All About Acorns

Here in New Hampshire at the Mt. Kearsarge Indian Museum, the acorns in the Medicine Woods are under a foot of snow.  But earlier in the fall the sound of acorns dropping from the oak trees was almost continuous, and the forest floor was carpeted with hundred of acorns.  Anyone venturing into the Medicine Woods in October would have been well advised to wear a hard hat.


In late September and early October the animals of the Woods were busy gathering these protein-rich nuts and stashing them away for use later in the winter.  These creatures know that acorns are a valuable source of important nutrients.  Across Turtle Island native people also recognized this fact, and acorns were an important staple of their diet.  Now research shows that acorns contain many healthful compounds, especially antioxidants. Acorns are an important source of phytochemicals, chemical substances found in plants that can help prevent diseases and cell damage.  Regular consumption of foods rich in phytochemicals is associated with reduced risks of chronic diseases such as cancer, cardiovascular disease, stroke, Alzheimer's disease, cataract and age-related functional decline.  (See "Health Benefits of Phytochemicals in Functional Foods"  Cornell University, 2002.)  In addition to their phytochemical content, acorns are a source of protein (about 8 percent) and fats (37 percent.)  They are also high in calcium and other minerals.

The first Native Americans to add acorns to their diet were not aware that the nuts they were gathering contained antioxidants and phytochemicals.  However, the lives of native people were closely linked to the earth and its inhabitants, which led them to develop a great body of knowledge of the natural world.  Thousands of years of experience taught native people which foods provided the best nourishment and energy that their active lives required.

At the Mt. Kearsarge Indian Museum we have learned that the average native family in the Northeast Woodlands would need approximately 600 pounds of acorns to provide enough food for the long, cold winter months.  Given that the average acorn weighs 0.01 lbs, 600 lbs. of acorns amounts to approximately 60,000 acorns!

Before the nutmeat of acorns can be eaten, the nuts must be treated to remove tannic acid, which gives them a bitter taste.  Removing the tannins greatly improves the flavor of acorns, but there are more important reasons to flush tannins from acorns. Tannic acid can interfere with the body’s ability to metabolize protein.  Eating untreated acorns could ultimately result in starvation, even in an individual eating an otherwise healthy diet.

Animals in the wild have developed several ways to reduce the amount of tannic acid in the acorns they eat.  Animals that cache acorns, like jays and squirrels, may wait to eat them until enough groundwater has percolated through them to leach out the tannins.  Other animals buffer the effect of tannic acid by eating other foods in combination with the acorns. Some insects, birds, and mammals can metabolize tannins with few of the ill effects that could cause kidney damage in humans.

How do Native Americans remove the tannins from acorns?  After the acorns have been harvested they are spread out on a blanket and set out in a dry, sunny place for several days. The sunlight creates enough heat inside the acorn to kill any insect eggs or larvae that might be living there.  It also prevents the acorns from becoming moldy before they are shelled.

When the acorns are thoroughly dry they are cracked open and the nutmeat is picked from the shells.  Now the tannins can be removed.  Some people preferred to place the nutmeat in a basket set in clean, fast-flowing water.  After a day or two the tannic acid would be flushed away.  Others prefer to remove the tannins by boiling the nutmeat in a large pot.  When the water has turned brown it is poured off and replaced with fresh hot water.  This process is repeated several times until the water remains clear.  This job generally takes two or three hours.  When the boiling process has been completed, the acorns will have turned dark brown and will no longer taste bitter.  Eaten from the pot, the acorns have a flavor similar to that of boiled chestnuts.

Now the nutmeats must be dried again.  When they have become dry they can be roasted or chopped and eaten.  However, it is more common to grind the dry nutmeats into fine flour.  This flour can be used to make acorn bread.

Another method is to grind the nutmeat while it is still wet until it has become a moist paste.  This acorn paste is ready to be added to the acorn bread recipe.

Acorn meal is naturally sweet, which adds flavor to the bread.  Bread made entirely of acorn flour is very dense.  Some cooks added cattail flour, which helped keep the bread from crumbling.  A piece of acorn bread provided a nourishing meal for someone on a long trip or a hunting expedition.

The fact that the native people of the Northeast Woodlands were accomplished foresters is often overlooked.  They adopted effective and sophisticated ways to manage their acorn crops.  Lighting ground fires increased the production of acorns and made them easier to collect.  The fires killed the larvae of the acorn moths and acorn weevils, which could consume more than 95% of an oak tree’s crop.

The fires freed nutrients bound in dead leaves and other plant debris and released them into the soil.  The fire also reduced bushy growth on the forest floor, which made it acorn gathering easier.

Most North American oak trees can tolerate light fires, especially when yearly burning has consumed dead wood and other flammable materials that would otherwise accumulate around the trunks of the trees. Consistent burning removed other less fire tolerant trees from the area and created more space in which new oak trees could grow.

Oak trees bear more acorns when other oak trees do not crowd them.  The controlled burns tended to remove oak saplings and diseased trees, opening the forest canopy to allow more sunlight and water to reach the healthy trees.  The result was an open oak savanna, with trees ideally spaced to maximize acorn production.

There are many recipes for acorn bread available online or in books.  Here are a few that look interesting:

•  Acorns and Acorn Bread by Dan Fisher  http://www.jackmtn.com/acornbread.html
• Vintage and Native American Acorn Bread  http://www.grouprecipes.com/21418/vintage-and-native-american-acorn-bread.html
• Recipe for Acorn Bread from the California State Parks Online Resource for Students and Teachers  http://ports.parks.ca.gov/?page_id=25519

Bon appetit!