Every year in March, the men of the São Francisco community go up the Iratapuru River to the Reserve where the castanheiras are found. There, they collect 70% of the fruit that has fallen to the ground over a period of 3 months, the rest being left in situ to feed the animals and allow the forest to regenerate. This sustainable forest management is certified by the FSC (Forest Stewardship Council).

The capsules are then broken on the spot and the gathered castanhas are washed and sorted in the river: those that float are discarded, the others are brought back to the community and given to the women who take over. The castanhas are extracted from their shells and then grated.

By mixing the shavings obtained with water, the women obtain a white paste that they work by hand for several hours to obtain a very white milk. After the oil has been removed, only a dry mass called torta remains from this paste. These three foodstuffs, milk, oil and torta, are used every day to feed the whole family. When young mothers do not have enough milk to feed their babies, they give them the protein-rich milk from the castanha nut to drink. Castanha oil has 70% unsaturated fatty acids and is used to make the products in the Ekos Castanha range.