Delicious, Erratic Acorns
Our back deck at Winding Pathways is an outstanding vantage point for watching butterflies, birds, and even our evening aerialist bats. The deck is perched over a deep, cool ravine with a stately black oak hovering above. That can be a problem.
In most autumns our black oak cascades acorns down to the ground and our deck. Removing them takes aggressive sweeping. Despite the hassle we love acorns.
Acorns are, of course, the seeds of oak trees. Hundreds of oak species live across much of the northern hemisphere. They can be a little tricky to identify since oaks sometimes hybridize and look like a blend of two or more species. Many people use leaf shape to identify trees, but oaks may throw a curve. Often leaves, called sun leaves, up on the top of an individual tree are smaller and may have a somewhat different shape than those down lower on the same tree. It can be confusing.
There are two general oak types, the white and red oak groups. White oak type trees include species commonly called white, swamp white bur (sometimes spelled burr), chinkapin also spelled chinquapin, and chestnut oaks. Their leaves have rounded lobes and they produce large acorns with low acid content. Red oak type trees include species commonly called red, black, and pin oaks. Their leaves have pointed lobes and their acorns are usually small and laden with bitter acid.
Acorns from the black Oak are small and bitter.
Oaks have different shaped leaves
Century Oak Tree
Oak leaves turn russet in autumn.
Acorns are nature’s gift to many wildlife species and people. Few seeds are as abundant, large, and nutritious as acorns. Squirrels, chipmunks, muskrats, woodchucks, deer, bears, blue jays, wild turkeys, and a host of other animals gorge on them. The calorie-rich nuts help wildlife put on fat that helps them survive the coming winter.
But, there’s a problem. Oaks are erratic acorn producers. As a general rule, the white oak types only create a heavy crop every few years. Red oak type trees are more reliable but still sometimes skip a year of seed production. Sometimes few oaks in a vast area will produce acorns while an individual tree here and there will be loaded. Find a heavy acorn bearer in a scare year and you’ll have the company of many animals feeding on the nutritious nuts. Part of the reason for erratic crops stems from pollination. Oaks are wind-pollinated and a long spell of rain when they bloom in the spring can dampen pollination and eliminate a crop that autumn.
Acorns set up in the spring
The white meat of an acorn.
Two kids check out the acorns on a branch
Iowa has many types of oaks
Acorns are a delicious human food that was relished by native people across the globe. To learn more about acorns and how to process them into food check out the Winding Pathways blog of August 2014 called Delicious Acorns.
Strutting his stuff
As we enjoy Thanksgiving dinner we pay homage to the great gift the Americas gave the world.
Beef, pork, lamb, and chicken all come from animals with Old World origins. Shortly after Europeans discovered North and South America, Australia, New Zealand, and other new worlds they introduced these familiar and useful farm animals. Before Columbus made landfall, Native Americans knew nothing about these exotic animals. But, they knew turkeys.
Of all common meat animals eaten today only turkeys came from the New World. Before Columbus, wild turkeys abounded across much of North America. Their domestic cousins were tended by some tribes. Treated with great care, the domesticated turkeys were an important source of clothing, tools and food. Among some uses of the tribes of the Four Corners of the United States, turkeys provided feathers for coats, eggs for eating and reproduction, and bones for tools. Evidence exists that the Native Americans cross bred for certain valued characteristics. Europeans quickly developed a taste for turkey and brought them eastward across the Atlantic where they became a common European food.
Our Thanksgiving dinner consists of turkey, potatoes, and winter squash, all Native American foods. Sometimes we add acorn muffins and capstone the meal with a long time family recipe for pumpkin pie, made from a plant that also originated here.
Every fall zillions of acorns cascade down into lawns, tumble roll off roofs, and pile up in American driveways. Raking them up is a dreaded autumn chore. Anyone who collects and disposes of acorns is tossing away delicious food.
Too many people believe these big oak nuts are toxic, perhaps because they are bitter when eaten raw. For deer, woodchucks, squirrels blue jays and a host of other wild creatures, acorns are a bonanza of nutritious food so important that a heavy acorn crop means a winter of good health while a sparse one spells starvation.
Native Americans enthusiastically collected, processed, stored and ate acorns. And they are a common food in some European cultures. A great acorn benefit in the days before refrigeration was the ability to store them indefinitely, providing food if crops failed or game was scarce. Far too many modern people don’t realize that acorns are delicious if properly prepared.
Dozens of oak species live around the world. In North America much of the eastern hardwood forest is dominated by oaks with several scattered scrubby species in the southwest and many larger ones near the Pacific coast. Even on the Great Plains and in the Rocky Mountains, where native oaks either don’t occur naturally or are uncommon, they have been planted in nearly every town and city.
Although there are many oak species all fall within one of two categories:
White Oak Group: The leaves of these oaks have rounded lobes and generally the trees produce an abundant acorn crop irregularly. Often a few falls go by with a sparse crop nuts. Then during a banner year, millions of acorns carpet a forest floor. Almost every year there will be a tree or two here and there with a heavy crop while others nearby are barren. Common white oak group species are the bur, white, and chestnut oaks. Acorns in this group have the lowest tannin content, are usually large and require the least processing. If white oaks live in your area these are the acorns to gather.
Black (or Red) Oak Group: These trees have leaves with lobes that end in points. The acorns are usually smaller than those in the white oak group but normally trees in this group produce a more reliable crop. Typical species are pin, black and red oaks.
Nearly all oaks produce acorns that can be processed for food, but because those in the white oak group produce the largest nuts with lowest tannin content, we exclusively process acorns gleaned from under white and bur oak trees. We leave the black oak group acorns for the squirrels.
Tip: When you’ve found a prolific oak just starting to drop its nuts carefully slice an acorn or two in half with a paring or pocket knife and use the point of the knife to pry the kernel out of its husk. Taste it. If it’s only modestly bitter you’ve found great acorns. If it’s very bitter seek out another tree. Although white and bur oaks usually have the sweetest acorns the tannin content varies from tree to tree, so gathering the sweetest acorns reduces later work removing this bitter substance. A white or bur oak tree producing sweet acorns may be growing next to a tree of the same species with bitter kernels. Gather the sweet ones.
HOW TO PROCESS ACORNS INTO DELICIOUS FOOD
Making delicious acorn muffins with school children.
Here is how we convert acorns into delicious food:
• Collect acorns as soon as they fall from the tree. Normally oaks begin dropping nuts in late August. September is the prime gathering month. Usually the easiest way to gather a bunch of acorns is to find a prolific white or bur oak growing over a parking lot or driveway. It’s easier sweeping up a few gallons of acorns from pavement than picking them out of the forest floor or lawn. Various insects realize that acorns are good food and quickly bore into fallen nuts. So, beat the squirrels and bugs to the acorns, pick a few gallons and bring them home. Collect only perfect acorns lacking cracks, sprouts or holes.
• Put newly collected acorns in large zip lock bags and freeze them. Freezing kills insects that may be hiding in the acorns and prevents sprouting and mold. Processing acorns is fairly tedious and time consuming. We are usually busy during acorn season and have more processing time when winter hits. So, we store our acorns in the freezer until later. Processing acorns while sitting next to a cozy January woodstove and listening to music is a pleasant winter activity. But, if you want to immediately process acorns after collecting them freezing is optional.
• Put a few gallons of fresh or frozen acorns in a large pot, like a canning pot, nearly fill it with water, and boil for 15 or 20 minutes. Boiling does two things. It softens the husks, making for easier shelling and it removes some tannin. As tannin leaches out of the nuts the water will darken. Let the boiled acorns cool down and drain them. Collect your tools. You’ll need a sharp paring knife, a cutting board, two pots and a good light source.
• Remove the kernels by cutting each acorn in half lengthwise. It should be easy to cut through the water softened husk. Use the point of the knife to pop the kernels into one bowl and the husks in the other. We compost husks They also make good mulch.
• Pour the kernels into a large pot of boiling water and slowly boil them for about ten minutes. As tannins leach out of the nuts the water will darken. While the nuts are boiling bring another pot of water to a boil. Drain the nuts from the first pot and put the kernels into the second pot of clean boiling water. If your acorns were sweet only two or three boilings will remove the tannin. When boiling water darkens only slightly you know you’ve leached out most of the tannin and there will be little bitterness left. Red or pin oak acorns could take five or six boilings to remove tannin.
• Once the tannin is gone thoroughly drain the acorns in a large colander.
• Spread the drained water-softened acorn kernels on a cookie sheet one layer deep. Dry them in an oven on low heat, stirring occasionally. The object is to dry them, not cook them. This part takes a couple of hours. When dry, the kernels will be rock hard.
Once they are completely dry, hard and cooled the acorns can either be placed in airtight jars or other storage containers or immediately ground into flour. Dried acorns will keep for years and unground kernels can be added to stews much like you might add dried beans. This is how Native Americans commonly used them.
• Place the hard dry kernels in a heavy duty blender or hand or electric mill designed for grinding grain. Grind them to the texture of fine flour. Store in an airtight container. Sift the flour to separate out harder kernels. These you can store separately and add to soups where they soften and add a rich earthy flavor to the broth.
We use acorn kernels in soups and the flour in recipes such as Boston Steamed Brown Bread, cookies and muffins. Here are two of our favorite acorn recipes:
Acorn Cookies from the Kitchen of Yvonne Fellows
½ Cup cooking oil ½ tsp. almond extract
½ Cup honey ¼ Cup acorn flour
2 beaten eggs 1 ¾ Cup regular flour (if whole wheat increase the liquid)
Pre-heat oven to 375 degrees. Blend oil and honey. Beat eggs into the mix. Add almond extract then the wheat and acorn flours. Batter should be cookie dough consistency so add more flour if needed. Drop by spoons full onto greased baking sheet. Bake 15 minutes at 375 degrees.
Acorn Muffins adapted from a recipe by Yvonne Fellows
One beaten egg ¼ Cup sugar
One Cup milk 1 ¾ Cups flour
(mix of whole wheat and white or pastry)
2 TBSP vegetable oil ¼ Cup Acorn sifted flour
½ Cup molasses or honey
(I use a combination) 2 tsp baking powder
1tsp vanilla ½ baking soda
Pre-heat oven to 375 degrees. Grease muffin tins or use baking cups. Mix wet and dry ingredients in separate bowls. Blend wet and dry ingredients together until just moist. Some small lumps are OK. Fill muffin tins or baking cups 2/3 full. Bake at 375 degrees for 20 – 25 minutes. Tops of muffins should spring back when done. To prevent dryness, avoid over baking. Serve warm with honey and butter.
We are lucky to have four species of oak trees on our property. Huge white oaks hug the north end with a few red oaks scattered between them. Two medium sized black oaks live close to the house and a young bur oak is just beginning to cast shade south of the house.
Millions of other homeowners are also fortunate to have oaks shading their property. They are one of the most widespread trees, and are beautiful, sturdy, valued by wildlife and long lived. A white oak could shade the ground and feed squirrels for up to 400 years. Some species, like red oaks, grow relatively quickly and tolerate moderate shade while most other oaks, like our bur, need full sun and grow slowly.
About 600 oak species are found naturally across the northern hemisphere. Approximately 90 species live in the United States. China boasts around 100 species, and Mexico is probably the world leader in oak diversity with at least 160 species. They have been widely planted in temperate regions including many places where they don’t occur naturally.
Oaks are members of the beech family with the genus name Quercus. It’s rather easy to distinguish an oak tree, but determining just what oak species a tree belongs to can be tricky. Many oaks hybridize with similar oak species and a tree may have characteristics of each parent. Sometimes the shape of an oak leaf near the top of a tree may be shaped differently from a counterpart lower down.
Non-showy oaks flower in mid spring about the time leaves appear. Male blooms are slim, drooping and green or tan in color. Each female flower is a solitary spike. People allergic to the wind borne pollen generally suffer in the spring.
Throughout history oak wood has been readily used by people. Even wine corks are made from the bark of Portuguese oaks. Oak was widely used in the construction of sailing ships. It’s said that the oak sides of the USS Constitution were so tough that British cannonballs bounced back. That’s where the nickname Old Ironsides came from! Oak is the traditional wood for liquor aging barrels but today it is most commonly used for hardwood flooring and furniture. Few woods produce more fireplace heat than oak.
Squirrels are just one of the wildlife species that love acorns. Among the host of other wild animals that relish acorns are deer, bears, woodchucks, wild turkeys and blue jays. However, oak leaves or acorns can be toxic to cows that eat too many. Tannin is the bitter element in oaks and acorns and long ago humans learned how to remove it to create delicious food. Each fall we look forward to harvesting acorns. Few foods are as delicious as maple syrup on warm acorn muffins.
Subscribe to Winding Pathways to learn how to process acorns into food.
For further Information
One of the most fascinating tree books ever written was published back in 1948. It is a two volume set by David Culross Perry. One volume covers trees of eastern North America while its counterpart describes western species. If you spot it for sale at a garage or used book sale snap it up.
Websites, apps and books abound that help identify and learn about trees. Our favorite websites are from the National Arbor Day Foundation at and the US Forest Service. Our favorite tree identification book is the Sibley Guide to Trees.