Oak

Oaks (Quercus species) are large, long-lived hardwood trees found across the Northern Hemisphere. While best known for their timber, oaks also produce edible seeds — acorns — that have been a food source for humans for thousands of years. Acorns are starchy and nutritious but contain bitter tannins that must be leached out before eating.

For many Indigenous peoples of North America, acorns were a dietary staple, ground into flour or meal and processed into porridge, bread, and other foods. Different oak species produce acorns with varying levels of tannin; white oaks tend to be milder than red oaks. The practice of acorn processing represents sophisticated traditional food knowledge.

Oaks are not native to Australia, though some species have been planted here. Acorn foods are very rarely encountered in Australian commerce but remain culturally significant in Indigenous North American, Korean, and some Mediterranean food traditions.

Wild Source
photograph to come — from twenty years of markets, farms and kitchens

How it's produced

Acorns are gathered from the ground beneath oak trees after they fall naturally in autumn. This is a harvesting activity rather than farming — oaks are rarely cultivated specifically for acorn production, though some Indigenous land management practices encouraged productive oak groves.

Traditional acorn processing involves shelling the nuts, grinding the kernels, and repeatedly leaching the meal with water to remove bitter tannins. The resulting flour or paste can then be cooked. This process is labour-intensive, which partly explains why acorns fell out of mainstream Western diets once grain agriculture became dominant. Some modern producers in Korea, Italy, and the United States have revived acorn foods as specialty products.

What it costs the planet (per kilo)

Carbon ≈0.5kg
Freshwater ≈130L
Land ≈0.4

≈ Estimated from its category — typical for vegetables, not measured for this item yet. Sources & methods →

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