Tacos

The corn tortilla is one of the oldest continuously eaten foods in the Americas. It depends on nixtamalisation, a process developed in Mesoamerica in which dried maize is cooked and steeped in an alkaline solution of lime or ash. This softens the grain for grinding, improves its aroma, and — crucially — unlocks nutrients that are otherwise unavailable, making maize far more nourishing as a staple.

Wrapping food in a tortilla is presumably as old as the tortilla itself. The word taco, however, appears in this culinary sense only in the nineteenth century. A widely repeated explanation links it to Mexican silver miners, who used the term for the paper-wrapped charges of gunpowder they packed into rock faces; a filled tortilla resembled one closely enough for the name to transfer.

A taco is a format rather than a recipe, and the variety is enormous. Tacos al pastor layer marinated pork on a vertical spit — a technique brought by Lebanese immigrants to Mexico and adapted with chillies and pineapple. Carnitas are pork slowly confited until tender and crisped at the edges. Barbacoa is pit-cooked meat, traditionally wrapped and buried with hot stones. Fish tacos are a speciality of the Baja California coast.

The seasoning is usually restrained on the meat and lively on top: raw onion, coriander, a squeeze of lime, and a salsa chosen to match. Two small tortillas are often stacked under a wet filling for structural reasons that anyone who has eaten a collapsing taco will appreciate.

In Mexico tacos are typically small, eaten standing, and bought several at a time from a stand that specialises in one style. The taquero's skill lies in consistency and speed, and a good stand will have a queue that regulates itself.

North of the border the taco evolved separately into the hard-shell, ground-beef, lettuce-and-cheddar version that became an American staple in the mid-twentieth century. It is a genuine culinary tradition in its own right, but it is a distinct one, and the difference between it and a Mexico City street taco is a useful reminder of how far a dish can travel from its origin while keeping the name.