This method determines crude fiber which is the organic residue remaining after digesting with 0.127 M H2SO4 and 0.313 M NaOH. The compounds removed are predominantly protein, sugar, starch, lipids, and portions of both the structural carbohydrates and lignin. This method is applicable to all feed materials such as grains, meals, pet foods, mixed feeds, forages, and the following oilseeds: corn and soybeans.