does the clay comal come from?

The clay comal originated in Mesoamerica, with archaeological evidence going back more than 3,000 years. Today the main production centres are San Bartolo Coyotepec (black clay) and Atzompa (green and red clay) in Oaxaca; Capula and Patamban in Michoacán; Metepec in the State of Mexico; and various pottery villages in Puebla. Each has its own technical and aesthetic traditions.