One of the mainstays of the diet for the California Indians was the acorn which was used in soup, porridge, and bread. Sixteen different species of oak provided the acorns. There are a number of steps involved in gathering and processing the acorns. They are gathered in September and October. Traditionally, the people gathered the acorns by climbing the tree and then beating off the nuts with a long slender pole.Harvesting would take place over a fairly short period of time, about two or three weeks.
The acorns which are collected have white bottoms and no insect holes. The acorns are then dried in their shells, a process which takes anywhere from a few weeks to a few months. During this time, the acorns are stirred to increase air circulation and encourage drying.
Once dry, the acorns are cracked to remove the nutmeat. This was traditionally done with a small, handheld stone pestle. The acorns are then ground or pounded into acorn flour. The flour is pounded as fine as possible. Once the acorns are ground into flour, they are then leached. Acorns contain tannic acid which is very bitter and which is poisonous in large amounts. The leaching process removes the tannic acid from the acorn flour. The leaching was traditionally done by digging a shallow sand pit near a creek. The flour was then carefully spread in the bottom of the pit and was continuously poured over it until it was sweet. It would take several hours of pouring to leach the flour.
One of the displays in the Riverside Metropolitan Museum in Riverside, California, is entitled Food for Life. According to the display:
“Once food had been gathered, Southern California Native Americans used many tools to prepare meals for their families. Acorns were hulled and ground on stone mortars, leached to rid them of bitter tannic acid, and cooked in large baskets. Cooking baskets were filled with water and acorn flour, hot stones were lifted into the baskets to cook the acorn mixture, making wiiiwish. Today, wiiwish is still eaten by Southern California Native Americans.”
Shown above is a Mountain Cahuilla cooking basket made about 1890. Shown above is a hot stone lifter which was used to lift hot stones into the basket for cooking. Shown above is a Luiseño basket hopper and stone mortar. The basket hopper, attached to the mortar with tar, would keep the acorns in the mortar while grinding them.
The Luiseño used six different species of acorn and their located their villages near water resources so that they could leach the acorns.