Ash is the inorganic residue remaining after incineration, often as part of the proximate analysis. This analytical method outlines a procedure to measure the ash content of high-fat, low-fat, and defatted soy flours. A sample is placed in a previously ignited, cooled, and tared porcelain crucible and then incinerated in a muffle furnace at 600°C for 2 hr. Crucibles are transferred to a desiccator, cooled to room temperature, and weigh immediately. Due to the hydroscopic nature of ash, cooling time and sample load in the desiccator should be strictly controlled.