Processing acorns for food. Acorn coffee and flour.

[Hungry Cat Wilderness]

This autumn I have processed acorns for food.

I live in southern part of Finland where oaks can still manage to grow. Winters in central and northern parts of Finland are too heavy for oaks. Even tho oaks grow here in the south, acorns are totally unknown as food source. Native Americans have used acorns for food for thousands of years. Nowadays acorns are a forgotten food source in most part of the world.
Before oaknuts are edible for humans, they have to be processed. Tannins, which make them bitter and inedible, have to be removed by leaching. Process is actually very simple and does not require much work or any special techniques. There are two ways how to remove tannins: Hot water treatment and cold water treatment.
In hot water treatment you have to boil acorns several hours and change water all the time. It takes several hours.
In cold water treatment you change water three to four times per day and you have continue this as long as the water changes dark. This can take three to four days, but you have to only change the water.
I had quite a lot of fun with this process. I learned new skill and refreshed old knowledge. I made acorn flour and acorn bread. I roasted acorn pieces and made coffee, both pure and mixed with normal coffee.

I highly recommend testing acorns as food source.

Here is my short video how to process acorns and make them edible and use as flour or coffee.

 

[Robson Valley]

I've tried oak (Quercus sp) acorns. They truly are disgusting with the tannins until the leaching process has been done successfully. The qualities vary a great deal from one species to another.

Once processed, how well do they keep? Is this a treat or a staple of the diet? With the loss of the resident microflora, I can imagine them being very moldy in less than a month.

North America has many different wild species of trees which produce "nuts." Many of those requite no processing whatsoever (walnuts, pecans, almonds, hickory, hazels). Oak mast was prepared under duress. Otherwise, it was a great food resource for the deer and the venison was welcome at anyone's home fire.

Seems to me that paleo peoples across Europe would have used immense quantities of walnuts. Are there any shell middens to support such an idea?

 

[John Fenna]

I like Acorn Coffee - and have yet to bother with leaching the tannins! Acorn flour does need leaching though!

 

[Hungry Cat Wilderness]

I've tried oak (Quercus sp) acorns. They truly are disgusting with the tannins until the leaching process has been done successfully. The qualities vary a great deal from one species to another.

Once processed, how well do they keep? Is this a treat or a staple of the diet? With the loss of the resident microflora, I can imagine them being very moldy in less than a month.

North America has many different wild species of trees which produce "nuts." Many of those requite no processing whatsoever (walnuts, pecans, almonds, hickory, hazels). Oak mast was prepared under duress. Otherwise, it was a great food resource for the deer and the venison was welcome at anyone's home fire.

Seems to me that paleo peoples across Europe would have used immense quantities of walnuts. Are there any shell middens to support such an idea?

Hi!

In Finland we have only one wild growing oak species (Quercus robur), which we call forest oak. I have heard that for example red oaks and white oaks acorns have differences between taste and amounts of tannins.
After the leaching process, it is very important that you dry acorn pieces carefully! You can use drier, owen, sunny palace, sauna (like I did). When the result is 100% dry they can be stored very long time. I have had my processed acorn pieces and flour now one and half months and there is no sign of a mould.
I can imagine that walnuts have been very important food for paleo people.

 

[Toddy]

Food storage is one of those very, very area dependent things.
Where folks lived on chalk, they simply dug pits and used that for storage....long story but the chalk pits and the plants own off gassing when the edge ones sprouted, stopped the rest and stored the majority in really excellent condition.
On St. Kilda folks built above ground cairns, carefully angled to the winds, and used those to preserve fish, fowl, ropes, etc., in what is otherwise a cold, wet Atlantic island climate.
Peat bogs were used to store big balls of butter...nice even temperature, full of tannins and phenols, etc.,
Where I live our ground is sodden wet, and I do mean sodden wet. I've been out in the garden today and there is no way on this green earth that I could preseve anything in our ground. Even spuds rot.
I couldn't, without heat, preserve anything in pots either. Mould grows everywhere the humidity is above 67%.
I spent an hour cleaning down the glazing in my greenhouse, again, because it's all green, again. It was done three weeks ago. We had snow this morning, then the temperature rose to 7˚C, so everything was running with condensation. My strawberries are still producing the occasional fruit in there though

It's a persistent juggle to keep things dry.
Keeping dried meat, fish, fruit or nuts or grains outside of a truly sealed container just does not work here.
That's unfortunately true for a lot of the UK and it's islands. Not all of it, but a lot of it.
We don't have a dry continental cold Winter, we have a very variable constantly above and below freezing wet climate in much of this land.
I'm pretty sure our ancestors hunted and foraged all year long.

I find acorns are best stored freshly gathered, not packed tight because mould is an issue, but stored somewhere that they can air a bit. And if you want flour, make it fresh.....unless you're using modern storage jars and the like, then it keeps for ages. I have no idea how our ancestors managed. I suspect they hung them up in skin bags under cover but airy.
Then it's only rats and mice that are a problem.

I found a Kilner jar of acorn 'coffee' that I'd made three years ago. It's really nice I'm having some just now On the whole I think I prefer the dandelion roots stuff though.

M