A method of manufacturing a mineral fiber insulating board comprising i) spraying a formaldehyde free aqueous binder solution onto a plurality of mineral fibers, the aqueous binder solution comprising binder reactants comprising a) a reducing sugar reactant and b) an amine reactant, wherein the reducing sugar reactant is selected from the group consisting of: a reducing sugar; a reducing sugar yielded by a carbohydrate in situ under thermal curing conditions; and combinations thereof, wherein the percent by dry weight of the reducing sugar reactant with respect to the total weight of the binder reactants in the binder solution ranges from about 73% to about 96%, and wherein the percent by dry weight of the amine reactant with respect to the total weight of the binder reactants in the binder solution ranges from about 4% to about 27%, ii) dehydrating the aqueous binder solution such that a dehydrated binder is disposed on the plurality of mineral fibers, and iii) curing the dehydrated binder on the plurality of mineral fibers to provide cured binder in about 0.5%-15% by weight as determined by loss on ignition.