What You Need to Know
The process uses a flat stone slab (metate) and a cylindrical stone pestle (mano) to apply shear forces that fracture the crystalline structure of starch granules, increasing their susceptibility to gelatinization during cooking. Friction generates a modest temperature rise of 20–30 °C on the slab surface, which can transiently affect enzymes such as α‑amylase in the kernels. This mechanical treatment is a foundational step in Mesoamerican staple food production.
The Science
Primary Reaction
Mechanical disruption of starch granules (physical breakdown)