Making Acorn Flour

 ~Tá dearcain an-úsáideach

Red Oak in glade

WARNING: In an effort to not kill my readers, I should emphasize ACORNS ARE A NUT.   If you have tree nut allergies, do not experiment with acorns before consulting with your health care professional.

Acorns can be used for many things:   fodder, ink and dye, and you can eat them.

Acorns are one of the oldest pre-agricultural human foods.  They are abundant, easy to gather (if you don't mind being cursed out by squirrels) and once oaks are established, they produce for longer that a human lives.  And Acorns are free for the taking!

But today there are only two human cultures who use acorns with even semi-regularity: American First Nations and Koreans.  By the time of recorded history in Europe, acorns were considered famine food, what people ate when they were desperate.  One wonders how good starving Europeans could have been at processing; it's unlikely the skills to make acorns palatable survived with such infrequent use.   Despite the  abundance of acorns and, currently, free cost, there are some drawbacks for commercial use:

- An oak tree takes about 20-40  years before producing acorns.   If you're an long lived species, like elves, no problem.    But since this the average time humans take to mature to adulthood, it's not ideal for starting a staple crop.

- Oaks do not produce reliably every year.  Many trees alternate mast years, that is, one year they dump acorns so thickly you're still walking on them in the winter, and the next, there's hardly any.    Though in my personal experience it's not that extreme: just a lot less acorns in the off year, but still enough. While one tree is under producing, another, across the stream is dropping acorns like bombs.  So mast years appear to be dependent on water, weather and other environmental factors.

- Acorns require leaching to remove tannins which, in large quantities, are toxic to humans. And believe me, acorns have a lot of tannins. Bite into one and it will dry your mouth out and you won't be able to swallow it. Traditionally leaching was done in baskets in streams, or buried in soil.  Some Peoples ground and then leached them, pouring water through the meal.  Grinding first and leaching can be faster, as can using hot water.  But nutrients are lost, and, in the case of hot water, leaching it can go horribly wrong and fix the tannins in the acorns permanently, making them inedible.  

- Oak trees were valued more for building and firewood by colonial cultures, reducing the amount of oaks producing acorns for peoples still eating them. I could see how this turned into a downward spiral and people turned to quicker growing crops.  

I've been gathering and processing acorns for almost 4 years, after first researching the material of people rediscovering this staple. For those who want to try their hand at making and using acorns for food, this is how I do it:

1. Gather acorns.  That's obvious, but you need to identify oaks.  If there are no oaks on your property, best bets are public parks or right of way.  Legally you can gather from pavements besides people's houses and property, but please ask for permission before going onto private property.  Be polite and respectful.

 

Identifying oaks: The two main types of oaks are white and red.   White oaks have the round lobbed leaves.  Red oaks are pointed.  There are many more sub species and oaks hybridized so easily even experts can have trouble telling them apart.  But, as far as I know, all acorns are edible.

Much is made of White Oaks, which are the Holy Grail of foragers. Allegedly their acorns need no leaching.  But the best I've found are some that I could eat raw, if I had to, but were far from pleasant.  Research that suggests humans vary in their ability to taste tannins in acorns.  Unfortunately, this does not mean these acorns are less toxic to the individuals.  According to this document, ALL ACORNS MUST BE LEACHED.  In addition to removing tannins, which not only taste bad but interfere with nutrition, acorns need their phytic acid removed or neutralized(more in notes at bottom of page). 

2020 Harvest

 

I'm so glad I always leach any acorns I gather.    

 

 

2. Shelling/Hulling:

Once I gather the acorns, I shell them.  Some people use a rock or hammer.  Resourceful folks have made special mills to hull in mass.  Good on them!   I use a nutcracker and a bowl, usually while I'm watching a program.  

3. Leaching:

All acorns need to be leached.  Once I  shell the acorns, I put them into a sturdy plastic container, fill it with water and close the lid.  If the container is to be outside, a lid is ideal because squirrels WILL steal them.  Sometimes when I have too many, I put them in buckets and fill them with a lot of water which is a deterrent.  But as they acorns leach, that is get sweeter, the squirrels get bolder.  One has to watch them carefully.

Every day I pour the water off, and fill it again.  It's not the most efficient leaching method, but without a stream or river, it gets the job done.  The leaching process on average takes anywhere from a couple weeks to a month.I will know it's finished when the acorns are completely saturated AND when I break one apart and nibble on it it isn't dry and bitter.  Personally I like a little nutty bite to the flavor. And I worry if I leach them bland, I'm losing nutrients.  But they should not dry the mouth out.

4. Drying:

I dry before grinding because I find the acorns develop a lovely nutty smell that way.  But either will work.    For ease of grinding, I only half dry them.  Ideally this takes a week.  If it's taking longer, check the humidity and watch for mold.

 

5. Grinding:

 Once they're half dry--dry on the outside, firm, but still have moister if squeezed-- I roughly chop them in about 1/4 inch pieces, then lay them out on a mesh to dry some more. A couple days to a week later they should be ready to be ground down to meal.

Note:  I dry in stages for two reasons: to preserve flavor and to avoid grinding a rock hard acorn nut which takes...for...ever.

 

6. Final grinding:  The dry meal should be ground as fine as the appliance can get on the first pass.

Once a batch is all ground, I sift it and grind it again, as fine as possible.  

 

 

Now the flour is finished.  It is best stored in the refrigerator in an airtight container.  

Yield: A paper grocery bag filled with acorns usually yields about 8 cups of flour after about a month of work.  

 

Flour properties: 

The best flour I've made is a light buff or tan color and has a rich nutty flavor.  Darker flour means its lower in fat or has dried out a bit more than ideal at some point in processing, but is still usable.  Some insist white or nearly white flour is possible...and fair play to them!   Keep chasing those unicorns!

I use acorn flour like corn meal, 1-to-1 replacement in cornbread.   

Acorn flour has no  gluten, so it must be mixed with other flours if yeast is the leavening.  It is reasonably responsive to soda leavening, though personally I find I must use eggs for the best results.  And mixing in other flour will make a finer texture.  For pancakes, I use a ratio of 2/3 acorn flour to 1/3 of spelt or barley or oat flour.

After baking, it is much darker than one expects.  Pancakes are lighter.  Left over acorn bread can be used for stuffing or breadcrumbs. 

Final note:  I have had no problems digesting acorns.  But I have noticed a tendency for "firmness" in the bowels.  It makes me drink water regularly, like I should be doing anyway.  But this makes me think people who might have kidney trouble should do some research and go cautiously forward.   

New foods can be exciting but health comes first.

Final notes:

Making acorn flour is a lot of work.  But much of that work is passive: leaching acorns sitting in water while I do something else. And if a community was involved, at least the gathering would go much faster.  I would far prefer to tend an oak orchard than plough a field for my staples, and then cut, church, thresh, etc, etc.  Smart people looking at feeding themselves on a small scale stay away from depending on wheat and corn.  Growing grains efficiently requires community effort even on the small scale.  A family or small groups should be relying on beans, peas and other pulses, and possibly potatoes.  And maybe look to the trees...

Humans could resolve two serious issues at once by supporting more tree crops for food production: our growing food insecurity and environmental degradation.  Chestnut, Oak, Beech, and of course the standard nut trees have fed cultures for aeons.  There is the problem of nut allergies. But for those who can eat nuts it would help quite a bit to relieve the burden. And they're tasty too!

Trees support the soil, clean the air and give us food.  The trees could save us all... if we let them.

Further reading:

 BULLETIN OF PRIMITIVE TECHNOLOGY SPRING 2014: 

No. 4774Do Sweet Acorns Still Need To Be Leached?

By Arthur Haines, Delta Institute of Natural History

 

https://static1.squarespace.com/static/52765bc6e4b094d525e06bad/t/5810d5d0f7e0abd1f4bd4e7d/1477498321694/Arthur+Haines%2C+Do+Sweet+Acorns+Still+Need+To+Be+Leached.pdf

Excellent information and history.  Also has an alarming detail about phytic acid in other foods:

 

 Phytic acid is a storage form of phosphorous in seeds
(phosphorous is an important mineral for germinating
plants). Phytic acid, which is found in acorns and other
nuts, grains, legumes, and achenes, is another antinu-
trient that is capable of chelating with dietary minerals.
Therefore, phytic acid, like tannins, makes minerals
unavailable to the body (and those mineral pass through
the system without being absorbed). Additionally, phytic
acid can interfere with enzymes we need to digest our
food, such as amylase (for carbohydrates), pepsin (for 

proteins), and trypsin (also for proteins). Therefore, it is
important to limit our intake of phytic acid so that we do
not experience mineral deficiencies and inhibit digestion
of food. It is worth noting that most foods commonly eaten
in the United States today that contain phytic acid have
not been prepared in a way to minimize the levels of this
antinutrient.

That can't be good...

Book of Kells Project: Inking

 

 I thought this would take forever.   But it turned out to be the most successful, glorious, satisfying part of the project.

Firstly, the ink came out a lovely black.  Many sources and people I discussed this with were dubious acorns could be a substitute for galls.   Their position, not unreasonable, was the tannins just weren't as concentrated to work.   My position was that just meant I had to boil them down more.  That is the entire reason galls were preferred, their tannins are more concentrated naturally, correct?  

Secondly, in addition to the lovely color, the ink flowed so smoothly you'd think it was manufactured.  I credit this to double straining through muslin before mixing the iron salts with the tannin liquid.   

Thirdly, in my second batch, I hit the perfect proportions of iron salts to tannin.  If it's too far one way, it's grainy; too far the other, it's more of a dark charcoal wash and needs more time to evaporate to the right consistency.  But if it's perfect, just touching the liquid will leave a dark black stain on the skin that will take a day to wash off completely.  That is ink!

Fourthly, it could handle as much detail as the quill nubs allowed.  This was such a relief for the tiny twined lion heads at the corners.  And a single dip really did go far.  If I was writing at a normal size, I could easily scribe lines long enough to finish a couple sentences at a time without pause.

All was not roses however.  There were some missteps.  For some reason I misremembered the styles used in the Book and I "corrected" some of my thin lines, making them much  thicker than I needed or wanted.  Fortunately, I only did that with one element and it looks as if I "meant to do that".  

And I narrowly avoided disaster by unwisely shaking a nub, causing a large drop of ink to fall.  Fortunately this was done on the color test sheet. 

Another annoying issue was my fumbling straight edges.  Those monks must have been kung-fu masters with straight edges.  After the second smear, I just had to stop before I made it worse and accept my "straight" lines would have a wavy appearance.

It took me less than a week to ink the traced design, which was surprising.  But gall/acorn ink  flows nicely.  It's even friendly to my extremely rusty calligraphy skills.  All in all a joy to work with.  I may never buy ink again! 

 Below is the color test sheet.  On it all pigments and inks will be tested before application.  On the right side one can see the spirals tests of various pen nubs.

 

A final note: all inking and painting was done during the morning, with natural light.  

A Rainbow of Threads: Natural Dyed Yarns - Part 1 Black

~dathanna faoi Bogh Baistí le dath nádúrtha

I am working on a craft project that involves weaving yarn. It's for a meditation practice, so I won't be elaborating further.  However, I was inspired to color the yarn with natural dyes and thought I'd archive the process.

There are several threads, all a pale oatmeal natural colored hand spun wool I traded with another artist.  So for colors that are not black or some shade of brown, it was necessary for me to bleach them, and conviently, it was time to touch up my own bleached/blue dyed hair.  Since I don't do it all over anymore, there was plenty to use on a few strands of yarn.

(Note: when you can't get white wool yarn, and must bleach light beige, sheeps hair is more resistant than human hair to Clairol.  I definitely would not do this for a large piece of fabric or garment.  Start properly with white wool.)

Using boxed bleach worked well enough, though it didn't get the strands pure white, more a lightened/blued ash blond(which the package was).  But light enough for my purposes.  The yellows and blues will be yellow and blue, not muddy goldenrod and dark teal.  Never have been a massive fan of teal.   

Once I separated the lightest of the bleached yarns to be "white"(ish), I was ready to start.


~~~~~~~~~~~~~~~~~~~~~

Black - dubh

Thanks to the ongoing Book of Kells Project, I've acquired a modest competence in making "gall" ink.  I put "gall" in quotes because, we don't have gall wasps locally (at least I haven't seen them on the trees I visit and I visit MANY trees) and I think buying galls online is cheating, so I work with what I have plenty of: acorns.  Can I call it acorn gall ink? 

The principle and result is the same.   Once must however use at least twice as much or more acorns.  Okay the exact amount is whatever it takes to make the ink black.  Not dark charcoal, not dark sepia brown(though it often is in the real manuscript), but black.  

Briefly, this involves leaching tannins from crushed acorns by letting them sit in water for about a week.  At the same time, iron is steeping in vinegar to be mixed later.   This can take a couple days, longer is better.(BoK post making acorn ink).  Because the amount of tannins in acorns are so much less concentrated than galls, one has to boil the water down until it's a thick dark brown liquid before mixing in the iron salts mixture.  But to dye one thread of yarn none of that is necessary.  All that's needed is for the yarn to be thoroughly soaked in the liquids in succession.
  Acorns were crushed with a hammer, then put in water to soak for a week.  Try to use a container with a lid and keep it on or squirrels will fish out your acorns and make a mess...even if they're half moldy from last winter!  Don't worry about small amounts of mold; they won't effect results.  Let the acorns sit a week to extract the tannin.  There's no harm in letting them sit longer, though in the summer mold can develop.  If it got too much just strain it.  If it really bothers you, strain and bring to boil, then cool.  No need to boil down to a slurry like one does for ink.   Then I poured off a cup and a half, just enough to soak the yarn.

The yarn to be dyed was  wetted in water, thoroughly soaked so all the dye substances penetrate it.  This is true for all dying.  First i gently squeezed the extra water out, then put it in the bowl of acorn tannin and let it sit a while, maybe 5 minutes.  Remember this is a very small fabric piece..each yarn strand might be five feet.  

Once it was thoroughly soaked, I gently poured maybe a half cup of the iron vinegar onto it.  The results are instant and dramatic: the water turned inky black.  I poked the yarn down with my finger tips, making sure it was well mixed in the black ink.

NOTE: People with sensitive skin ...or who don't want black fingertips for the day...should use  latex or rubber gloves.  I don't have sensitive skin and so am a bit blase except with the strongest chemicals.

After leaving the yarn in for a few minutes, I took it out, and gently squeezed the excess.  DO NOT WRING IT OUT OR RINSE.  Leaving it dry first will make it more color fast, though iron and oak tannin is pretty damn color fast.   It was a hot day so I draped the yarn on a bush and it dried in less than a half hour if that.  Not every color should be exposed to sunlight so soon after dyeing, but were talking about oak tannin, so....

Agus sin e!   One black piece of yarn.  Not as dark as I wanted, but good enough for the project.  

Next:  Part 2 - Brown





 

Book of Kells Project: Oak gall, er, Acorn ink

Or, "What to do when Snubbed by Gall wasps".

 

Alas, some corners will be cut in the interests of convenience. For instance, I will not be using vellum. Smooth watercolor paper will have to do. Frankly, the monks might have preferred paper if they’d had access; the ability to make even sheets of paper, in standard size and thickness would have taken a lot of headache out of the picking out quality calves skins.

But gall ink is something anyone who lives near oak trees can make. Or could if we had gall wasps.

Fortunately acorns contain enough tannin to be going on with. To make ink you need to leach the tannins out of the acorns. The advantage of galls is the high concentration. In absence of galls, one just has to use more acorns and reduce the ink brutally. As it is, I regularly forage for acorns in the fall as a wild food source, so I had enough left over to experiment with.

Oak gall (or acorn) ink is a marriage of tannin and iron salts(iron sulfate). This technique will work with any tannin rich nut, bark, or hull, but different plants will have different shades. Oak gives a color anywhere from an ash greyish brown to true ink black, depending on concentration. Chestnut is brown to a very dark blackish brown, but if you have oak ink beside it, you can see it’s not true black. Even coffee will give a dark brown, but people who have experimented say the ink is oily or shiny and doesn’t flow well. Others recommend walnut or sumac. There’s certainly plenty of room for experimentation. But I quite like the results from acorns, if the gall wasps insist on snubbing us.

The first step is to gather acorns in the fall. If you are foraging for food, use the cracked, slightly moldy, squirrel nibbled ones. It won’t matter for making ink. To learn, start with a couple of cups unhulled. Using a nutcrackers, hammer, or even a rock, crack all the acorn shells. You do not have to hull them. There’s tannin in the shell and nut; you just want to crack it so the nut will leach quicker.

Dump the acorns in a waterproof container large enough to hold twice the amount with at least a couple inches to spare. I use a large plastic box of the sort nuts come in. This has the advantage of being able to see at a glance how dark the water is getting and a lid that keeps the squirrels –and any other wild freeloaders—out. But any waterproof container will do. Fill the container with enough water to cover the acorns plus an inch. You can use more, but your reduction will be longer.

Set aside in a safe place; if you have a lid you can put it outside and let it sit for at least a week until the water is a dark brown. If you don’t get to it immediately, no problem. It won’t go bad, though if you don’t have a lid, it can evaporate.

[iron salts img]

Meanwhile, you need to make the iron salts. Get a glass jar that’s at least 8 oz. I prefer a pint jar. DO NOT USE A LID. The mixture you are making will produce gasses that if contained could explode. The gasses themselves are (relatively) safe. You need iron bits—scraps like rusty nails and wire are used, but I usually have iron oxide from other art projects and I prefer it for evenness. If you are using garage and shop scrap iron, try to get as much dirt and soil off. If you’re using iron oxide powder, two tablespoons should be more than enough. If scraps, a quarter to half a cup. Put the iron in the jar, then fill the jar with enough vinegar (white is best) to cover them completely. Set this jar in a safe place it will not be tipped over, is out of reach of pets and children. Outside if fine IF it is sheltered from rain water. Water will dilute the solution and make it less effective when interacting with tannin.

If you mix iron solution up the same day as the acorns started soaking, it will be plenty ready in a week. In a couple days, you’ll see bubbles in the vinegar as it interacts with the iron. Gently stir the mixture if it seems to be too calm.

Wait a week.

Now most of the acorns should be waterlogged, sitting on the bottom of their container . The water should be a dark brown, the darker the better. Empty the whole mix, nuts, shells and tannin water, into a stainless steel or enamel sauce pan. DO NOT USE CAST IRON. That can work, but it’s hard on the pot unless it is a dedicated dye/craft pot. Heat to boil, then simmer with a lid, for an hour.

Now every bit of tannin has been extracted. There will be some oil on the surface. It’s just acorn oils, and won’t affect the finished product. You want to strain the acorns out. I use a strainer lined with muslin cheesecloth and two pans. You might need to strain a couple of times, folding the cheesecloth in half. Ideally you want to remove all small particles. Remember you are making ink.

Discard acorns and the acorn grit in yard compost if you can.

Now you should have a dark brown liquid clear of debris. In a small stainless steel pan boil it then reduce to a vigorous simmer. Stay in the kitchen or nearby to keep an eye on it. It can reduce fast, in a half an hour , especially a small test batch of a pint , and you don’t want to burn the pan. If you started out with a cup, reduce it to a quarter of that. It will barely cover the bottom of a small pan, but this is the concentration you need if the gall wasps have snubbed you. Some people use a double boiler method. If I start with a pint of boiled , strained acorn tannin, I expect to have about a half a cup.

Once is reduced, cool to room temperature and transfer to a 8z or pint jar. You want some extra room. Alternately , before transferring the liquid, you can warm the jar with hot water, dump the water, then fill it with the tannin solution straight from the stove. If you don’t warm the jar it will crack.

Once the jar with tannin solution is cool, get the iron solution. I don’t have precise proportions because I’ve only done this a couple of times. But if in doubt start with less and add more by small bits. DO THIS OVER A SINK.

For a cup of reduced tannin, add a tablespoon of iron salts to start with

For a pint, start with two tablespoons.

Immediately there will be a reaction, a fizzing of bubbles. If your container is big enough you should be fine. If not, thank goodness you’re over a sink!

Wait for the reaction to stop. I stir lightly with a stainless steel teaspoon to make sure everything is reacted. You should now have a black or nearly black liquid. If you’re not happy with the color, add a little more iron vinegar.

Now it’s possible the addition of the iron salts diluted the ink more than ideal. Just let it sit out a week and it will evaporate down to a nice concentration. You can test it with a brush, paper towel or even a finger (I’d use the pinkie because a good batch will stain skin for a couple days). If all has gone well, it should stain paper or your skin black like ink...which it is.

Once you're happy with the concentration, put it in a jar with a lid. I add a drop of grain alcohol for preservation out of habit from making tinctures. But it is possible with all the tannin no preservatives are needed. After all this work I’m just extra careful.

Now you have ink!

[samples]

Next: False Orpiment: how not to die of lead poisoning when following in the footsteps of artistic monks.