Sodium acid pyrophosphate (SAPP) is a leavening acid commonly found in baked goods.

SAPP is a leavening acid commonly found in baked goods.

Sodium Acid Pyrophosphate (SAPP)

What is SAPP?

Sodium acid pyrophosphate (SAPP) is a leavening acid commonly found in baked goods. It has a neutralizing value of 72 and varied reaction rate of slow to fast depending on the granulation.


SAPP is prepared by thermal dehydration of monosodium phosphate.

SAPP composition

Chemical structure of SAPP


SAPP reacts with baking soda and water as well as reacting with calcium ion and protein in flour and milk for a secondary reaction. SAPP’s reaction rate in a batter depends on the granulation. Different grades are developed for varying applications. SAPP can be used alone or in combination with other leavening acids.

Cake donut production uses a specially developed SAPP that will release some gas during mixing and produce more upon frying to create proper expansion of the donut during frying.

Refrigerated dough for canned biscuits requires a very slow acting SAPP at room temperature, but a rapid and controlled gassing during proofing. This is used to fill and seal the can with dough to displace any entrapped air in the package.

Cake mixes use a combination of intermediate reacting SAPP with MCP, a fast-acting leavener.


SAPP should be used in conjunction with baking soda. The neutralizing value of leavening acids is the ratio of sodium bicarbonate (baking soda) to 100 parts of acid leavener that will bring about complete carbon dioxide release or “neutralization.” For an acid with a neutralizing value of 72, if complete neutralization is desired, you would start out with a ratio of 72:100 parts baking soda : leavening acid. Adjusting the amount of leavening acid to baking soda can raise (decrease acid amount) or lower (increase the acid amount) the pH of the finished product.

SAPPs are available with special design for certain applications, like cake donuts, biscuits or cake mixes. SAPP can impart a bitter aftertaste in some applications. The bitter aftertaste can be masked by using sufficient baking soda and introducing calcium ions, sugar and flavorings. It is high in sodium.