Today is World Acorn Day, and what better way to celebrate than with a love letter to acorns, an unsung superfood! We are back on the Montado do Freixo do Meio in Portugal, where the rich traditions of acorn eating are nourishing food sovereignty at local scale. Letter by Alfredo Sendim and Ana Vasconcelos.
Hello, Bom dia.
It’s been a while since our last letter, and we are so happy to be back to write to you about our favourite subject: acorns as an amazing food resource for human consumption.
The acorn is the symbol of Montado do Freixo do Meio, an organic farm in Alentejo, Portugal that was classified as a Nature Protected Area in 2022. Known as “the food of the invincible” due to its unique health benefits, this fruit was a vital resource, part of the culinary and medicinal traditions of the cultures and regions where it is found, underlining the importance of trees and forest ecosystems in human livelihoods since ancient times.
Nowadays, acorns are primarily used as livestock feed. Although, at our farm we are pioneers in the use of this superfood in the modern times, and since 2005 we are the main promoter in the reintroduction of this fruit into the regular diet, creating unique products such as acorn coffee, acorn bread, acorn pâté, burgers and sausages made with acorns, and acorn biscuits and cakes, including our very popular acorn brownie.
Acorn harvesting season is at the door, and today is World Acorn Day, which inspires us to carry this work of connection to the natural ecosystems by relying on this resilient food source and following a conscious way of living.
Superfoods from the woods
The acorn is one of the most abundant fruits in the temperate zone of the northern hemisphere. It is the fruit of the Oak, the genus Quercus. The genus is widely distributed, with some 500 species, both deciduous and evergreen. In our farm and region, the semi-natural silvopastoral system of Montado is primarily composed of native holm oaks (Quercus rotundifolia), cork oaks (Q. suber). With circa 450ha of Montado, it became clear to us that acorns produced by all these trees must be our main food source.
Acorn is a type of nut, like a hazelnut, consisting of a single seed enclosed in a woody shell with a cup-shaped cap. According to biotechnological research, acorns have surprising nutritional and functional characteristics: they are rich in fibre and long-chained carbohydrates (making them particularly interesting for diabetics), with a lipid profile similar to olive oil, gluten-free (particularly interesting for those with celiac disease). In addition to their caloric value, acorns are rich in polyphenols which are compounds with proven antioxidant activity, compounds that may help combat diseases such as cancer and Alzheimer’s.
The acorns of many oak trees are edible while raw, immediately after harvest, while others are too bitter for general consumption without prior treatment to reduce the level of tannins (leaching or volatilisation).
In addition to acorn flour, used in the manufacture of bread and cakes, toasted acorns are also used to produce a kind of coffee, recommended for its beneficial health properties as an antidiarrheal and astringent.
In many recipes, cornmeal can be substituted with acorn flour. Pasta, bread, and cakes made with acorn flour are found in the traditional cuisine of many places where these trees exist, and acorns can be used instead of chestnuts, chickpeas, nuts, or olives in a variety of dishes.
Acorns through the ages
Acorns have been a food source for people in Europe since prehistoric times. The earliest written reference to the use of acorns for human consumption comes from a Greek poet from the 7th century B.C. In medieval illuminated manuscripts, there are several representations that demonstrate how the acorn was an important resource.
Before the introduction of corn and potatoes in Europe, acorns were a staple food in the diet of the poorer classes, just like chestnuts. A 17th century law in Portugal stated: “Any person found shaking oaks or acorns before St. Martin’s Day shall pay a fine of two hundred réis”.
In living memory, acorns were an important source of food during famine times caused by wars or socio-economic crisis all over Europe.
An acorn soup, with beans (more recently with potatoes) and bread, was common in southern Portugal, where sweets were also made from ground acorns mixed with sugar and honey. There as in Spain a very common way to prepare sweet acorns for human consumption, and still practiced today, is to grill them over the coals of a hearth.
Until recently, humans lived in close connection with their environment, a relationship that has nearly disappeared today with the development of a more urban lifestyle. Nowadays, while many older people associate acorns with difficult times, and prefer not to eat them, younger generations associate acorns only with pig feed.
Refining the harvesting process
Our motivation for reviving acorns as a food source for modern times is based on multiple reasons:
– add value to native and spontaneous species on a semi-natural ecosystem,
– super abundant fruit of an already installed system,
– trees need no planting, pruning, watering or fertilisation,
– healthy, nutritious, delicious food,
– contribution to food sovereignty on the local scale while raising awareness.
When November arrives, and the last olives are being gathered, the rush starts to collect acorns from the woods. The Montado, as a semi-natural ecosystem, does not allow harvest as easily as in an orchard. The trees are not in rows; the soil is partially covered with a biodiverse understory, and there is heterogeneity in the production from tree to tree and from year to year.
In the last couple of years, our investment in better equipment and processes has been significant, and we now have become more efficient and confident in the harvest and post-harvest processes:
- Survey the Montado and mark the trees or areas where it is worth harvesting;
- Gather the acorns in small mounds using an air blower machine attached to a tractor;
- Collect the acorns (cleaned of detritus and stones) into boxes using an aspiration and sorting machine attached to a tractor.
At the farm centre, with the help of appropriate machinery, acorns are first dried in an industrial dryer, then shelled and finally sorted into different sizes and qualities. At this point the fruits are quite ready to be stored or allocated to the different needs.
Recipes for food sovereignty
At Freixo do Meio, the main acorn products are i) dried-shelled acorn, ii) acorn flour, iii) roasted acorn infusion. These products are either sold to local or international partners (retailers, restaurants or bakeries), or are the base for other products to be consumed or sold in Freixo do Meio.
At our Organic Farm Shop we offer more than 10 acorn-based products. At the farm’s canteen, where we serve large school classes and small groups of tourists, acorn dishes such as soup, croquets, hamburgers and the beloved brownie are permanently on the menu.
Since 2005, we have cooperated with the biotechnology school of a Portuguese university to better understand the potential of acorns for human consumption, as well as with other institutions, product designers and chefs that support us in recovering old ways of cooking acorns and developing new recipes to showcase the acorn’s delicious and nutritious potential.
Our main intention here is to be connected to our home ecosystems by eating amazing and real sustainable food.
Since this resource is so abundant all over the world, we follow our instinct to reveal all of the knowledge we have gathered on this topic. Last year we initiated the Acorn Academy. All aspects of ‘forest to fork’ are shared in a fundamental and practical way in a three-day course. The last event was in September, and the next Academy takes place at the beginning of 2026.
To end on a sweet note, we will share our acorn brownie recipe, as definitive proof that acorns are nutritious and delicious!
Acorn Brownies (gluten-free)
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8 organic eggs |
Separate the egg yolks from the whites. Beat the sugar with the yolks. In another container, add the dark chocolate with the butter and heat in a bain-marie. After the dark chocolate is melted, add the egg yolks and sugar. Mix and add the acorn flour and finally the beaten egg whites. Place the dough on a baking sheet lined with parchment paper. Bake in a preheated oven at 180°C for 40 minutes. |
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