A nut that is grown and harvested from the oak tree. Generally, the acorn is not often eaten, due to their higher levels of tannins, which provide a bitter taste to the nut. The tannins can be removed by continually boiling the nuts in fresh water. This removes the tannins, which color each batch of new water. The majority of tannins are removed when the boiling water is no longer colored. The red and black oak acorns are more bitter tasting than those on the white oaks. The varieties of acorns considered edible are roasted in the shell, similar to chestnuts and eaten as an appetizer. They can also be served raw or baked in main dishes.