A very knowledgeable gentleman, Doug Huffman from Sierra School of Survival, taught me how to make this while out on the trail one day. While it is in no way similar to drinking coffee, it is very warming on cold days and provides that much needed comfort of home. Acorns are high in fat and protein and so are a welcome addition to a survival diet. Additionally, after drinking the tea you feel like you could hike for hours due to its metabolism increasing properties.
When you are selecting acorns to harvest, you want to get them as green as possible. Only the freshest ones will do. Acorns can go bad from soaking in their own oils in the sun very quickly. Also, you must collect them daily if you plan to win the race against all the other animals that value their nutritional properties as well. You can store your acorns in a five gallon bucket in a cool area, away from any other animals.
Acorns are very high in tannins so they must be properly prepared or you will get sick and it tastes very bitter. Once you have your acorns collected you need a good place to smash them. This can be done with a rock or a hammer. Warning: Don't smash them too hard or you will send everything flying. You want to harvest the fresh greenish meat that is awaiting you inside. Once you have cleaned all your acorns, you want to put the meat in a sock. The finer the sock the better so a panty-hoe works well. You then soak your acorns to leach out the tannins. You can put them in a river for three days but be careful of animals that will want to eat them, including water dwelling animals. You can soak them in a tub of water that you empty and refill three times a day for three days. My friend's personal favorite was to put them in the back of a toilet that is in a shop (not a guest bathroom because the water will get brown). The water in the back of the toilet is clean and every time someone flushes the acorns get fresh water but the water going into the toilet bowl will be brown with the leached tannins.
Once your acorns have been leached it is time to get the acorns ready for tea making. Add some acorns to a skillet and brown them to a caramel color. You must keep stirring constantly. You do not want to burn any of them or they will taste yucky in your tea. Once it's all browned up, grind it up in a coffee grinder. Then return it to the skillet and brown it again. Then put it back in the grinder and grind again. Once more you will put it in the skillet brown it and then return to grinder. You should brown it and grind it a total of three times.
To make the tea itself, use one tablespoon of your acorn mix and put it into hot boiling water. The more water you add the less potent it will be but you can reuse your acorn mix multiple times if you use a tea bag or just keep adding more water to the cup. Every time you add more water let it steep for ten minutes. If you want to really jazz it up add a chunk of caramel candy to the tea. It will make it sweet and super yummy.
Nutritional Note: The gentleman who taught me how to prepare acorn tea told me that acorns contained theophylline. Theophylline's molecular structure is similar to caffine. I definitely feel more energetic after I drink acorn tea but when I tried to find information on the amount of theophylline in acorns I found nothing about it. I did find a study that confirms it's existence in cocoa beans and tea. It's a mystery but here is the nutritional information on acorns that I did find out at nutritiondata.self.com