Tacos de Asador ("spit" or "grill" tacos) may be composed of any of the following: carne asada tacos; tacos de tripita ("tripe tacos", grilled until crisp; and, chorizo asado (traditional Spanish style sausage). Each type is served on two overlapped small tortillas and sometimes garnished with guacamole, salsa, onions, and cilantro. Also prepared on the grill is a sandwiched taco called mulita ("little mule" made with meat served between two tortillas and garnished with Oaxaca style cheese. "Mulita" is used to describe these types of sandwiched tacos in the Northern States of Mexico, while they are known as Gringa in the Mexican south and are prepared using wheat flour tortillas. Tacos may also be served with salsa.
Tacos de Cabeza or head tacos, in which there is a flat punctured metal plate from which steam emerges to cook the head of the cow. These include: Cabeza, a serving of the muscles of the head; Sesos ("brains" Lengua ("tongue" Cachete ("cheeks" Trompa ("lips" and, Ojo ("eye". Tortillas for these tacos are warmed on the same steaming plate for a different consistency. These tacos are typically served in pairs, and also include salsa, onion and cilantro with occasional use of guacamole.
Tacos de Cazo for which a metal bowl filled with lard is typically used as a deep-fryer. Meats for these types of tacos typically include: Tripa ("tripe", usually from a pig instead of a cow); Suadero (tender beef cuts), Carnitas and Buche (Literally, "crop", as in bird's crop; here, it is fried pig's esophagus.)
Tacos sudados ("sweaty tacos" are made by filling soft tortillas with a spicy meat mixture, then placing them in a basket covered with cloth. The covering keeps the tacos warm and traps steam ("sweat" which softens them.
Tacos de suadero (grey) and chorizo (red).
Tacos Al pastor/De Adobada ("shepherd style" are made of thin pork steaks seasoned with adobo seasoning, then skewered and overlapped on one another on a vertical rotisserie cooked and flame-broiled as it spins (analogous to the Döner kebab used in Greek restaurants to prepare gyros).
Tacos dorados (fried tacos, literally, "golden tacos" called flautas ("flute", because of the shape), or taquitos, for which the tortillas are filled with pre-cooked shredded chicken, beef or barbacoa, rolled into an elongated cylinder and deep-fried until crisp. They are sometimes cooked in a microwave oven or broiled.
Tacos de pescado ("fish tacos" originated in Baja California in Mexico, where they consist of grilled or fried fish, lettuce or cabbage, pico de gallo, and a sour cream or citrus/mayonnaise sauce, all placed on top of a corn or flour tortilla. In the United States, they remain most popular in California, Colorado, and Washington. In California, they are often found at street vendors, and a regional variation is to serve them with cabbage and coleslaw dressing on top.
Tacos de camarones ("shrimp tacos" also originated in Baja California in Mexico. Grilled or fried shrimp are used, usually with the same accompaniments as fish tacos: lettuce or cabbage, pico de gallo, avocado and a sour cream or citrus/mayonnaise sauce, all placed on top of a corn or flour tortilla.
As an accompaniment to tacos, many taco stands will serve whole or sliced red radishes, lime slices, salt, pickled or grilled chilis (hot peppers), and occasionally cucumber slices, or grilled cambray onions.
Beginning from the early part of the twentieth century, various styles of tacos have become popular in the United States and Canada. An early appearance of a description of the taco in the United States in English was in a 1914 cookbook, California Mexican-Spanish Cookbook, by Bertha Haffner Ginger. The style that has become most common is the hard-shell, U-shaped version described in a cookbook, The good life: New Mexican food, authored by Fabiola Cabeza de Vaca Gilbert and published in Santa Fe, New Mexico in 1949. These have been sold by restaurants and by fast food chains. Even non-Mexican oriented fast food restaurants have sold tacos. Mass production of this type of taco was encouraged by the invention of devices to hold the tortillas in the U-shape as they were deep-fried. A patent for such a device was issued to New York restaurateur Juvenico Maldonado in 1950, based on his patent filing of 1947 (U.S. Patent No. 2,506,305). Such tacos are crisp-fried corn tortillas filled with seasoned ground beef, cheese, lettuce, and sometimes tomato, onion, salsa, sour cream, and avocado or guacamole.
Traditionally, soft-shelled tacos referred to corn tortillas that were cooked to a softer state than a hard taco - usually by grilling or steaming. More recently the term has come to include flour tortilla based tacos mostly from large manufacturers and restaurant chains. In this context, soft tacos are tacos made with wheat flour tortillas and filled with the same ingredients as a hard taco.
Puffy tacos, taco kits, breakfast tacos and tacodillas
Since at least 1978, a variation called the "puffy taco" has been popular. Henry's Puffy Tacos, opened by Henry Lopez in San Antonio, Texas, claims to have invented the variation, in which uncooked corn tortillas (flattened balls of masa dough) are quickly fried in hot oil until they expand and become "puffy". Fillings are similar to hard-shell versions. Restaurants offering this style of taco have since appeared in other Texas cities, as well as in California, where Henry's brother, Arturo Lopez, opened Arturo's Puffy Taco in Whittier, not long after Henry's opened. Henry's continues to thrive, managed by the family's second generation.