Sour Orange (Naranja Agria)

Sour orange is a variety of orange with a very tart and bitter flavour, indispensable in Yucatecan cooking. It is the acidic component of cochinita pibil, pollo pibil, and Yucatecan ceviche. When unavailable, it is substituted with a mix of lime, orange, and vinegar, though the result is never quite the same.