The meat is marinated in an adobo made of vinegar, dried chiles, garlic, and herbs and spices (including cumin, bay leaves, and thyme) before being cooked in a broth (Spanish: consomé).

[8][11] The term birria was originally the regional name given in Jalisco to meats cooked in a pit or earth oven, what is known in other parts of Mexico as barbacoa.

[16] Mexican writer and essayist Jorge Mejia Prieto defined it in 1985 as a "soupy barbacoa made with lamb or goat meat from Guadalajara, Jalisco".

One such story argues that in 1519, Hernán Cortés and the Conquistadors first landed in Mexico,[18] bringing various old-world domestic animals, including goats.

The dishes they produced were called "birria", a derogatory term meaning "worthless", by the Spanish, in reference to their having given the natives meat with apparently noxious characteristics.

[19] According to another legend, the dish was invented accidentally during the eruption of a volcano, when a shepherd was forced to abandon his goats in a cave where they were cooked perfectly by the steam.