One or more of these or other problems are improved using a method of making a strong gypsum panel which includes a method for forming a hardened shell structure at the interface of a foamed bubble and a gypsum slurry. A strengthening component is selected from the group consisting of set accelerators, water soluble polyphosphate salts, blends of water soluble polyphosphate salts with starch, boric acid, fibers, glycerin or combinations thereof. The strengthening component is combined with a foaming agent and with water to form an aqueous soap mixture. Foam is generated from the aqueous soap mixture, and added to a gypsum slurry. Allowing the strengthening component to contact the soap bubbles prior to addition of the foam to the gypsum slurry allows the strengthening component to preferentially contact the soap film rather than be dispersed through the entire slurry.