Flip through any children's coloring book, and the images depicting autumn will be guaranteed to contain falling leaves, acorns and pumpkins. Acorns are one of the iconic images of fall.
But for most, they're simply objects littering the ground as summer fades into snow. In truth, acorns are a very old ingredient, and were a staple food for many cultures throughout history.
Acorns are a natural fit in recipes such as pancakes, quick breads and cookies. The acorn lace cookies featured here have the added advantage of using a small amount of acorn flour, which means it is an easy recipe for first-time acorn eaters.
So, why has eating acorns fallen out of favor? Acorns are mouth-puckeringly astringent, an effect caused by tannins. Before one can cook with acorns, most of those tannins must be removed with several changes of water, a process known as leaching.
Removing the tannins from acorns can be done by methods known as hot leaching and cold leaching. In hot leaching, larger pieces of acorns are boiled in multiple changes of water until free of tannins. Cold leaching acorns uses cooler water and takes more time. However, the great benefits of cold leaching are that the acorns retain their caramel-like flavor and also a greater amount of starch, which helps the flour to have a more sticky quality when baking.
Collect acorns once they've fallen to the ground. Avoid collecting any that have the cap still attached or have visible bug holes. Further cull out bad acorns from good ones by putting them into a bucket of water. Acorns that float can be discarded.
Place the good acorns onto a baking sheet and roast them gently at 250 F for an hour. This makes the shells less leathery and easier to crack. It also will kill any larvae that might be inside, and it imparts an extra level of toasted flavor to the acorns. Once the acorns have roasted, let them cool overnight.
The next step is to crack and remove the acorn meat from the shells. I believe this task is most enjoyable when many sets of hands join in while sitting in the autumn sun. Use your judgment to decide which acorns to keep. If any look rotten or riddled by bugs, don't use them.
Once you are in possession of all clean acorn meat, you need to grind them. I like to use a grain mill made for processing corn for tortillas. However, a food processor works just fine. You are looking to end up with a coarse meal, much like almond meal.
You are now ready to leach the acorns. Fill a glass jar no more than one-third the way with acorn meal. I tend to leach acorn meal in several gallon jars because I process large quantities. But to end up with the two tablespoons of acorn flour required for this recipe, you won't need any more than one-third of a quart jar of acorn meal. Fill your jar with cool water, stirring gently with a long spoon or chopstick. At first, the water will be cloudy. After a while, the acorns and their starch settle to the bottom, leaving tea-colored water above.
Let the jar sit for several hours at room temperature before carefully decanting the water off the acorn meal, being aware not to disturb the layer of starch on top. Again, fill the jar with fresh water while gently stirring the acorns, and after a few hours decant the tannic water. This process is repeated as many times as it takes to remove the astringent flavor from acorns. At two empties per day, I generally find this takes about a week. The only way to know for sure is to taste the acorns. If you are changing the water twice per day and your home isn't overwhelmingly hot, this can be done at room temperature. If you need to change the water less frequently, you should let the jars of acorns leach in the refrigerator.
Once your acorn meal no longer makes you pucker, pour off about half of the tannic water. Line a strainer with a cotton tea towel, and place it in your kitchen sink. Give the acorns and water a good stir, then pour the contents of the jar into the strainer. Let the water drain for five minutes. Then, gather up the edges of the towel around the leached acorn meal and squeeze out most of the remaining water.
Use your hands or an offset spatula to evenly distribute the wet acorn meal on a dehydrator sheet. Dehydrate the meal at least overnight or until it seems completely dry. Once dehydrated, acorn meal can be stored in your pantry in a jar.
For this recipe, the dehydrated acorn meal is ground into flour using a spice grinder.
You can read a more detailed description of the above process accompanying my recipe for acorn falafel.
Acorn Lace Cookies
Prep time: 15 minutes
Cook time: 30 minutes
Total time: 45 minutes
Yield: 16 cookies
Ingredients
2 tablespoons butter
1 tablespoon heavy cream
¼ cup sugar
zest from half an orange
1 ½ teaspoons flour
2 tablespoons acorn flour
pinch of salt
Directions
1. In a small pan, melt the butter over medium heat.
2. Add the cream, sugar and orange zest. Stir to combine the ingredients, then increase the heat to medium-high, and let it bubble for 2 minutes.
3. Remove the pan from the heat and stir in the flours and salt.
4. Let the mixture stand until it is solid but not completely cool.
5. Roll 1 teaspoon of dough into balls, and place them onto a small sheet of parchment paper.
6. Preheat oven to 375 F, and line a baking sheet with parchment paper.
7. Place 6 of the balls onto the sheet pan, allowing plenty of room for each to spread as they bake. Do not try to cook more than 6 at one time. Bake the cookies for 8 minutes, rotating the pan halfway through cooking. Watch the cookies very carefully over the last two minutes so they don't burn. When fully cooked, the cookies will be a deep caramel color and shiny.
8. Remove the cookies from the oven and let them sit on the sheet pan for at least 2 minutes before handling. Once you can slide a spatula under them without deforming their shape, they can be transferred to a cooling rack. If you are feeling ambitious, it is at this point that the still-flexible cookies can be draped over a small bowl or rolled around a rod so that they dry in that shape.
9. For the two subsequent batches of cookies, baking time may need to be reduced by 30 seconds to 1 minute. Again, watch them carefully to make certain they are not burning. If the acorn lace cookies seem to be burning around the edges before they are fully cooked, reduce the oven temperature by 25 F.