Because we didn’t grow nearly as much wheat as we eat in a typical year, and because we didn't want to put all of our eggs in one basket, we are experimenting with other sources of starch. We grew wheat, grain sorghum, field corn, two types of potatoes, an obscene quantity of sweet potatoes, and we foraged for acorns.  Unlike potatoes and sweet potatoes, acorns are intriguing as another possible source of flour.

While we are not experts, we have been harvesting and experimenting with acorn processing more than we have in years past, and will know a lot more by year’s end.

First, a big thank you to all those who have documented how to collect and process acorns. If you haven’t read the remarkably comprehensive chapter in Samuel Thayer’s Forager’s Harvest, this is the place to start. As with all of his work, this is a work of extensive experience, and his voice is unique and always reliable. His overview on how to identify good acorns is a must-read prior to harvesting. Another shout-out goes to Hank Shaw at honest-food.net for his account of acorn processing and recipes. Also, there’s a marvelous book of recipes aptly titled Eating Acorns by Marcie Lee Mayar.

So far we collected White oak, Burr oak & Northern red oak acorns.

De-hulling & Drying

Burr oak acorns are the largest in the country and are relatively low in tannins. The down-side is there is a learning curve on de-hulling. We made the mistake of drying to the point that the huge hulls became impossible to pry off, and then we cracked them with a hammer and pulled them apart (see video clip below). This was somewhat dangerous, and not fun. Next, we left the acorns to dry on shallow racks in our house, heated by a wood stove. Over the course of the next several weeks, we discovered they were rotting before they had a chance to dry. So, we cut them into pieces. The pieces are drying quickly, and this seems like what we should have done at the outset.  In fact, we should cut them into quarters the day we gather them, getting the hulls off at that time.  Larger pieces won't fit in the grinder, and are rock hard when dry.

Had we cut them in half while still in their hulls, this would have saved a lot of work! Next year...

As for other types of acorns, red oak acorns are small and can be left in their shell to dry whole.  White oak acorns sprout in the fall, so its best to expedite the drying by cutting them in half and shelling them as soon as possible after collecting.  Both types can be easily cut in half with a good knife, or even garden shears when fresh.

Drying Acorns /\

Acorns have to be leached of their tannins in order to render them edible. There are two basic means of leaching: hot and cold leaching. Hot leaching is quicker, but changes the protein structure and the resulting flour will behave even less like wheat flour than cold-leached acorns. Hot leaching works great if you intend to eat something like acorn grits or other things where you don’t need flour to stick together.

Cold leaching

We have experimented primarily with cold-leaching. At first, we blended fresh burr oak acorns with water using our high-powered vita-mix until the acorns were gritty, but not blended super-fine. The resulting slurry was placed with more water in a large jar, and kept cold in the fridge. Several times daily, we poured off water, and re-filled with clean water. When a taste-test revealed they were done, we dried the acorn meal. This was ground further into flour, and then used to bake.

Now we just grind the dried acorns in our corn grinder (that we scored from an auction - thank you Johnny for spotting this gem!).  This works well and I'm not worried about overworking my hand-me-down Vitamix.

We also switched to our new preferred method of pouring the water-acorn meal slurry into a cloth bag or pillowcase, which we keep in the bath-tub and top-off with fresh water several times daily. This allows more constant and efficient cold leaching, and so the whole process is faster.  In one to three days, leaching is complete.

The bur oak acorns are surprisingly low in tannins, and two days seems like overkill honestly.

Drying and Grinding - the final steps in Acorn Processing

In winter months, we dry the wrung-out acorn meal over the wood stove before grinding. Dried acorn flour should be stored in the refrigerator to prevent the fat from going rancid. For this reason, small batches should be made at a time.

So far our favorite things to make with acorn flour are acorn crackers, which we prefer to regular wheat crackers, acorn crusts for quiches and pies, and muffins and quick breads.  The flavor is nutty and delicious, and food made with acorn flour are higher in protein and more filling.

For our recipe and detailed instructions on making acorn crackers, click here!