 |
| Just a few of these hefty acorns make a handful |
It has been several
years since I collected Red Oak (Quercus rubra) acorns, and never in the Pacific Northwest.
This year they masted heavily near my house and my Garry Oak supply just
ran out, so I figured it was time to reconnect with the first acorn I ever ate. Last month I collected 5 gallons of large
acorns in just a few hours, and have recently just finished drying and shelling them.
This post includes a detailed description of Red Oak along with some ethnobotanical
notes, and my experiment with a new (to me) method of leaching acorns.
 |
| Red Oak in its native range along the Wisconsin River |
Wild Red Oak populations
range from Minnesota eastward to Nova Scotia and southward from eastern
Oklahoma through most of Alabama, and the northern half of Georgia, South
Carolina and North Carolina. Two varieties are currently recognized by botanists: Q. rubra var rubra has a more southerly distribution and larger, rounder acorns, and Q rubra var borealis has a more northerly distribution and smaller, more oblong acorns. Though not native to the Pacific Northwest, Red
Oak are frequently
planted at college campuses, cemeteries, and along streets. They are actually
far more common near my house than our native Garry Oak (Quercus garryana).
 |
| Brilliant foliage on a fine fall day |
Description
In our region, Red Oaks
trees generally have straight trunks with spreading to upright branches and a
rounded crown. They mature to 60-90 feet tall and can grow 4-6 feet in
diameter, but as most of those in the Pacific Northwest are less than 100 years
old, trees greater than 3 feet in diameter are rare, despite rapid growth rates.
 |
| Red Oak bark |
Bark is grey and cracks
into relatively smooth plates separated by long, shallow, vertical fissures.
Twigs are reddish brown
and smooth. Buds are reddish brown, egg shaped, and ¼ inch long.
The deciduous leaves arise alternately
on the branch and range in size from 3-12 (15) inches long and a little more than
half as wide. Margins have pointed tips (like all oaks in the red oak group)
with 1-5 sharp teeth on each of the 5-9 (usually 7) evenly space lobes with
u-shaped troughs that extend a third to half the distance towards the midvein.
Leaf bases taper abruptly to a ¾-1.5 inch long petioles. Fall foliage ranges
from yellow to scarlet to bronze and some trees will hold dead leaves into the winter. Upper leaf surfaces are smooth and slightly glossy, and lower
surfaces are smooth with conspicuous veins that are sometimes hairy.
 |
| A lineup of leaves |
Red
Oak acorns are the quintessential North American acorn with a fairly round
shape and shallow saucer to cup shaped cap. Shells range in size from 5/8- 1
1/8 inch wide and 1-1.5 times as long. Shell color ranges from yellowish brown
to green to purplish red, and the shells are sometimes covered with very fine
silver hairs. Caps only cover 1/3-1/4 of the shell or less, and have a scaly top.
 |
| Size gradation of two Red Oak acorn varieties |
The US
Forest Service
Fire Effects
database reports that Red Oak acorns contain 1300 calories per pound with
roughly 5 percent protein. Kuhnlein and Turner (1991) found 7.2 g of protein,
14.5 g of fat and 65.7 g of carbohydrate per 100 grams of fresh acorn. However, acorns are high in tannins with levels ranging from
4-16
percent.
Eaten
as a staple food by the Anishinabe (Ojibwa), Dakota, Haudenosaunee (Iroquois),
Omaha, Pawnee, Ponca, Potawatomi (see
Native American Ethnobotany)
and likely all the Indigenous Peoples living within the plants range. The
bitter tannins are traditionally leached with the aid of wood ash or lye and
cooked into gruel.
 |
| Smith's image of edible acorns species |
Early ethnobotanist Huron Smith (
1923, pg 66) documented the Menominee method of processing various oak species: "The hulls were flailed off after parching, and the acorn was boiled till almost cooked. The water was then thrown away. Then to fresh water, two cups of wood ash were added. The acorns were put into a net and were pulled out of the water after boiling in this. The third time, they were simmered to clear them of lye water. Then they are ground into meal with mortar and pestle, then sifted in a birch-bark sifter. The fourth time, the meal is cooked in soup stock of deer meat until finished and ready to eat, or made into mush with bear oil seasoning. The old Indians never made pie, but the Menomini now make pie of them."
 |
| Shelled Red Oak acorns |
Processing
 |
| Cracked acorns |
I’ve written previously
about how I dry, crack, and winnow my acorns (see
How to Eat
an Acorn), but I thought I would pass on another leaching method that Sam
Thayer recently told me about called percolation leaching. The technique is
modeled after California Native American acorn leaching whereby finely pounded acorn flour is placed on a shallow depression in the sand that is repeatedly filled with water.
 |
| Cracking acorns with a Davebilt Nutcracker |
 |
| Finished Red Oak acorn flour |
References
Pin It
The deciduous leaves arise alternately
on the branch and range in size from 3-12 (15) inches long and a little more than
half as wide. Margins have pointed tips (like all oaks in the red oak group)
with 1-5 sharp teeth on each of the 5-9 (usually 7) evenly space lobes with
u-shaped troughs that extend a third to half the distance towards the midvein.
Leaf bases taper abruptly to a ¾-1.5 inch long petioles. Fall foliage ranges
from yellow to scarlet to bronze and some trees will hold dead leaves into the winter. Upper leaf surfaces are smooth and slightly glossy, and lower
surfaces are smooth with conspicuous veins that are sometimes hairy.
