Red Oak Recipes: Acorn Cakes

By Guest blogger Heidi Leuszler, Pastry Chef at Berries & Flour

Last year on Oct 23, 2019, campus and community gathered to celebrate the completion of the Red Oak Rain Garden’s Phases I and II. We served special cakes made with some ingredients grown at the garden, including the red oak’s acorns. To mark this anniversary, Pastry Chef Heidi Leuszler shares her method of making acorn flour. Photos are hers except for the featured photo by Della Perrone.

I was honored when asked to make cakes for the Red Oak Rain Garden’s event last year. I have been watching it grow and knew that the RORG Team included edible native species into the planting plan, so I made cakes that incorporated these species: Vanilla Spicebush (Lindera benzoin) and Acorn Aronia (Quercus rubra and Aronia melanocarpa). Of these ingredients, the most uncommon is the acorn flour, so this blog shows how to make it.

MAKING ACORN FLOUR

Step 0: Collect the acorns as soon as they fall to the ground. You want large acorns to make the most of your work. Luckily, the red oak produces some of the larger acorns in the area. The RORG Team foraged a bag of acorns and brought them to me.

Step 1: To separate the sound (good) acorns from the empty (bad) ones, I soaked the acorns in room temperature water. Sound acorns sink and empty ones float. I discarded the floating acorns.

Step 2: I shelled the acorns and removed the nut meat. Acorns are true nuts and their shells are fairly easy to crack, and the meat comes right out.

Step 3: I soaked the nuts for roughly 30 minutes until the husks were wet. Afterwards, I drained the water thoroughly. The water is very bitter and full of tannins, so there is no other use for it.

Step 4: I roasted the nuts for about 30 minutes at 300F until the papery husk sloughed off.

Step 5: Once the nuts cooled, I removed the husks by rubbing them off each nut with my fingers.

Step 6: Another step was needed to remove the mouth-puckering tannins from the nut. These tannins cause proteins in your mouth to contract, causing an unpleasant “dry” sensation. This would not be delicious and, in quantity, can be harmful to eat. My research showed many ways to remove tannins. I chose to remove them with cold-water leaching. I first put the acorn nuts in a blender filled with water. I pulsed the mixture which ground up the acorns and made a slurry. I did this to reduce the surface area of the nuts which helped to removed the tannins faster.

Step 7: I poured the slurry into a jelly bag and allowed the liquid to drain, stirring the mixture as it drained. You can see the milky nature of the liquid. This “acorn milk” is very tannic, so I disposed of it.

Step 8: I ran cold water over the nuts in the jelly bag until the water ran clear. I thought this would take a very long time, but it only took 20 minutes. I tasted the pieces to ensure that they lost all of their bitter tannins. They should taste nutty and sweet!

Step 9: I then allowed the nut flour to thoroughly drain and removed it from the jelly bag. I placed it on a baking pan.

Step 10: I roasted the nut flour on a baking pan at 300F, stirring it with a whisk every 15 minutes until it was toasty brown and the aroma was heady. This took about 90 minutes. Afterwards, I cooled the flour before using it in the RORG cake recipe. Leftover flour can be stored either in the freezer or an airtight container.

USING ACORN FLOUR

For the RORG cakes, I used a yellow cake recipe but altered it. The acorn flour provides substance AND oil because nuts are oily. So, I replaced some of the cake flour and some of the oil in the recipe with the acorn flour. The RORG cakes were moist and unusually nutty. Some said they tasted like a mix of hazelnut and sunflower seeds.

There are many Native American recipes that use acorn flour, including acorn cornbread, acorn flapjacks, and acorn “grits.” Any way you use them, they will be unusual and delicious.

For a limited time, you’ll receive a basket of hand-crafted harvest goods from Berries & Flour for your $500 gift to the Red Oak Rain Garden. Click here to make a donation.