When the caps and shells are removed, the nuts are high in protein, potassium, magnesium, calcium and vitamin B6. They are naturally gluten-free and loaded with fiber. There are more than 400 species of oak trees grown around the world, and the acorns they produce vary in color, flavor and size. They naturally contain tannic acid, a water-soluble bitter substance that leaches out during processing, allowing their natural sweetness to come forward.
Acorn flour is still very much a specialty ingredient; however, it is gaining traction on local levels. Sue Chin, owner of Sue´s Acorn Cafe & Mill, Martinez, California, U.S., for example, collects local acorns to produce her own flour. She uses it to create an array of baked foods served at her restaurant and sold on-line. Offerings include biscotti, bread, cakes and muffins. She also sells the acorn flour for home baking.
On Kea Island in Greece, Marcie Mayer, a California native, heads up the Oakmeal Acorn Initiative, a multifaceted project to help farmers rekindle the collection of acorn caps for exportation to tanneries, as well as establishing acorn flour-based products in the local cuisine.
The use of acorn flour in Mediterranean cuisine is developing. Mayer currently produces and markets a line of acorn cookies and acorn pasta.
“Acorn flour behaves very differently than wheat flour,” she said. “It has a darker color and much richer aroma. It is typically blended with wheat flour.”
A driving force behind the increase in popularity of variety flours is consumers’ desire for food with a story or a connection to a faraway place or foreign culture. Acorn flour, for example, is a staple in much of Asia, particularly in Korean baking and cooking.