Saturday, November 5, 2016

Eating Acorns

Note: This program first aired November 5, 2016.

Food anchors us to the land(*), it places us in a landscape and timescape. Food also anchors us in our community. We share a common language with those who eat the same things we do, and food gives us a currency with which to exchange culture with people with different traditions.

I never feel more human than I do when I am eating wild foods. Whether it is incorporating a daily morning berry foraging walk that provides my summer breakfast, harvesting and tincturing a medicinal herb to support a loved one’s health, stumbling on an edible fungus in the fall or collecting favorite algae at the sea shore, nourishing myself from uncultivated yet bountiful sources feeds something as old as time in me.

I don’t as of yet hunt animals, so the wild food gathering I undertake is primarily focused on plants. With this in mind I signed up for a class with Arthur Haines, a well respected botanist here in New England and passionate and generous advocate for the wild food and rewilding movement. Our topic was acorns, how to collect, preserve, process and enjoy this at times prolific nut.

I was delighted to hear Arthur sing the praises of the Northern Red Oak acorn (Quercus rubra), a member of the Black Oak subfamily that includes Scarlet Oak, Pin Oak and many others. I live in a Red Oak forest, the acorns literally drop onto my door step in the fall. Northern Red Oak acorns are distinguished by their nutritional profile, they are nearly 50% lipid (or fat). Crack open a fresh Red Oak acorn and you will feel the oiliness on your fingers. That fat is mainly oleic acid, the same monounsaturated fatty acid that is found in olive oil. The rest of the bulk of the nut is complex carbohydrate, and a small percentage of protein.

The process of using acorns for food begins with gathering and sorting. It turns out not all acorns are created equal. Some are damaged right from the start, fail to develop to full size and are shed by the tree early. Others look like regular acorns, but when hefted in the hand reveal a lighter than average weight. They weigh less because they are hollow, or are in the process of becoming hollow.  They are hollow because they are being eaten from the inside out by the larva of the acorn weevil, a small beetle that lays its eggs in the developing acorn. As the acorn approaches maturity, the egg hatches and the tiny larva, now housed inside its own food source, begins to eat. As it eats, it also respires, and just like we exhale carbon dioxide and water, so does the larva. That gas has mass and dissipates through the acorn shell, so as the larva eats the acorn, the acorn gets lighter and lighter. Once the larva has eaten all of the goodness inside, it exits the acorn through a little hole it creates---thus any acorn you find with a tiny circular hole in the side is no good—it is just full of acorn frass. Any acorn you find without the tell tale exit hole, that feels feather light, much lighter than all the others in your hand-if you cracked that one open it is likely you would find a number of acorn weevil larvae still munching away inside.

We can’t just shell an acorn and pop it into our mouths, and this is something aboriginal populations world wide figured out thousands of years ago. Acorns contain tannins, a group of chemicals that yield both a bitter taste and an astringent feel in the mouth. Primarily thought of as a defensive compound for the plant,  some tannins have anti nutrient properties, while others (like the ones in tea) have strong nutritionally beneficial anti oxidant properties. The tannins in acorns are of the former variety, and make them in their unprocessed state, an unpleasant eating experience.

The processing may be one reason these native nuts have fallen out of favor, after drying, cracking and shelling, you still have to chop or grind them and then leach out the tannins. The process, though not intensive throughout, takes weeks. The result at the end though is a relatively bland flour, with a high healthy lipid content, and a very low glycemic index, suitable to mixing in with other flours in baked goods, or eating as a hot cereal with maple syrup. If you like getting connected with your food source, aren’t afraid a little work and are up for a culinary adventure, this would be a good year to try eating acorns. For many of us in eastern Maine, they are falling on our doorsteps.


On acorn weevils from Iowa State Extension service:

Encouragement from the Earth Island Journal for eating acorns at Thanksgiving:

Delta Institute of Natural History (and website of Arthur Haines, the botanist and wild food advocate mentioned in the program):  *The first line of this show (about food anchoring us to the land, comes from Arthur’s description of the acorn workshop)

There are lots of references online for how to process acorns, some using hot water to leach the tannins, others using cold. Some crack the nuts immediately, others dry the acorns first (they are A LOT easier to shell if dry, and can be stored dry in the shell for years). The work shop I attended emphasized making the process efficient, but regardless—go ahead and experiment! There’s lots of info out there to get you started!