Acorns are quite nutritious. For example, the nutritional breakdown of acorns from the white oak is 50.4%carbohydrates, 34.7% water, 4.7% fat, 4.4.% protein, 4.2% fiber, 1.6% ash. A pound of shelled acorns provides 1,265calories, and roughly 100 grams of oil. During World War II Japanese school children collected over one million tons of acorns to help feed the nation as rice and flour supplies dwindled.
Oaks are very common growing over most of the US. In my area, the Native Americans depended heavily on them for a food source. I have been experimenting with acorns for several years. There is a definite learning curve; you need to learn to cook with them now, and not when you are hungry.
This year I collected acorns from a tree near my home. These were a good mild tasting acorn not bitter. Acorns differ in taste depending on the type of oak tree. Some types of acorns are bitterer than others. This is because they contain more tannic acid. Many Native Americans preferred bitter acorns to sweet ones because they stored better.
One thing I have learned is that green or fresh acorns are much harder to shell than ones which have had time to dry out. The shells on the fresh ones are more pliable and don’t crack easily. I would recommend drying fresh acorns either in the sun or with a dehydrator. A couple of days in the sun makes a lot of difference.
Prior to cracking, your acorns dump them into water and separate the ones that float. Throw the floaters away, they are rotten inside. Next look through the acorns and throw away any with wormholes. Now crack the acorns. An easy way is to put the nuts on the floor between two towels and hit them with a hammer. The nuts now need to be ground into course flour. This year I cheated and used a blender. The Native Americans ground the acorns between rocks. In the past, I have mashed them with a piece of metal. I intend to try a hand grinder in the future.
I then placed the course flour in a colander lined with a coffee filter and ran water through it. The flour came out sweet tasting. I then dried part of the flour and stored it in paper sacks. More on how to use the flour later.