Frijoles de olla — "beans from the pot" — the foundation of Mexican daily cooking — are dried beans (black, pinto, ayocote, flor de mayo depending on region) slow-cooked in water with onion, garlic, lard, and epazote until completely tender and the cooking liquid has thickened into a savoury, fragrant broth. The beans' own starch, dissolved into the liquid during the long cooking, produces the characteristic body — no thickening agent is needed.
- **Never soak (the Mexican preference):** Many Mexican traditions cook beans from completely dried, without soaking — the argument that soaking produces a waterlogged bean that loses flavour to the soaking water. The no-soak beans absorb the cooking water's aromatics directly. Cooking time increases substantially: 2–3 hours for unsoaked beans. - **Epazote (Chenopodium ambrosioides):** The essential herb for black bean preparations — its distinctive, slightly medicinal, complex aromatic profile (specifically its ascaridole terpene compound) is the flavour that makes Mexican black beans taste specifically Mexican. Epazote also reduces the gas-producing oligosaccharides in beans. [VERIFY] Arronte's epazote specification. - **Lard (manteca):** Traditional fat — added to the cooking water, it infuses the beans' exterior during cooking and contributes to the broth's richness. - **Salt timing:** Added only in the final 30 minutes — salt added earlier slows the softening of the bean's cell walls (calcium in the salt binding with the pectin). Some cooks dispute this; Arronte's position should be verified. [VERIFY]. - **The frijoles refritos technique:** Cooked beans are fried in lard in a hot pan, mashing progressively as they cook. The mashing and frying together produce refried beans — not pre-boiled beans, but a preparation in which the beans are simultaneously broken down and fried in fat.
Mexico: The Cookbook