Collected when they ripened in fall, the Indians dried them in the sun and stored them in large baskets. Dried acorns dipped in clarified sugar can be used as a snack. Roasted acorns have also been used as a coffee substitute. White oaks have sweet acorns that mature the same year they are formed. They only need to be shelled and roasted.
Red oaks have bitter acorns that mature the second year after forming.
This will rid them of tannin. Since identifying oaks can be difficult, the cup of the acorn can help determine if the oak is of the white variety or the red. White acorn cups are smooth on the inside and red acorn cups have wooly hairs on the inside. Many species often have characteristics of another, making field identification a challenge. Since they grow quite large, it is nearly impossible to examine their characteristic crown leaves.