Soaking and blending dried chiles — hydration, ratio, technique

Pre-Columbian technique adapted and documented by Diana Kennedy, Rick Bayless, and the Mexican culinary tradition.

After toasting, dried chiles must be rehydrated before blending into sauces, moles, and adobos. The soaking technique directly affects the flavour of the resulting sauce: over-soaking produces a bitter, leached sauce; under-soaking produces a grainy, under-integrated purée. Technique: place toasted chiles in a bowl or saucepan and cover with just-boiled water. The ratio matters — use only enough water to barely cover the chiles, as excess water dilutes the soaking liquid (chile water) which often has valuable flavour. Soak for 20–30 minutes until the chiles are completely pliable and the flesh has softened. Drain, reserving the soaking liquid. Blend the chiles with a small amount of the reserved soaking liquid (not the entire quantity — taste the soaking liquid first; if very bitter, use fresh water or chicken stock instead). Blend to a completely smooth purée, at least 2–3 minutes in a high-speed blender. Pass through a medium-mesh sieve to remove skin fragments and seeds.

• Soaking dried peppers (Spanish cuisine)
• Reconstituting dried cascabel
• Rehydrating ancho for enchilada sauce

The soaking liquid carries dissolved sugars, carotenoids, and capsaicin from the chile. Its bitterness level varies significantly by variety — guajillo soaking liquid is reliably usable; pasilla soaking liquid should be tasted before use.