Grinding on the metate: the heart of masa and moles

What is it?

Grinding on the metate is the oldest food-processing technique in Mesoamerica, present for at least 8,000 years. The metate, a rectangular stone carved in basalt or volcanic andesite, together with its hand (metlapil or roller), allows grinding of nixtamalised maize to make masa, grinding cacao and spices for chocolate, preparing mole pastes and crushing dried chillies. The friction of stone against stone produces a fine, slightly warm grind that releases essential oils and develops aromas that no modern mill achieves. Although today it coexists with electric mills, in traditional kitchens the metate remains the tool of choice for blue masa, Oaxacan mole, table chocolate and other products where artisanal texture and deep flavour are sought.

Origin and history

The metate is one of the oldest utensils in Mesoamerica, with archaeological evidence dated to 6000 BC in caves such as Tehuacan, Puebla, and Coxcatlan. Its basic form (concave stone on three legs and a roller) remained practically unaltered for millennia, proof of its functional perfection. Pre-Hispanic codices such as the Mendocino and Florentine represent women grinding on the metate, a central activity of the domestic economy of the Nahua, Maya and Mixtec. Fray Bernardino de Sahagun describes in detail the use of the metate in female tasks (the temazcalli and the metate were socialisation spaces). After the conquest, the metate survived the introduction of European mills due to its superiority for grinding cacao and nixtamal. The National Institute of Anthropology and History (INAH) has documented that the metate remains a living tool in towns of Oaxaca, Guerrero, Chiapas and Puebla, where it is carved by specialised artisans of generations.

Characteristic ingredients

The traditional metate measures between 40 and 70 cm long, 25 to 40 cm wide, is carved from a single piece of volcanic rock (basalt, andesite) and has three legs to tilt forward. Its grinding surface is not smooth: it has a slight porosity that allows it to grip the grain. The metate hand (metlapil) is a stone cylinder of the same material, about 30 to 40 cm. Before being used, the new metate is cured: salt, dry maize or rice is ground several times until the stone releases particles and is fit for food. The technique consists of kneeling in front of the metate and pushing the hand with the full weight of the body, in long, firm movements. Different ingredients require different grinding: nixtamalised maize is ground with water a little at a time; toasted cacao is ground hot to release the butter; dried chillies are ground toasted with spices for mole. Grinding on the metate releases volatile oils and develops nuances that a mechanical mill does not produce.

Cultural significance

Grinding on the metate is a practice and symbol of traditional Mexican cuisine, recognised by UNESCO as Intangible Cultural Heritage of Humanity in 2010. In indigenous communities, knowing how to grind on the metate is a central skill of the female culinary role, passed on from mothers to daughters over generations. The strength, rhythm and tactile sensitivity it requires are bodily learnings that are refined over the years. In Oaxaca, traditional cooks still grind mole on the metate for major celebrations (weddings, patronal feasts), considering it the only authentic method. The table chocolate of Oaxaca and Tabasco is still made on a hot metate over coals. The metate also has ritual value: it appears on Day of the Dead altars and is inherited as a precious good among women. Contemporary Mexican cuisine has rescued the metate as a symbol of authenticity, present in fine-dining restaurants and gastronomic festivals.

Frequently asked questions

What is the difference between grinding on a metate and on a mill?

The metate grinds by friction and crushing between two porous volcanic stones, slightly heating the product and releasing essential oils and aromas that give deep flavour. The industrial mill cuts and chops with metal blades or discs, produces faster but gives a more uniform grind that is flatter in flavour. The artisanal texture of the metate is irregular and complex.

What does food ground on a metate taste like?

It has a deeper and more aromatic flavour than the industrial version. The maize masa has toasted notes, is slightly granular and has a better consistency for hand-made tortillas. Metate chocolate develops intense toasted aromas and keeps the cacao fat integrated. Moles gain complexity from the release of oils from chillies and spices.

How is a new metate cured?

Before first use it must be cured: several batches of abrasive grains (coarse salt, raw rice, dry maize) are ground over days until the stone stops releasing grit. Then it is rinsed, dried in the sun and is ready. After each use it is only cleaned with water and sometimes a natural fibre brush; never with soap or detergents.

Where is the metate from?

The metate originates from Mesoamerica, with archaeological evidence of at least 8,000 years in caves of Tehuacan (Puebla) and Coxcatlan. Today it is carved artisanally in towns of Comonfort (Guanajuato), Puente de Ixtla (Morelos), Etla and the Mixteca (Oaxaca), where master stone carvers preserve techniques inherited from the pre-Hispanic era.