Acorns are very popular in my wild kitchen, and one of the recipes I make most is acorn and walnut granola. This post covers how to get acorns ready to cook, how to toast them, and how to prepare one of my favorite ways to rewild a granola recipe.
Acorns from oaks (Quercus species) are good food once the tannins are leached out; never eat them raw. Leached, dried and toasted, acorns have a flavour all their own, roasted and nutty, almost like cacao nibs. They can be used in similar ways to other nut flours, go into granola, or be baked into bread.

At a glance
| Plant | Oak acorns (Quercus species), white oak and red oak groups |
| Season | Acorns fall in waves from late summer; I usually stop gathering toward the end of October |
| Where in North America | White oak (Quercus alba), bur oak (Quercus macrocarpa) and northern red oak (Quercus rubra), in parks, yards, streets and woods |
| Where in the UK | English oak (Quercus robur) and sessile oak (Quercus petraea), both white oaks |
| Before you cook | Leach out the tannins; never eat acorns raw |
| Keep leached acorns and flour | Dried, then frozen |
| Flavour when toasted | Distinct: roasted and nutty, almost like cacao nibs |
| In my books | Midwest Foraging, Midwest Medicinal Plants and Urban Foraging |
Can you eat acorns?
Yes, once they are leached. Acorns are high in tannins, and a good leaching takes care of the tannic flavour. I leach mine hot: I chop the shelled nutmeats fine in a blender, simmer them at one part nuts to five parts water, and pour off and replace the water until they taste nutty, not bitter. Hot water draws out the tannins faster than a cold soak, so I can do it on the stovetop over a long weekend. Gathering, shelling and leaching are covered step by step in How to Make Acorn Flour.

Which acorns can you cook with?
Any oak’s acorns, once leached. White oaks have less tannin and give the acorn most foragers prefer, but I’m fairly indifferent: I process white and red oak acorns together. Across North America that means white oak (Quercus alba) and bur oak (Quercus macrocarpa) in the white oak group, and northern red oak (Quercus rubra) in the red oak group. In the UK the native oaks are English oak (Quercus robur) and sessile oak (Quercus petraea), and both are white oaks.
How do you toast acorns?
Toasting the leached nutmeats brings out a flavour all its own, roasted and nutty, almost like cacao nibs. Spread dried, leached nutmeats on a baking tray and toast them in the oven until they smell nutty and turn a shade darker, stirring now and then so they colour evenly.
How do you make acorn granola?
Grind leached, dried acorns into flour first, because whole or chopped dried acorns are hard enough to chip a tooth. Mix rolled oats, the acorn flour, walnuts and pumpkin seeds with cinnamon and a pinch of salt, coat them in warmed maple syrup and oil, and bake low and slow on a tray, stirring every 10 minutes until golden. Stir in dried cranberries once it comes out, and let it cool on the tray, where it crisps up. My full recipe for acorn and walnut granola, with US and metric measures, is in my weekly foraging musings on Substack: Acorn and walnut granola.

What else can you make with acorns?
The leached nutmeats can be used whole. Ground fine, acorn flour can be used in similar ways to other nut flours and added to baking mixes, though its flavour is distinct. Remember that there is no gluten in acorn flour, so plan your baking accordingly; I mix it half and half with wheat flour or a gluten-free blend. The nutmeat can also be made into a nut butter or paste with other foraged flavours like chaga, chestnut and hickory for a tasty spread. My family’s acorn banana bread is in my weekly foraging musings on Substack: My famous acorn bread.

How do you store acorns for cooking?
Fresh acorns have a short shelf life. I process them right away, or store them unshelled in cloth bags in the freezer. Once they’re leached, I dry the nutmeats fully in a warm oven or a dehydrator, then freeze them, and freeze the flour too, to prevent them from going rancid. By the end of the fall I have ten to fifteen pounds (4.5 to 7 kg) of acorn flour in my freezer.

What’s in an acorn?
An acorn is a starchy nut, starchier than a walnut or an almond. USDA figures for dried acorns give about 509 calories per 100 g (3.5 oz), with 54 g of carbohydrate, 31 g of fat and 8 g of protein, and most of the fat is monounsaturated. Those figures are for acorns before leaching. The leaching process not only extracts the tannins from the nut, but also the minerals, as Rodrigues and colleagues found in a 2026 study of three European oaks (Journal of Food Composition and Analysis, vol. 149). Leaching removed about 90 percent of the minerals and much of the fibre and sugars, while the makeup of the fat stayed much the same. I leach mine hot, in a simmering pot, and nobody has measured what is left after leaching at home, hot or cold. I cook acorns for their flavour, which is unlike any other nut. Acorns are a tree nut, so if you have a nut allergy, take care.
| Per 100 g (3.5 oz) | Dried acorns, before leaching (USDA) |
|---|---|
| Energy | 509 kcal |
| Carbohydrate | 54 g |
| Fat | 31 g, mostly monounsaturated |
| Protein | 8 g |
| After leaching | Most minerals and much of the fibre and sugars wash out with the tannins |
Sources: U.S. Department of Agriculture, Agricultural Research Service. FoodData Central: Nuts, acorns, dried (FDC ID 170565). https://fdc.nal.usda.gov/food-details/170565/nutrients Rodrigues, C. V., Maia, M. L., Babo, P. and Pintado, M. (2026). Impact of leaching on the nutritional composition of acorn species. Journal of Food Composition and Analysis, 149, 108788. https://doi.org/10.1016/j.jfca.2025.108788
Is gathering acorns bad for the oaks?
Gathering acorns will not significantly affect the growth of young oaks. Oak wilt is a concern across North America, and habitat loss is an issue for all our large hardwoods, so look after the trees you gather from.
Safety
Be certain of your identification before eating any wild plant. If in doubt, don’t forage it. Never eat acorns raw; leach them first. Acorns are a tree nut, so take care if you have a nut allergy. Gather away from roads, rail lines and lawns treated with herbicide. Some city and state parks do not allow foraging, so check the rules, and ask before you gather on land that is not yours. As with introducing any new food or herb into your diet, do so with care to rule out any adverse reaction.
Questions readers ask
No. Fresh acorns are bitter with tannins and must be leached in changes of water until they taste nutty. Only cook with acorns that have been fully leached.
Leached and toasted, acorns have a flavour all their own, roasted and nutty, almost like cacao nibs. The flavour is distinct, not a stand-in for another nut.
Yes. Grind leached, dried acorns into flour and bake it with the oats and nuts; whole or chopped dried acorns are hard enough to chip a tooth. My acorn and walnut granola recipe is in my weekly foraging musings on Substack.
Dry the nutmeats fully in a warm oven or a dehydrator, then freeze them, and freeze the flour too, to prevent them from going rancid.
About 509 calories per 100 g (3.5 oz) of dried acorns before leaching, by USDA figures, most of it from starch and fat. Leaching removes most of the minerals along with the tannins, as Rodrigues and colleagues found in 2026. Sources: U.S. Department of Agriculture, Agricultural Research Service. FoodData Central: Nuts, acorns, dried (FDC ID 170565). https://fdc.nal.usda.gov/food-details/170565/nutrients Rodrigues, C. V., Maia, M. L., Babo, P. and Pintado, M. (2026). Impact of leaching on the nutritional composition of acorn species. Journal of Food Composition and Analysis, 149, 108788. https://doi.org/10.1016/j.jfca.2025.108788
No. Mix it with wheat flour or a gluten-free blend when you bake, and plan the recipe for a flour that will not bind on its own.
Acorns in my books
I write about oaks as food and medicine in all three of my books, Midwest Foraging, Midwest Medicinal Plants and Urban Foraging (Timber Press).
Recipes are part of my weekly foraging musings on Substack. Subscribe and follow to get all my tips.































































































