The incredible edible acorn. The Oak tree is one of the most wide spread trees in the world and the acorn was a staple of the human diet going back literally forever (human forever at least). It is seldom used anymore because other grains and nuts are easier to make into flours on a large scale. I think it’s a worthwhile project to collect acorns and process them into flour which it can be stored long term. The flour is sweet and earthy, a really interesting flavor. Acorns are also full of minerals, much more than other cereal grains. The Oregon White Oak has a large range that begins in British Columbia and runs through the Willamette valley into California. Several other Oak varieties are widespread across North America and acorns can be collected from these trees and eaten as well. The White Oak overall yields a superior acorn however which is large and has sweet properties. Although all acorns have bitter tannins, the White Oak has far less and is therefore easier to process. The White Oak is very easy to identify as it has rounded margins on its leaves and elongated acorns whereas other oaks such as the Black Oak have straight margins on the leaves and rounded acorns. Oak trees tend to have huge crops of acorns some years and almost none other years, so when when life gives you acorns, make… acorn flour!
Acorn flour is a rare food item and although we are all surrounded by acorns each fall, chances are you have never tasted it. Euell Gibbons, the modern guru of foraging calls acorns “ancient food of man” and “staff of life” for humans before cereal grains made their appearance in our diet. These quotes alone peeked my interest in searching out and utilizing this food. Making acorn flour (probably the best use of the acorn) is not quick to make but relatively easy and well worthwhile especially if you make a large batch when acorns are abundant. You can then use the flour several times throughout the fall and winter. When acorns are ready to crack they will be brown, not rather than green which indicates they have yet to ripen. If they nutmeat is difficult to remove it means they are still not dry enough to process so let them rest longer. The best way to dry them is to lay them in a single layer, once dried they can actually be stored for a year or more.
any mass of White Oak acorns
A: Begin by cracking each acorn and removing the fruit from each as you would any other nut. You can use a hammer (works) or nutcracker (works better). This is really the only time consuming step in this process.
Once you have all the fruit harvested, add to a blender and fill with enough cold water to cover by an inch or two. Puree as much as you can, getting it as fine as your blender allows.
B: Pour into a canning jar and store in a cool place preferably below room temperature as this will keep from spoiling.
C: The next day the water will have floated to the top (with the bitter tannins). Just carefully pour only the water off and then add more cold water. Shake jar vigorously and repeat the following day. It usually takes 3 days (times) to finish the process. You can do this once a day or twice, morning and evening which tends to speed up the process. After the 3rd day taste the flour mush. It should no longer be just slightly bitter but smell wonderful. If it seems a little too bitter though, continue to leach out the tannins for up to 2 more days.
D: When ready line a strainer with cheese cloth and fill with your wet acorn flour. Squeeze out most of the water and then leave it to slowly drain for about a day or even overnight. Spread flour on a baking sheet and put the oven rack in the middle-high position at 200 degrees for about an hour or two until it dries. Check and mix it up a few times by basically sifting it up with a fork.
E: Next, blend dry flour in blender, or better yet, a coffee grinder. The finer you can get it the better it will be. Sometimes if it remains course it will be more like a meal than flour which is okay too, but is quite as effective as a flour substitute.
So now what do I do with my acorn flour? This flour is not a good substitute for recipes that call for solely white wheat flour or use yeast or other methods to rise, it is however a terrific addition to baked goods and especially desserts. Muffins, pie crusts, cookies are all good ways to use acorn flour. A recipe for acorn flour muffins follows.
Holiday Cranberry-Pear & Acorn Muffins
1 pear, unripe-barely ripe
2 large handfuls fresh cranberries
1 cup acorn flour recipe follows (substitute chestnut, hazelnut, or almond flour)
1 tsp Bob’s Red Mill aluminum free baking soda
1 1/2 tsp cinnamon, divided
4 tbsp real maple syrup
1/4 cup melted butter
Other nut flours do work well for this recipe and honestly are easier to find, such as almond, hazelnut and chestnut. Each flour changes the flavor and consistency a little but I have tried them and they all work as does mixing two of the flours together. If you can’t find these flours the nuts can all be made into flour by simply grinding them in a coffee or spice grinder.
Preheat oven to 350. Slice each cranberry in half and chop pears into slices, then dice pear into smaller pieces leaving the skin on. Sprinkle 1/2 tsp cinnamon on pears and cranberries and tumble to mix with hands.
In a bowl add flour, baking soda, tsp cinnamon, and salt and whisk. In a 2nd bowl add eggs, syrup, melted butter and whisk. Add dry mix to wet mix and continue to stir to get good batter consistency, add cranberries. Either use muffin tin liners or generously grease a muffin tin with room temperature butter or cooking spray (butter is hard to beat though).
Next fill each tin about 1/3 full with the mix. Divide the pear pieces and place on top of each muffin. gently push them down so they sink in. Bake for 15-20 minutes, a quick finger poke will let you know when they are ready, acorn flour & hazelnut flour about 15 min, almond & chestnut flour 20 min.
Let cool for a few minutes but not too long, muffins are meant to be eaten warm.
Recipe makes 8-10 muffins.