To determine crude fiber in flours, feeds, and feedstuffs. Crude fiber is the loss on ignition of the dried residue remaining after digestion of the sample with 1.25% H2SO4 and 1.25% NaOH solutions under specific conditions. This method utilizes the Oklahoma State filter screen or the Modified California State Buchner funnel for filtration and uses prepared ceramic fiber as a filtration aid instead of asbestos. This method is applicable to grains, meals, flours, feeds, and fiber-bearing material from which fat can be extracted to leave workable residue.