Oak trees are some of the most iconic trees in the world. They are known for their long lifespans, towering heights, and beautiful foliage. But did you know that oak trees also produce seeds?

Oak seeds, also known as acorns, are acorns that are borne in a cup-like structure known as a cupule. Each acorn contains one seed (rarely two or three) and takes 6–18 months to mature, depending on the species. The acorns and leaves contain tannic acid, which helps to guard against fungi and insects.

The amount of tannic acid is species dependant. To make acorns edible, it is necessary to remove the tannins. This can be done through a process called leaching. Leaching involves soaking the acorns in water for several days, changing the water frequently. Over time, the tannins will leach out of the acorns, leaving behind a sweet and nutty flavor.