Walnut

Walnuts have brownish skins that are full of tannins, an antioxidant that is naturally bitter. Some people may want to remove the skins to reduce the bitterness or to create a finished product that includes only the mild nut flavours. The skins can be removed by blanching the walnuts with water, which would extract most of the tannins. However, removing the skins may also reduce some of the health benefits of walnuts.