Oak (Quercus species)

Oak tree acorns from various anglesOak trees have alternate leaves and edible acorn fruits. The leaves of the Oak may have serrated edges or may have smooth edges.  The flowers are catkins produced in the Spring season.  The fruit is a nut called an acorn.  It is held in a cup-like structure with each acorn containing a single seed.

There are two main groups of oaks: red and white. The red oak group has spirally arranged eaves with bristles and smooth bark in the upper part of the tree. Red oak acorns take 2 years to mature. The white oak group has spirally arranged leaves without bristles and a rough bark in the upper portion of the tree. White oak acorns mature in 1 year.

An Oak tree in the wildWhere to Find: Oak trees are found in many habitats throughout North America, Central America, and parts of Europe and Asia.

Edible Parts: All parts are edible, but often contain large quantities of bitter substances. White oak acorns usually have a better flavor than red oak acorns. Gather and shell the acorns. Soak red oak acorns in water for 1 to 2 days to remove the bitter substance. You can speed up this process by putting wood ashes in the water in which you soak the acorns. Boiling the acorns also removes the bitter tannin (the nut will have a sweet, mild taste).  Boil the acorns or grind them into flour and use the flour for baking. You can use acorns that you baked until very dark as a coffee substitute.

Oak tree leaves and acornsNote: Tannic acid gives the acorns their bitter taste. Eating an excessive amount of acorns high in tannic acid can lead to kidney failure. Before eating acorns, leach out this chemical by soaking in water.  You can also remove the tannin by crushing the acorns and sieving them by placing the shelled acorns in a filter material (e.g. cloth) and pouring water over them for five minutes.  A white creamy substance will leach out (this is the tannin).  When the water becomes clear then all tannin has been removed.

Acorns are a dense food chock full of complex carbohydrates, vitamins and minerals.

Other Uses: Given its superb density, strength, and hardness, Oak wood is excellent for building or burning. Small oaks can be split and cut into long thin strips (3 to 6 millimeters [1/8 to 1/4 inch] thick and 1.2 centimeters [1/3 inch] wide) used to weave mats, baskets, or frameworks for packs, sleds, furniture, etc. Oak bark soaked in water produces a tanning solution used to preserve leather.

Green acorns on an Oak tree (only ripe acorns should be eaten)

Acorns on a Oak tree

Oak tree leaves

Oak tree flowers or catkins

Close-up of Oak tree catkins

Color drawing of a Oak tree and its components

Color drawing of a Oak tree and its components

Drawing of a Oak tree and its components