Acorn Flour

Many of you will know that there are quite a few plants that can be foraged and added to your diet.  In the modern world this is great for a few reasons.  Firstly, the act of going out and spending time outside, taking an interest in the plants around us, identifying them and picking those that we can use to add to our meals somehow brings us closer to nature and can help our mental health.  Secondly, it adds variety to our diet which can have additional health benefits that are associated with helping to establish healthy gut bacteria.  But also, it is a way of getting additional exercise – although the walks take longer and are slower paced.  However, in a traditional hunter gatherer lifestyle, there is a dilemma to be faced.  While there are plenty of plants that can be consumed and contain an abundance of vitamins and minerals, there are few that contain high levels of starch – in other words carbohydrates.  Until the domestication of wheat in the middle east and its subsequent spread into Europe our forefathers had to wait until nuts were in season to be able to gather high energy food that could be stored for a relatively long period of time.  In the UK it seems that hazel nuts were a big support during the winter period.  Middens have been found of the shells that had been left behind by our Mesolithic ancestors who would return to the same areas year after year to process the hazel nuts.  But around the world, wherever there are oak trees, there is evidence that acorns were also harvested for their use as a food stuff.  We have contemporary accounts of how the First Nations North Americans would harvest and process acorns for their flour and it is similar in Europe and Asia too.  Indeed, acorns are still harvested in Poland, Turkey, China and Korea with the resulting flour being available in shops.

So why bother now?  Well, the flour genuinely tastes nice with its sweet nutty flavour.  It is also gluten free so less likely to be an irritant for those that find it difficult to tolerate wheat.  It has an amazing nutrient breakdown containing:

• 50-90 percent complex carbohydrate; • 5-30 percent fat (the healthy monounsatured and polyunsatured fats); • 5-8 percent protein; • contain all the essential amino acids; • are very high in Vitamins B6, Potassium Manganese, and Copper; • are a good source of a large range of other vitamins and nutrients Source:USDA, 2008

And, finally well why not? It is not too difficult to collect acorns and the processing is not that technical, it just takes a little time to go from raw material to finished product.

Ingredients
Acorns – lots of them.  At least 4-5 litres of acorns.  This will make about 400-500m grams of acorn flour.

Method
Collect around 4-5 litres of acorns. It’s easier to think in terms of volume when collecting them than weight. If possible, remove the acorns from the acorn cups and try not to include acorns that have a small hole in them – the nut is likely to have been eaten by a grub.  When home, spread the acorns onto roasting trays and roast at 180-200^oCfor 30-45 mins and allow to cool.  Then comes the deshelling.

Wrap a handful of the acorns in a tea towel and using a mallet – gently hit to crack shells – shell the acorns. Meat in one container – shell in another. No need to hammer the life out of the acorns they only have thin shells and the nut inside will be smashed and if this happens, life becomes harder than it needs to be.  Another easier method is not to have to hit it at all but to just squeeze the top or the bottom of the acorn between your thumb and forefinger on until it pops and then maybe do it again on another end of the shell and then simply unpeel the nut, rolling it out of the shell.  It’s kind of cathartic peeling acorns outside the sun a lovely way to spend as lazy afternoon.  Top tip: let the thumbnails grow a little before shelling not only does it make it easier to unpeel, but it also helps avoid any sharp bits of shell under the nail.

Once you have shelled all the acorns, next comes the leaching.  Acorns are full of tannins and these will give the flour a very bitter taste if they are not leached out. You can leach the tannins by either hot leaching or cold leaching.  Hot leaching requires putting the acorns in a pan with alongside water and heating it until it boils.  The water will start to brown as the tannins are released.  Empty the pan of water top up again with cold water and boil, empty, repeat. keep doing this for a number of changes of water (maybe four or five times) until an acorn does not taste bitter.  Don’t go by the colour of the water, it will always go brown!  Cold leaching is an alternative way. This is the method I used this time.  It takes longer but is less energy intensive.  Put the acorns in a bucket and fill it with cold water, give it a stir and leave it.  Change the water regularly – I changed it at night and again the next morning – carefully tipping it out so you don’t lose any acorns or bits and replacing it with cold water.  he guidance I’ve read on this varies widely on the number of days to keep replacing the water from 7-21.  As it happened, I was not in for the long haul… after 7 days I tested the acorns and they were well leached and had no bitterness at all.

There are alternative ways of cold leaching though.  If you have running water nearby then place the acorns in a porous bag or net and tie it to the bank letting the steam do all the hard work for you. The stream near me is well visited so I wouldn’t fancy the chances of the bag staying put.  Another idea is to put the acorns in your toilet cistern and let the flush do the hard work… I really want to try this method but it is always vetoed!

After leaching, drain the water out and lay the acorns onto trays and dry them out.  You could leave them outside to dry but I put them in the oven at 75^oC with the fan on for a few hours to start drying.  I then blitzed them in a food processor to break them into a course meal before putting them in a dehydrator for 15 hours.  At this stage, they were well and truly dry.  To turn the rough meal into flour, I borrowed an electric coffee mill and finely ground the acorns.

Acorn Flour Uses
So one thing to note with acorn flour is that as it does not contain gluten it does not stick as well as wheat flour.  If the acorns have been cold leached, there is a starch that is present that acts a bit like gluten so cold leached acorn flour sticks a little better than hot leached flour which cooks and deactivates this component.  One thing you can do is to add a third of a wheat or maize flour to the acorn flour to help with the binding.  Other than that, you can use acorn flour in the same way as any other flour.  However here is a quick bannock recipe to start you off.

You can also make a ‘coffee’ from it, using it in the same way you would a ground coffee.  It tastes really mellow and but does not have caffeine, so for some that’ll be a good thing and for others not so good!  A small hint with the coffee though, do not grind it as fine as the flour as it can clog the filter if using something like an aeropress.  So  perhaps grind some at a coarser grade first for coffee and then at a finer grade for the flour.

Acorn bannock
2/3 Acorn flour
1/3 wholemeal flour or use corn meal
Salt
Water
Baking soda (optional)
Olive oil or butter

This is the camp version – the amounts will depend on whether you wish to make one or two bannocks for yourself or a large bannock to be cooked in the oven (Dutch oven or kitchen oven) to be shared with others!

• Mix a handful of acorn flour with a third of a handful of wholemeal flour.
• Add a pinch of salt.
• Add a pinch of baking soda (optional)
• Add a finger scoop of butter or a drop or two of olive oil.
• Mix together well in a bowl.
• Slowly add a little water and mix into the dry ingredients.  Slowly adding a little water at a time until there is a nice firm dough that does not stick to the bowl or to your hand.
• Roll into a ball and flatten so it is about 1cm thick.
• Dust a hot dry surface with some flour (I’d use the wheat flour to avoid wasting the precious acorn flour) e.g. the lid of a Dutch oven or a frying pan or if you are in Wales, a bakestone.
• Place the bannock patty onto the hot surface and allow to cook for about 30 seconds to form a skin on the underside before turning over and doing the same to the other side.  Turnover one more time and allow to cook until it sounds hollow when you flick it with a finger.
• Cut open and add butter, jam, bacon, whatever takes your fancy.  And eat.

There are loads of variations you can make on this basic recipe.  Add dried fruit to the mix, use half a banana instead of water.  Use beer instead of water.  Add honey. It’s all good.