By Harold McGee
The outer protective coat, called the bran in grains and the seed coat in legumes and nuts, is a dense sheet of tough, fibrous tissue. It’s rich in defensive or camouflaging phenolic compounds, including anthocyanin pigments and astringent tannins. And it slows the passage of water into grains and legumes during cooking. It’s often removed from grains (especially rice and barley), legumes (notably in Indian dals), and nuts (almonds, chestnuts) to speed the cooking and obtain a more refined appearance, texture, and flavor.