San Antonio Natural Area Parks
Acorns played an important role in American history as one of the main foods in the diet of Native Americans from coast to coast. The Apaches and Comanches of West Texas, the Tonkawas of Central Texas, and the Caddoan tribes of East Texas all harvested acorns (Newcomb 1961). Most Native Americans and early settlers used acorn meal as flour, as an ingredient in mush or pounded with meat, fat, and berries to make pemmican.
Nutrition: Acorns have protein (about 8 percent) and fats (37 percent) and are high in calcium and other minerals (Crowhurst 1972; Fleming 1975). "Acorns leave a sweetish aftertaste, making them very good in stews, as well as in breads of all types. They are rich in complex carbohydrates, minerals, and vitamins while they are lower in fat than most other nuts. They are also a good source of fiber" (Clay, 2004).
Species: Raw acorns, depending on the species, have a mildly to strongly bitter taste from tannic acid. The Texas oaks reported to have the sweetest taste include Emory oak (Q. emoryi), which is so mild it can be used without processing, white oak (Q. alba), plateau live oak (Q. fusiformis), bur oak (Q. macrocarpa), and chinkapin oak (Q. mulenbergii). The acorns of each of these oaks (mostly white oaks) mature in one year, which may account for their lower tannic acid content. Red oak acorns (like Texas Red Oak) take two years to mature.
Collect the ripe acorns from the ground or spread a sheet under the tree and shake the limbs. Collect three times as many as you think you'll need - expect at least half of them to be molded or infested with insects. "I spread them out as a layer thick on an old sheet which I have laid on a roof, corner of the yard, or some other
out-of-the-way dry, sunny place. This lets them sun dry and prevents any possible molding before I get them shelled. It will also kill any insect eggs or larvae, which might beinside. If you cannot lay the acorns out in the sun, spread them in a single layer on cookie sheets in a very slow oven for an hour." (Clay, 2004)
Shell the acorns as you would any nut. A nutcracker works fine on larger nuts, but you many need to slip open the shell of smaller acorns with a knife. Remove their kernels. If a thin brown corky layer clings to the light-colored flesh, peel off the layer.
To prepare acorns for eating, you need to remove as much tannic acid as possible by leaching with water. Besides being unpalatable, raw acorns consumed in large quantities over time can cause kidney damage. The Indians set the acorns in a basket in a clean fast-flowing stream. (Patty Leslie Pasztor shares that they may have used cactus pouches to hold acorns for leaching.) The water rushing through the basket would leach out the tannins in a day or two. Since most of us do not have a clean fast-flowing stream nearby, we need to boil out the tannins. Toss the nuts into a large pot, and cover them with plenty of water. Bring to a boil and continue boiling for about 15 minutes. The water will turn brown as the tannic acid is extracted from the kernels. Throw out the water and replace it with fresh water. Re-boil the acorns, throwing out the brown water several times until the water is clear. The boiling process takes about two or three hours, though the time varies with the amount of tannic acid in the acorns. When you are finished, the acorns will no longer taste bitter and will have turned a darker brown. The nuts have a flavor similar to boiled chestnuts.
Unless you want to use them wet, you need to dry out the nuts. Spread them out on cookie sheets and roast them in an oven at about 200 degrees F for an hour. You can eat the roasted nuts or chop them up to use as you would any chopped nuts. They can be dipped in sugar and eaten as candy. (Peterson, 1977)
You can also coarsely grind the acorns before leaching. Place the ground acorns in a large crock or glass bowl. Then add boiling water to cover and let stand an hour. Drain and throw away the brownish, unappetizing water. Repeat. Then taste the meal. It should have a bit of a bitter tang and then taste sweet as you chew a piece. Continue leaching out the tannin until the meal is mild tasting. Press and squeeze the meal getting out as much of the water (and tannin) as possible. Spread the damp meal out in a shallow layer on a cookie sheet or on trays of your dehydrator. In the oven, you only need the pilot light or the very lowest oven setting. As it begins to dry, take your hands and very carefully crumble any chunks that hold moisture.
To prepare acorn flour, run the whole or coarsely ground nuts through a food grinder or blender. If the flour still is damp, dry it in the oven for 30 minutes. Then regrind the flour, if needed, to the fineness you want. Use it in breads, either by itself or with other flours. The traditional method was to use a stone (mano in the southwest) hand grinder to crush the meal on a large, flat stone (metate). Use: "I think processed acorns taste like a cross between hazelnuts and sunflower seeds, and I often include acorn meal in my multi-grain bread recipes. Adding half a cup of acorn meal to a two-loaf bread recipe and reducing the flour, as needed, works quite well. Because the
acorn meal is a natural sweetener, I only use a bit of honey to feed the yeast while softening it, relying on the acorn meal to give sweetness to the bread." (Clay, 2004) As acorn meal is very dense, you will have to add yeast or such to get your bread to rise when adding it.
Acorn Meal Recipes:
Steamed Acorn Black Bread
Apache Acorn Cakes
Peggy Spring is Natural Area's Director of Education and Volunteers.