As a keen forager, I am always on the lookout for any new potential forgeable resources to make use of. Several years ago, I couldn’t help noticing the huge amount of acorns that were scattered across the forest floor and remembering my father telling me that they were not to be eaten as they would give me a bad stomach. Now a keen forager myself, the usual question popped into my thoughts ; “Will they make me sick, and if so, WHY? Can I process them in any way to make them usable?”
This started what I can only describe as a bit of a obsession for me and now I feel that I have a sound basis of information collected from various positive results and from utter fails that I would like to share my understanding of one of my favourite foraged resources .
Basically we have oaks which fit into two main groups in the United Kingdom and these are determined by how they offer acorns, this is either every year or every other year. White oaks. (Yearly fruiting trees ) and Red oaks ( Bi-Annual harvests ) each group have their uses and are quite different .
One of the first things you need to learn is correct identification; as is the case with any foraging. This is the basis for all of your best results.
Then you need to find your favourite tree and these are not the easiest to find; in fact there are studies showing that native Americans went to war over their oaks once a good tree was found .
Your tree will be determined by several points that you need to take into account, which include its yield, its accessibility, it’s age, it’s impact upon the surrounding environment and then the important aspect of does it give you the taste that you require .
As regards to the harvesting of acorns, you should try to collect strait from the tree and avoid picking from the floor as you don’t have any idea how long they have been on the ground absorbing moisture and are quite often affected by insects such as the acorn grub. That said, I do however collect corns from the floor after a good storm and it’s quite important to discard any tainted corns before you put any effort into their processing.
This can be done by simply putting in water just before you are about to de-shell them. Any that float are likely to contain a grub or no fruit at all.
I make three different products from acorns and hold them in high value within my larder
Flour , oil and coffee .
As I have previously said, each tree group produce corns which are better suited to each of the products mentioned.
Flour gets best results from yearly fruiting trees
Oils from Bi-Annual fruiting trees
Coffee is best from a 60-40 mix of yearly and Bi-Annual
Now you might be reading this and thinking that this involves a lot of work for a small return and goes against any survival type food: but this is a foraging as a lifestyle. This little fruit has massive positive attributes not only is it nutritious but also medicinal and in my opinion they are high enough in both to apply the amount of energy needed to produce the end result.
I am also aware that it is this amount of effort that prompted an agricultural need for a product which could viably service the need for flour bringing on the need for wheat.
Acorns have great positive effects on blood pressure and are source of carbohydrates, protein, 6 vitamins, 8 minerals, and 18 amino acids, and they are lower in fat than most other nuts.
I am going to share with you my preferred methods of achieving my three products. I am aware there are other ways of achieving the same results and I have tried most of them, but I also believe in continuous experimentation to refine my methods and my efforts so far have led me to the following results.
Within any method of making an edible product from acorns there is one common process due to the tannic acid (commonly known as tannin) within the corns. In Fact, I’m quite sure that if the corns did not contain tannin that we would be using them in our everyday lives.
Tannin is the chemical that is found within acorns that produces the very bitter taste. This needs to be removed to a level which the corns are not astringent ,this is achieved by a process called leaching as the acid is water soluble.
There are quite a few ways to leach the tannin from the corns and I use different methods depending on the product I’m trying to make .
The different methods come into two groups ,boiling or flushing.
When making flour I use cold flushing rather than the boiling as the boiling binds the tannin to the protein and you retain the bitter tastes. It also cooks the starch making the flour of low quality.
This Is done by first removing the shell of the corn which can be done with a knife or simply by crushing and sorting through the matter ( i tend to shell with a knife ) .
When ready to be leached if you have access to running water ( please use common sense when deciding if the water course is suitable to use. If you use a stream or natural source utilise the same methods of safe water collection).
Place the corns into a bag or net which is able to let the water pass through but retain the fruit, and weigh down with some rocks , then secure the bag as not to lose it and place in flowing water for two – three days.
On day 2 you can try tasting the acorn, it should taste sweet. If not, leave them another day and try again until you’re happy with them and they are ready to dry.
If you don’t have running water simply crush the corns into small pieces and place them in a sealed container full of water and change it everyday until it runs clear (missing a single day will spoil the mix).
When it comes to drying for flour making, I tend to air-dry or sun-dry them. The sun is the prefered method and tends to take around 4-5 days. They must be stored dry overnight to prevent re-absorption of moisture from the cool night air and don’t leave them unprotected during the day or every passing bird will stop by for lunch!
The air drying method takes much longer and requires a lot of diligence, continuously checking for mould and insect infestation and depending on the weather can take 4-5 weeks to dry, this gives a lot of time for problems to occur .
Once you are happy that they are suitably dry then you are ready to grind them. This can be done with a Mortar and Pestle or a coffee grinder.
I then leave it to dry for another day to further dry the grounds.
The next part of the process is the storage. The modern air tight container is used by most people but be aware that the life span is 3-4 months. If you want to keep it longer a brown paper bag will increase this by a further 8-12 weeks ,the only other method I’ve used is a breathable bag such as hessian, this gives the flour a crust on the inside of the bag which in fact self protects the flour. This is the preferred method of woodland storage as the pots are expensive and the paper bags are no good out in the elements .
My preferred method for processing the fruit for coffee is to remove the tannin by boiling, as it removes the oil and makes for a nicer beverage. This needs to be done continuously with clean water for around 4-6 hours and is not an easy process. You need two pots as it is important that the corns, when removed from one pan of boiling water are placed directly into a new pan of boiling water and this process repeated until the water remains clear. Never at any point place the corns into cold water and then heat to boiling as you do not want to bind the tannins and they will also become mushy and ruin.
Once your water runs clear you need to hang the corns in a non absorbent bag to dry and cool naturally. By this time the corns should be dark almost black and full of sugar .
I then use the baking method of drying which needs to be a low heat over several hours.
When using the kitchen Oven I heat it to 100 degrees for 5-6 hours until you can powder the nuggets between your fingers, then store in a airtight container and grind and filter like normal coffee.
Making oil is relatively easy as the acorn is approximately 30% oil. You do still need to remove the tannins and this can only be done by leaching as boiling would also remove the oil.
If you’re in for the long haul like me, you can get all traditional in the leaching.
This entails finding a suitable spot on the inside of a tight bend in a river. Dig a hole at least a meter in from the bank and down to the water level ( this is to be the top of your harvest ). Line the hole at first with fist sized stones and then sand at least ten centimetres thick and place your harvest in the hole. Cover them marking your spot well as the terrain can change an awful lot over four seasons! leave them for roughly a year and then dig them up .
At this point you will notice they are dark in colour, soft and very sweet. Next they need hanging until touch dry, at which point they are then ready to be pressed.
A simple cider apple press works great for this.
The oil will be a buttery consistency and when bottled will separate, simply shake before use.
A word of warning; the oil is a real attractant for the rodents. If you’re keeping it in a woodland, double containers are a good idea .
At this point do not discard the body of the corn, simply mash into honey and bake into biscuits .
The other byproduct of the processes is the tannin soaked liquid remaining from the leaching process. This has many uses such as tanning hides , washing detergent for your clothes and if you reduce the mix by continuing to boil it ,it becomes a very good antiseptic tincture which is great on skin rashes .