Clay comal: traditional surface for tortillas and toasting

What is it?

The clay comal is the traditional Mexican cooking surface: a flat disc of fired ceramic, slightly concave, that is placed over embers or direct fire to make tortillas, toast dried chillies, roast tomatoes, heat tlayudas, brown pumpkin seeds and prepare practically any food that requires dry cooking. Its porous surface, free of industrial coatings, allows tortillas to puff up without sticking and ingredients for mole, salsas and marinades to develop characteristic toasted flavours. The clay comal is especially appreciated in Oaxaca, Puebla, Michoacan and central Mexico, where traditional potters produce them using inherited techniques. Although today it coexists with iron and aluminium comales, it remains the preferred surface for hand-made tortillas and traditional mole preparations.

Origin and history

The clay comal has a documented pre-Hispanic origin: archaeological findings in Tlatilco, Tlapacoya and other sites of central Mexico show ceramic comales dated to more than 3,000 years. Fray Bernardino de Sahagun describes in the 16th century how Mexica women make tortillas on comales over three stones of the hearth (tenamaxtli), preparing tortillas that were the staple of daily food. The comal (from the Nahuatl comalli) has maintained its basic shape practically unchanged for millennia, proof of its functionality. After the conquest, it survived the arrival of European utensils and maintained its central place in indigenous and mestizo kitchens. INAH and various ethnographic studies document that potter towns such as San Bartolo Coyotepec (Oaxaca, black clay), Atzompa (Oaxaca, glazed and natural green clay), Capula (Michoacan) 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 with local clay shaped by hand or in moulds, left to dry in the sun and then fired in wood ovens at temperatures of 800 to 1000 degrees Celsius. Traditional comales measure between 30 and 60 cm in diameter, are thin (1 to 2 cm thick), slightly concave and without enamel or glaze on the cooking surface. Before first use they must be cured: they are coated with lime water or lard and exposed to low fire over several cycles to seal the porosity without obstructing its moisture-absorbing capacity. Some Oaxacan comales are also cured with cut lime. Proper use requires embers or low-intensity fire: clay does not withstand sudden changes in temperature and can crack. Its porous surface allows the masa to adhere and release properly, giving tortillas their characteristic puff. The regions have variants: the black Coyotepec Oaxacan comal is notable for its stone-polished finish; the one from Capula 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 a central place in the hearth and is considered the heart of the kitchen. Knowing how to control its temperature, knowing the exact moment of making tortillas and maintaining the cooking of the tortilla are female knowledge passed on generation after generation. In Oaxaca, traditional cooks of the 20 de Noviembre market and the Central de Abastos prepare hundreds of hand-made tortillas daily on a clay comal. The comal appears on Day of the Dead altars as an offering to maize and home cooks. Contemporary Mexican cuisine has revalued the clay comal: chefs such as Enrique Olvera, Margarita Carrillo and others incorporate it into their professional kitchens as a symbol of authenticity and the highest-quality technique for tortillas and toasted ingredients.

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 gives tortillas with traditional texture, slightly puffy 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 hand-made tortillas; iron is practical for daily cooking and withstands intensive use.

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

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

How is a new clay comal cured?

It is rinsed with water and left to dry. Then the entire surface is coated with diluted quicklime water or lard, placed over a low fire and heated gradually. Some prefer to cure it with lime juice. The process is repeated 3 to 4 times until the surface absorbs the sealant and stops staining tortillas. It is essential never to expose it to sudden changes in temperature.

Where is the clay comal from?

The clay comal is originally from Mesoamerica, with archaeological evidence of more than 3,000 years. Today the main producing centres are San Bartolo Coyotepec (black clay), Atzompa (green and red clay) in Oaxaca; Capula and Patamban in Michoacan; Metepec in the State of Mexico and various potter towns of Puebla. Each has its own technical and aesthetic traditions.