Ever wondered about the heaps of acorns you notice in the park each autumn? How there seem so to be so many, and why nobody seems to bother collecting them, and whether or not you can eat them? Well, I have good news and less good news for you! The good news is you can make like a squirrel and eat acorns in the form of delicious acorn flour- the less good news is it takes a little effort, a few simple tools, patience and an oak tree having it’s “mast” year.
Oak trees don’t produce stacks of acorns every year, instead, every few years they go big. It’s easy enough to tell if an oak tree is having a mast year and has ripe acorns – you will see them scattered all over the ground around it, as acorn foraging is not a common past time here in Australia and we don’t have any squirrels to beat you to it! Acorns are packed with lots of nutrients, fats and protein, but they are also packed with stacks of tannins which make them bitter and indigestible (not to mention unpalatable) to humans, so they need quite a bit of processing before they can be eaten in the nutty and naturally sweet form of acorn flour.
Collect your acorns. Collect freshly fallen acorns – these usually have a dusky patch at the top where the cap recently detached and are darker in colour than those that have been lying around in the sun a little longer.
Step two: float test your acorns. Submerge in water and discard any floaters – they’re likely to have been nibbled on the inside.
Step three: Blanche your acorns for easy shell removal.
Step Four: Crack acorn husks while they are still hot, using the trusty towel and hammer method illustrated below…
Step Five: excercise a little quality control whilst cracking – some acorns may have passed the float test but will still obviously ben spoiling. You can either discard the whole acorn or cut away the “bad” bits and feed them to your chooks or a compost bin.
NB: This is not a spoiling acorn, it’s an “activated” acorn – ready to sprout! They are fine for turning into flour.
Step Six: Remove husks from the nut meats. Depending on your particular oak tree this may be easy or hard. If husks seem really stuck to the nut meats then you can easy things up for yourself by drying out acorns and husks in a dehydrator for 20 minutes or so before attempting to remove husks. Some varieties are just so easy you can skip this step.
Step Seven: Leach your acorns of their tannins. One of the main reasons acorns aren’t more commonly eaten is that they are packed with bitter tannins that make them inedible in their raw state. It’s easy enough to hot-leach these tannins right out of them though. To hot leach acorns, place nut meats in a large saucepan and cover with double their depth of water. Bring to the boil. Simmer for 30 minutes – 1 hour. Drain and rinse acorns in a colander. Repeat until the water runs cleaner when rinsed through acorns and when you nibble the nut-meats you can not taste any bitterness. This can take between 3 – 6 times in our experience, as different varieties of oak contain differing tannin levels.
Step Eight: Blend up acorns into a paste using a food processor or grain mill. Spread paste onto dehydrator trays (if you don’t have a dehydrator you can pop them on baking paper lined oven trays and place in a very low oven. Dehydrate for 20 minutes. Crumble mix and return to the dehydrator for another 20 minutes, or until the mix is very dry.
Step Nine: pass the dried paste through a grain mill or a very fine sieve, and voila! Beautiful delicious acorn flour is yours!
Notes: Chooks also love acorns! Ours happily eat them at the cracked stage, a cheap and fattening food for these Faverolles (foreground)!