On our way back north through the
Central Valley, I kept my eye out for Valley Oak (Quercus lobata) and was lucky enough to find a few trees only a
short distance from the highway near Cottonwood California.
 |
| This fine grove has been pruned of their lower limbs |
Valley Oaks are the largest of our North
American Oaks often reaching 100 feet tall and more than 5 feet in diameter.
Open-grown trees have widely spreading, gnarled branches and rounded crowns,
giving the tree a silhouette that is often wider than it is tall. The branches
on older trees have a noticeable drooping quality near the tips. The bark is
light to dark grey with long braided fissures (more widely spaced than those on Blue
Oak bark) that break up into a smaller mud crack or alligator skin pattern
(like Garry
Oak bark) in large specimens. Leaves are deciduous and are typically 2 to 4
inches long with deep rounded lobes. Both surfaces are densely covered with soft
fuzz; the top is green and the bottom is much paler. Their range is limited to
the Central Valley and Coastal California below about 2000 feet in elevation
where they thrive in deep alluvial soil in places with access to year round
moisture.
 |
| A few remaining leaves in early winter |
Acorns typically arise singly but
occasionally grow in pairs, and are 1.5-2.5 inches long and ½-1 inch wide,
making them among the largest acorns in North America. Caps are warty and cover
the top ¼ inch of the acorn. The cap scar is typically ¼ inch wide, from which
point the acorn tapers out abruptly, reaching its widest point in the upper ¼-⅓ of
the acorn, and then tapering gradually to a long point. The acorns
lack symmetry on a longitudinal axis. Those acorns which are not consumed will
sprout during winter rainstorms. Shells are thin and crack the length of the
acorn as the hypogeal growth pushes through the shell and roots deeply into the
ground, and it is not unusual to find a few acorns shells that have pealed
completely off of the nutmeat. Valley Oak acorn nutmeat is a light buttery
yellow color with a surface that is frequently stained pink, red, or purple where it has been
exposed to the air. The nutmeat around the sprouting tip may also be stained
green or brown.
 |
| Moderately sized Valley Oak acorns (scale in cm) |
Valley Oak acorns are a traditional food
used extensively by California Native Americans. The large acorns are collected
in the fall and stored for use throughout the rest of the year to make bread, soup,
and mush. As with all acorns, the tannins must be leached from the nuts before
they can be eaten and the California Native Americans did this by grinding them
into flour using a mortar and pestle, and then leaching them with cold water.
Victor Chestnut (1902) documented the
traditional use of Acorns by the Native Americans living in the Mendocino
County area. He observed that Valley Oaks were among the most prized of the
many acorn-bearing species in the area, due to the high fat content, large acorns, and the shared preference by both human and nut to grow
deep roots in the fertile valley bottoms.
Chestnut alluded (pg 334) to the use of
leaching pits in which whole acorns are buried in a sandy place with grass,
charcoal, and ashes, and then flushed with water from time to time to remove
the bitter tannins from the acorns. However, most of his account detailed the process of pounding the acorns into a very fine flower,
spreading the flour on a bowl-shaped bed of compacted sand, and gently deluging the reservoir with water, which upon percolating through the acorn flour over the course of a few hours, removes the tannins.
 |
| A Hupa woman leaching acorns by a similar method. Photo from Goddard 1903, plate 15. |
Evidently, any sand that may mix with
the acorn flour is not an issue when the flour is used to make soup, as the heavy
sand settles to the bottom of the cooking basket where it can be avoided. When bread is being made, a layer of leaves or more
recently, cloth, is sometimes spread over the sand before the flour is laid
out. Acorn bread is made by mixing in roughly 5 percent clay by mass. With moderate success, Chestnuts
investigated the effect of iron oxide rich clay on the remaining tannin in
the bread, and also suggested that the clay absorbs oils that
would otherwise be lost, gives the bread an agreeable color, and adds beneficial
minerals to the diet.
Terminology
related to Valley Oak acorns
Pä’·önsh (Yuki): Bread
made from Valley Oak
Sē-pä’ (Litle Lake):
Valley Oak acorn
Skin’chön (Wailaki):
Valley Oak acorn
Kī-yäm’ (Yuki): Valley Oak
acorn
Lō-ē’ (Concow): Valley Oak
acorn
Acorns comprised a large part of the traditional
diet of California Native Americans. Chestnut observed that a single family
would collect about 500 lbs of acorns for the year. In 1986, DA Bainbridge
reported that a single Valley Oak trees is capable of producing as much as
2,000 lbs of acorns in a year (see “Use
of Acorns for Food in California: Past, Present, and Future”).
In less than five minutes I was able to
collect about a quart of moderately sized Valley Oak acorns to use for my own culinary
experiments. Back home they are now drying on a large baking sheet in my small apartment. They constantly
remind me of the life-sustaining promise that has been endowed upon the many landscapes
throughout the Pacific Northwest. Not only is each nut edible, but each holds the
potential to produce hundreds of tons of food.