This is Frontier's nitrogen-flushed double-wall silverfoil pack. Some Frontier packs are double-walled wax-lined paper.

Single-acting baking powders have Alum (sodium aluminum sulfate) as the acid. Single-acting baking powders react slowly at room temperature and release more of the gas when heated. Single-acting baking powders are better for products that will sit a while before being cooked.

Layer cakes, cookies, biscuits, and many other bakery products are leavened by carbon dioxide from added baking soda (sodium bicarbonate). Added without offsetting amounts of an acidic substance, sodium bicarbonate tends to make dough alkaline, causing flavour deterioration and discoloration and slowing carbon dioxide release.

Addition of an acid-reacting substance promotes vigorous gas evolution and maintains dough acidity within a favorable range. Satisfactory acid compounds include Alum, cream of tartar (potassium acid tartrate), sodium acid pyrophosphate, and various forms of calcium phosphate.

Instead of adding soda and leavening acids separately, most commercial bakeries and domestic bakers use baking powder, a mixture of soda and acids in appropriate amounts and with such added diluents as starch, simplifying measuring and improving stability. The end products of baking-powder reaction are carbon dioxide and some blandly flavoured harmless salts.

All baking powders meeting basic standards have virtually identical amounts of available carbon dioxide, differing only in reaction time. Most commercial baking powders are of the double-acting type, giving off a small amount of available carbon dioxide during the mixing and makeup stages, then remaining relatively inert until baking raises the batter temperature. This type of action eliminates excessive loss of leavening gas, which may occur in batter left in an unbaked condition for long periods.