AbstractX‐Ray diffraction studies were carried out on the hydrated alumina precipitated during the seeded decomposition of sodium aluminate solution in the presence of glucose, cane sugar and starch (white potato), and the results are considered in relation to the rate of decomposition.Glucose and sugar suppress bayerite formation, may increase crystallite size, and slow down decomposition. Starch is without effect on bayerite formation and increases the rate and extent of decompositio