Comal toasting: what it is and how it's done

What is it?

Toasting on a comal is the ancestral Mexican technique of heating dried chillies, seeds, spices, nuts, tortillas and other ingredients on a comal —a flat clay or iron disc— at a medium-high temperature without fat, until they release aromas, lightly brown and develop deep flavours. The comal (from the Nahuatl 'comalli') is the quintessential pre-Hispanic utensil of Mexican cooking, the base for making tortillas, roasting, toasting and keeping food warm. The toasting technique is applied especially to prepare mole pastes, salsas, adobos, atoles and all kinds of preparations where the aim is to concentrate and refine flavours. Unlike tatemado (where the aim is partial charring), toasting is controlled: the aim is to brown without burning, since burning seeds and spices produces irreversible bitterness. It is a key technique in the traditional cuisines of central, southern and south-eastern Mexico.

Origin and history

The comal is a fundamental pre-Hispanic utensil in Mesoamerican cooking, dating back more than 3,500 years. The oldest known comales are round pieces of fired clay found at Olmec, Maya and Mexica sites, described in the Florentine Codex of Father Bernardino de Sahagún (sixteenth century). They were the centre of the domestic hearth along with the three tenamastles (stones that held it over the fire), where cooking went on all day. The toasting technique developed alongside the comal: toasting dried chillies to soften their skin, toasting pumpkin seeds (pepita), sesame, peanuts and chocolate to release aromatic oils, toasting whole spices to activate volatile compounds. According to Larousse Cocina, traditional toasting uses clay comales from Atzompa, Oaxaca, or Comonfort, Guanajuato, which provide a subtle mineral flavour. Wrought-iron comales became popular in the twentieth century. Today they coexist with industrial griddles in restaurants and with domestic pans in urban kitchens. México Desconocido documents the comal as the 'heart of Mexican cooking', present in indigenous, rural and urban kitchens, from humble homes to Michelin-starred restaurants.

Characteristic ingredients

Toasting on a comal has specific variants depending on the ingredient. For whole dried chillies (ancho, mulato, pasilla, guajillo, chipotle): they are deveined and placed on a dry comal over a medium heat, turning constantly for 30-60 seconds until they crackle slightly and release aroma; they should not darken too much (burn) because they turn bitter. They are then hydrated in hot water for 15 minutes. For seeds (pumpkin seed, sesame, peanut, almond): they are placed on a dry comal over a medium-low heat and moved constantly with a wooden spoon until lightly and evenly golden, 5-8 minutes. For whole spices (clove, pepper, cinnamon, cumin, aniseed): they are toasted briefly for 30-60 seconds on a dry comal until they release aromas. For tortillas: they are heated on a comal over a medium heat for 30 seconds per side to soften them, or longer to make them crisp (totopos). For grains such as cacao: they are toasted whole on a comal until they release aroma and the husks crack, before being peeled and ground. For leaves (epazote, hierba santa): they are toasted briefly to concentrate the flavour. The ideal comal temperature is 180-200°C; too hot, the ingredients burn; too low, the flavours do not develop.

Cultural significance

Toasting on a comal is a fundamental technique of traditional Mexican cooking and part of the UNESCO dossier of traditional Mexican cuisine inscribed in 2010. The comal is one of the most identity-defining symbols of Mexican cooking, comparable to the Asian wok or the European bread oven. Contemporary cooking has revalued artisanal comales: potters of Atzompa, Comonfort, Capula, Mata Ortiz and other regions produce premium comales that are sold in gourmet markets and restaurants. The precise toasting of chillies for mole is a skill passed down from generation to generation among traditional cooks, especially in Oaxaca, Puebla, Tlaxcala and Mexico City. Cooks such as Abigail Mendoza, Margarita Carrillo Arronte and Edelmira Linares have documented and taught the technique. The clay comal has also been recovered by chefs such as Enrique Olvera, Jorge Vallejo and Daniela Soto-Innes in their premium restaurants, where toasting on a comal provides a unique flavour impossible to match with electric or induction griddles. The conservation of traditional comal pottery is a cultural-ecological cause: it protects an ancient craft and cooking techniques that do not pollute or require electricity.

Frequently asked questions

What is the difference between toasting and charring (tatemar)?

Toasting is controlled: the ingredient is heated on a dry comal until lightly browned without burning, aiming to develop flavour without charring. Charring (tatemar) involves partly burning the skin of the chilli or vegetable until it has black spots, with a pronounced smoky flavour. Toasting is applied to seeds, spices and dried chillies where burning would ruin the flavour; tatemado is applied to fresh chillies and vegetables such as tomato and onion.

Why are dried chillies toasted before use?

Brief toasting on a dry comal serves several functions: 1) It softens the skin so it hydrates better in hot water. 2) It activates volatile aromatic compounds that give depth of flavour. 3) It reduces the raw-herb sensation. 4) It concentrates the natural sugars for light caramelisation. 5) It improves the final texture of the salsa or mole. It is an obligatory step in any mole, adobo or traditional dried-chilli salsa.

What type of comal is best?

Traditional glazed clay comales (Atzompa, Comonfort, Capula) provide a subtle mineral flavour and distribute heat evenly, but they are fragile. Wrought-iron comales are durable, make good use of heat and improve with use (they 'season' like a cast-iron pan). Industrial griddles and non-stick pans work but without the flavour of clay or iron. Each traditional Mexican kitchen usually has several comales for different uses.

Where do the comal and toasting come from?

They originate in Mesoamerica, with more than 3,500 years of documented history. The comal was a central utensil of the Aztec, Maya, Zapotec domestic hearth and of practically all the Mesoamerican peoples. The word comes from the Nahuatl 'comalli'. After the conquest, the Spaniards adopted the comal and the toasting technique, which survive throughout traditional Mexican, Central American and south-western US cooking to this day.