Log in

Editor's Picks

The oak tree in Skjomendalen © Gerhard Sørensen-Fuglem and Cecilia Piccirilli Bjerkeset
An oak grows north of the Arctic Circle in Norway
Website Editor | Aug 14, 2023
Unusual symptoms linked to phytoplasma infection in Quercus humboldtiii, Colombia © Eric Boa
Symptoms linked to phytoplasma infection found in Quercus...
Website Editor | Aug 06, 2023
Different names are being used for one species.
Website Editor | Jun 20, 2023

Plant Focus

A small but mature Alabama sandstone oak producing acorns © Patrick Thompson
A Critically Endangered dwarf oak 

Eating Acorns to Save the World

Eating Acorns
Eating Acorns: Field Guide—Cookbook—Inspiration
Marcie Lee Mayer, Oakmeal, Kea, 2019. 266 pages.

Marcie Mayer’s new book, Eating Acorns, has soft “wipeable”covers that seem resistant to kitchen stains and acorn-flour fingerprints, ideal for a recipe book. But don’t be deceived, it is much more than that: recipes for cooking with acorns are part of a message that could help change humanity’s relationship with the environment and bring back a diet that was once the basis of civilization. The book is structured like a meal: an introductory amuse-bouche puts on the table the idea of rediscovering acorns as a 21st century food; an appetizer discusses the acorn itself, leading to an antipasto that describes the process of preparing acorns for human consumption; the main course lays out a smorgasbord of recipes using acorns and acorn-flour, while a dessert section sweetens the palate with an account of current and future projects, and useful advice on that other thing you can do with acorns (plant them to grow trees).

Marcie Lee Mayer grew up in Silicon Valley, where the public consciousness was that “if you can think it, you can create it,” and where Native American peoples had survived on a staple diet of acorns for thousands of years. A primary school teacher introduced her to the concept of processing acorns for food, as a way of exploring Native American culture, and Marcie experimented with acorns collected from the two large oaks that grew next to her home. But she would not return to working with acorns till a trip to Greece taken as a break in her art history studies at UCLA became a decision to relocate and eventually set up home on the island of Kea in the Aegean. The island economy, once centered on the export of acorn caps for the tanning industry, had come to rely on the clearing of oak woodland for constructing holiday homes. The Greek government-debt crisis of 2009 meant that many of these projects were abandoned, and it was the sight of these eye-sores—which so spoiled her chosen island paradise—that prompted Marcie to propose to her neighbors they rebuild the insular economy using their most plentiful resource: acorns. The initiative involved resurrecting acorn-cap collecting and exportation to tanneries in Germany and Turkey, but also the use of acorns as food. She had to overcome many obstacles, including a taboo among the islanders about eating acorns, considered only fit for pigs—for humans only during exceptional circumstances like post-World War II famine.

As acorn-flour and chips are not yet to be found on every supermarket shelf or convenience store, the book begins with detailed instructions on how to make your own from scratch—or rather, from whack: the best way to harvest acorns is while still green and infestation-free, by whacking the branches of your oak trees with sticks. Only wood or bamboo should be used, to avoid damaging the tree; traditional “whacking sticks” on Kea are made from willow, cut during winter and cured by the fireplace. Marcie’s tips are immensely practical: aprons can be made into convenient pouches by sewing front and back sides together, and a heavy-duty zipper at the bottom saves time and effort when unloading. Whacking has even had a beneficial effect on trees in Kea, providing natural pruning, and trees that are whacked biennially are observed to be more healthy and vibrant than unwhacked ones: spare the rod, spoil the oak!

Acorn burger
Acorn oak burger, easy to make from fresh or rehydrated acorn

The process of making acorns palatable is quite complex and involves drying, hulling, and repeated leaching, but as Marcie points out, it is no less complex than harvesting and processing wheat or collecting and soaking olives in brine to remove their bitterness. Instructions are provided for both small-scale and large-scale processing. On Kea, thanks to a crowdfunded project that Marcie set up in 2011, locals can have their oaks hulled in a machine imported from Turkey. One of the reasons that acorns have a bad rap is that their shells make them toxic for most domestic animals, except pigs, which have evolved the ability to spit out the shells without swallowing them. Farmers on Kea can now have their acorns hulled in large quantities, and the shelled acorns can then be safely fed to their livestock.

Leaching in water is required to remove the tannins from acorns. Tannins are good in small quantities (as in wine), but make unleached acorns disagreeable. However, we should be thankful for tannins because they also serve as a natural preservative, and dried acorns can be easily stored for several years without losing their culinary and nutritional value. (For some, the answer is to find acorns that are naturally “sweet”, in other words, they have little or no tannins and are tasty fresh off the tree. See Joan Montserrat’s Member Profile on the IOS website for more detail—available to members only.) Processed acorns can be milled to make mash or flour, and different milling methods are described in the book, together with storage methods and other uses for the various byproducts of the acorn process.

Acorn tortillas
Acorn tortillas: soft, nutty, and rich flatbread

The core of the book, the list of recipes, opens with an account of acorns’ high nutritional value: they are an excellent source of potassium, iron, magnesium, calcium, and vitamin B-6, they are gluten-free and high in fiber, and also contain free radical scavengers: antioxidants that help protect cells from free radicals that may cause damage and increase the risk of cancer and other diseases. But acorns are also tasty and their nutty flavor is said to be characterized by umami, the indescribable fifth basic taste (after sweet, sour, bitter, and salty) that is the Holy Grail of foodies the world over. One imagines that it is acorns that are responsible for the umami found in the highest quality Iberian ham, jamón ibérico de bellota, which according to regulations can only come from pigs raised on 7 kg of acorns a day during feeding season. Umami, sometimes described as an “earthy” taste, is also associated with truffles, which grow as symbionts on oak roots. Might there be a connection?

Seventy recipes cover the gamut from breakfast to dessert. In many cases Marcie has adapted recipes by replacing wheat-flour with acorn-flour, resulting in nutty pancakes, waffles, muffins,  crepes, tortillas, pastas, pizzas, breads, brownies, and cookies. Other recipes use acorns as a substitute for meat, as in a vegan Bolognese sauce for pasta. Some are borrowed from history (acorn savoury biscuits are adapted from a 12th century recipe attributed to Hildegard of Bingen) and some from contemporary sources (acorn pumpkin bread from Julianne Skai Arbor, aka Treegirl and familiar to those who attended the Lightning Talks at the 9th IOS Conference in Davis, California). Then there are recipes drawn from cultures that still incorporate acorns in their daily diet, such as dotorimuk, an acorn jelly popular in Korea that can be served in salads, and a hot acorn drink adapted from Racahout des Arabes, a beverage of Arab origin popular in 19th century France. Many of the dishes and concoctions may strike the uninitiated reader as unusual, but surely none more than the snack “Grub Popcorn”, made by sautéing—in garlic-scented olive oil—live weevil larvae (yes, those you find in the bag you’ve stored your acorns in). Apparently they pop just like corn and are tasty and nutritious, having grown plump on a diet of nothing but acorn. Don’t worry if you think they might make you feel squeamish: you can wash them down with a glass of acorn-infused vodka, the recipe for which is helpfully placed on the same page.

Acorn waffles
Acorn chewy cocoa waffles

The final section of the book describes other oak initiatives Marcie Mayer has undertaken: exporting acorn caps for tanneries to create sustainable income for Kean farmers, developing new applications for acorn extract, community activities such as an Acorn Festival that includes a hotly-contested competition for the heaviest acorn (past contenders have been disqualified for freezing their competing acorn in an attempt to maintain maximum weight, a practice known on Kea as “acorn doping”).

You can purchase Eating Acorns conveniently on Amazon or on Marcie Mayer’s website: www.oakmeal.com. While you are waiting for it to arrive, learn more about her remarkable story by perusing the Article Archive section of her website, particularly an excellent feature by Seb Emina. Marcie received an International Oak Society Special Service Award in 2015 for her initiative on Kea to rehabilitate the age-old industry of processing acorns of native oaks; you can read a full account of her work in her article in International Oaks No. 25, pp. 13-22. You should also view Marcie’s latest presentation at TEDxThessaloniki (and a previous one from 2012). Marcie’s message is irresistible: humans may have forgotten their quercivorous roots, when we survived on acorns, but perhaps now we can return to where we started and know the place for the first time. In Marcie’s words: “The simple act of eating acorns allows every one of us to participate in the creation of a green new world with a braver new humanity.”