A gypsum slurry is described that includes water a hydraulic component comprising at least 50% calcined gypsum by weight based on the dry weight of the hydraulic component, foam, a defoamer a polycarboxylate dispersant having olefimc unsaturated mono-carboxylic acid moieties and (poly)oxyalkylene moieties, a first portion of a retarder and a second portion of a retarder In some embodiments of the invention, the defoamer is combined with the dispersant prior to being added to the gypsum slurry The defoamer and dispersant can be added as a physical mixture, wherein the defoamer is attached onto the dispersant polymer or a combination thereof In some embodiments, a gypsum building panel is made from the gypsum slurry.