Tamales made with ash-treated corn masa, giving them a distinctive blue-gray color and unique flavor. This traditional vegetarian family recipe preserves an ancient Mexican technique.
Place the dried corn kernels and wood ash in a large pot with water. Bring to a low boil, then simmer for 1 hour, stirring occasionally to prevent sticking.
Drain and rinse the corn thoroughly under cool water, rubbing off the loosened hulls until the kernels are smooth and slip free.
Grind the prepared corn using a food processor or molino until you achieve a moist masa with a fine, slightly gritty texture.
Mix masa with vegetable shortening and salt in a large bowl. Knead by hand until silky and pliable, adding a little warm water if necessary to keep the dough soft.
Soak the corn husks in warm water for 30 minutes until pliable. Drain and pat dry.
Spread 2–3 tablespoons masa onto each husk, leaving space at the edges, and fold tightly to enclose.
Arrange tamales upright in a steamer lined with extra husks. Steam over low heat for 1.5–2 hours, checking water level and adding more as needed, until tamales are set and pull away cleanly from the husk.
Let tamales rest for 10 minutes before serving, which helps them firm up and develop their signature texture.