Line a jelly-roll pan with several layers of paper towels. Spread cooked grains out into a thin layer on paper towels. Let stand 1 to 2 hours to dry out surface moisture, stirring grains occasionally. Heat oil in a large Dutch oven until a thermometer submerged in oil registers 375°F. Do not use a smaller pot (moisture in the grains will cause the oil to bubble up vigorously). Add 1/2 cup cooked grains to oil; do not add more than this, or oil may bubble over. Cook 4 to 5 minutes or until grains are browned and crisp; do not allow temperature of oil to drop below 350°F. Remove fried grains from pan with a fine wire mesh ladle; drain on paper towels. Repeat procedure with remaining grains, 1/2 cup at a time.