If you live in California (or anywhere in North America, Europe, or South-East Asia), you likely have an abundance of dominant native oak trees. AND did you know that they produce tasty and nutritious nuts that have been removed from popular culture in cuisine? In fact, the acorn nuts from oak trees are sacred in some indigenous cultures. Much of my inspiration has come from the native Pomo and Chumash (learn more here) and many other Native American tribes – along with the book Eating Acorns by Marcie Lee Mayer from the company Oakmeal. Here in California, acorns were (and can still be) a staple, consistent, and sustainable food source for Native Americans more than any other food. The question now is – why have we shifted from what is free, native and available to what is imported, planted, fertilized, pesticized, harvested, and shipped around the globe?
Why Not Use Acorns
- Time and resources to process
- Large and irregular
- Difficult to place in rows for agricultural machinery
- Slow growing
Why Use Acorns
- Nutritious, abundant, hyperlocal food source
- A native tree that supports habitats of many plants and animals
- No water or fertilization required
- Agricultural technology can be retrofitted from almonds and other nut crops
- Connecting with traditional, native practices and land stewardship
- Perennial one-time oak planting
- Oaks live hundreds of years
Learning Your Oaks
There are two main families of oak trees: Red Oaks and White Oaks (plus Hybrids). Red Oaks (Black Oak, Coast Live, etc.) tend to have more tannins, which preserve the acorns longer but can be challenging to process. White Oaks (Valley Oak, Blue Oak, etc.) have less tannins and often a larger acorn – the downside is that it will not preserve as long (more of a challenge for the Natives gathering without modern storage).
In my humble experience, I have found the Valley Oak (Quercus lobata) to be the most productive oak tree with the largest acorns and low tannin content. Although, California Black Oak (Quercus kelloggii) was the choice acorn used by natives in our area and in much of California – they are relatively large and have tannins to preserve them. Coast Live Oaks (Quercus agrifolia) are by far the most common trees along the Californian coast – the acorns are small and have a lot of tannins.
Work: active 1 – 4 hours
The acorn harvest begins around October and lasts through November, depending on the season. Keep in mind that any time foraging, you are directly interacting with nature – so please be respectful. The foragers rule: take no more than 1/3 of any one food source and leave plants so that they can continue growing. Find trees near water and sunlight with good soil. Pick them off the ground, from a tree, and / or hit the larger trees with a long bamboo stick to knock off high-reaching acorns (traditional practice from natives). Any acorns with holes, rot or damage should be removed for compost or animal feed. The holes are the work of the acorn weevil larvae that rely on the acorn meat to develop. From there, the rest of the acorns can be used. You will likely sort out more later, unless you’d like to do the float test – acorns that float have been eaten from the inside or have rot (toss these).
Time: 1 week – 1 month
After harvesting and removing the leaves and stems from your pile, the first processing step is to “cure” (or dry) your acorns so they preserve without the risk of mold. There are many low-tech ways to do this and, for Mediterranean climates, these will be easier as well:
- Outdoor deck
- Solar dryer
- Hanging sacks
- Wood boxes
- Well-vented greenhouse
When the acorns are done drying, they will rattle within the shells. If you need to be precise about the process, the acorns should have no more than 12% moisture in the end. Considering they begin with 18 – 30% moisture, you can weigh the acorns before and after to calculate a 6 – 18 % difference in weight (18% difference is safer unless you are sure that the acorns have less moisture to begin with).
If you decide against the natural sun energy, using a dehydrator or oven, cracked open at a low temperature (ideally, 100 – 150 degrees F) works well also.
Work: active 1 – 4 hours
Once the acorns are cured, you may shell them using the side of a knife, a hammer, a stone, etc. If the husks still remain on the acorns after shelling, let them dry out further for one day and they should come off easily. Compost any nuts with rot or damage.
Time: 2 – 6 days
Now, blend or chop the acorns into small pieces to create a mash and cover with water in a container (make sure the water does not cook the acorns – nutrients will be lost and tannins not removed properly). While pouring water over the top stir the acorns to release the tannins for a few minutes. Then, drain the water and pour in new water. Cap your container so avoid debris and let sit for one day, shaking or stirring twice a day. Drain and refill the following day, continuing to stir. Repeat each day until the water is no longer dark with tannins. This should take 2 – 6 days. Taste the acorns – if there is a bitter flavor, let it sit longer.
Leached Acorn Drying
Time: about 12 hours
Lay out leached acorn mush into thin layers to dry on cookie sheets or dehydrating trays. The same methods to cure the acorns can be used here to dry off the water from leaching: solar dehydrator, oven, electric dehydrator, etc. – just be sure to account for pests tampering with your precious work. This should take about 12 hours.
Milling Acorn Flour
Work: active 10 minutes
Let the acorns cool completely, then mill into flour. Use a flour mill, a coffee grinder, or a blender. Let the acorns cool again completely before storing in sealed bag or jar for storage (2 years in freezer). Et voilà!!! You made acorn flour!! Check out our recipes here and congratulate yourself for supporting native traditions and sustainable food systems!!
Total Working Time
The total amount of active working hours in the process is 3 – 10 hours, while the total passive waiting time is 2 – 8 weeks. Many people choose not to make acorn food because the process is intimidating. I am here to tell you the process is simple! If I can do it, you can do it!
Support the Oaks
The best part acorn food is that it is a free and abundant food source that will support the native flora and fauna, while supporting the ecosystem services that we need as well (e.g. carbon intake, water absorption, erosion control, climate regulation, etc.). These tree live hundreds of years, producing much of that time to support us and their environment as a dominant, keystone plant species. Like the many other productive and semi-productive native food sources, we and many others rely on these plants. Imagine a world where we planted into the landscape around us and integrated our agriculture into our native habitats…