Processing Acorns

Acorns Part One;
Processing

(See full blog post with better pictures here.)




Acorns are the seeds of the oak tree and they can be found all around the world. During most of fall the ground will be littered with ripe acorns (don't eat the immature green ones) anywhere oaks are found. This makes them and abundant food source that with minimal work can be processed and stored to last you through the winter.



Black Oak Leaf



Red Oak Leaf



White Oak Leaf



Oak Tree
Acorns contain tannic acid that must be removed before consumption. There are various species of oak each with different amounts of tannic acid. Your white oaks have the least amount of tannic acid, while your red and black oaks have the most. A good general rule to estimate the amount of tannins is by looking at how large the cap is in proportion to the rest of the acorn. The larger the cap, the more tannic acid the acorn will generally have. The most common way to removing the tannins is a process called leaching.



Once you've collected your acorns, you'll need to remove any of the bad or infested acorns. The easiest way to do this is to remove the caps and put them in a container of water and remove any that float. You'll want to stir them around to make sure the healthy acorns aren't stacked on top of a few of the bad ones and let them float to the surface. The good acorns will stay at the bottom of the container. Once you have sorted out the bad acorns, agitate the acorns in a couple changes of water to remove any dirt or bugs that might be on the acorns. Once the acorns are clean you may want to save some of the whole acorns for later. Once dried and properly stored they can last for months in this form. The ones that you want to use at the time should be shelled and the acorn meat collected. They are now ready for the process of leaching out the tannins.
Leaching can be done in one of two ways with acorns; cold leaching and hot leaching. Cold leaching is usually the preferred method because you won't cook the starches, so your acorn flour will not fall apart as easily and the cooked starches won't bind with the tannic acid that will leave a bitter taste or in severe cases will leave them unusable. Cold leaching however takes far longer. Alternatively hot leaching takes far less time though you will cook your starches, so it won't hold it's form well by itself and you won't be able to use the acorn starch as a binder or thickener. For cold leaching, put your shelled acorns in a container of water. Lightly shake the container several times a day and change the water everyday until the water comes out clear. This process can take several days and with red or black oak possibly several weeks. Once the water comes out clear the acorn meat is dried and is ready for use. For hot leaching you'll need to prepare 2 pots of boiling water. Once both pots are boiling add your acorn meat to one of them and wait for the water to a dark tea looking color. Once that happens drain the water out (this tannic acid tea can be used to 'tan' leather). Add the acorn meat to the 2nd pot of boiling water then fill the first pot with fresh water and set it to boil again. Repeat this process until the water stays clear. Always make sure the water is boiling and don't let the acorn meat cool down the entire process. Once the water stays clear the acorn meat is dried and is ready to use. Native Americans would put the acorn meat in a knit sack or basket and set it in stream with clean moving water until the water stays clear when inspected.
Now that you have leached acorn meat there is a lot you can do with it. Enough to where I'll dedicate an entire article to the subject next time.