Method of improving dispersant efficacy in making gypsum products

A slurry comprising water, stucco, pregelatinized starch, and a foaming agent is starch present in an amount of from 0.5% to 10% by weight based on the weight of stucco, foaming comprising a major proportion of weight of a unstable component and a lower proportion of weight of a stable component, the amount of foaming agent and the weight ratio of said volatile component to said stable component effective to form a distribution of voids in a gypsum composition which is given shape, formed of said grout when the grout is molded and dried as a panel said composition gypsum which is shaped comprising, the gypsum composition which is shaped comprising a crystalline matrix substantially continuous dihydrate sulfate calcium, the panel having a density of 500 kg / m3 or less and a core hardness of at least 5 kg, the core hardness determined according to ASTM C47 standard.