Sodium Bicarbonate Uses in Chemical Leavening
Posted by Lisa Unlu on Aug 17, 2016
What is chemical leavening? Chemical leavening is the use of sodium bicarbonate, also known as baking soda, in combination with one or more leavening acids, such as monocalcium phosphate (MCP), sodium aluminum phosphate (SALP), cream of tarter (acidic potassium tartrate) or glucono delta lactone (GDL) to yield water and carbon dioxide, the gas that ‘chemically leavens’ dough. Sodium bicarbonate is available to food processors in a variety of forms and granulations. Chemical leavening enhances a baked product by giving the product greater product volume, a softer crumb, and more uniform cell structure.
Sodium bicarbonate is widely used in the food industry because of its low cost, ease of use, high purity, and absence of aftertaste in the finished product. Using Neutralizing Value (NV), a baker can calculate very carefully how much sodium bicarbonate and leavening acid to add to a product, using very well-known rates of reactions between sodium bicarbonate and various leavening acids. Adding the correct amount of leavening acid based on the amount of sodium bicarbonate, to leaven a baked product, minimizes excess sodium bicarbonate in the finished product. Excess bicarbonate in the finished product can have an effect on pH of the dough, causing it to be browner (which may be an undesirable appearance for the product).
To prevent premature reaction of sodium bicarbonate in a frozen or refrigerated baked product, a baker can use encapsulated sodium bicarbonate or baking blend, like PrimeCAP® Sodium Bicarbonate or PrimeCAP® Bakery Blend, a blend of Sodium Bicarbonate and Sodium Aluminum Phosphate. The fat coating on these ingredients protects them from reacting with water, acids, or acidic ingredients in the dough before baking. When the product bakes, the fat coating will melt at a specific temperature, releasing the sodium bicarbonate or bicarbonate with leavening acid, allowing them to react. A product formulator might include some ‘free sodium bicarbonate' to give the product some initial lift, and then the encapsulated PrimeCAP® sodium bicarbonate to give the product the additional in-oven leavening. The encapsulation ensures that the product will have a protection of the leavening over the shelf life of the product, under refrigerated or frozen conditions.
Bakers producing canned refrigerated biscuits, bread dough or pizza dough would benefit from using encapsulated sodium bicarbonate, as the bicarbonate would be protected from the water in the dough, preventing the bicarbonate from reacting with leavening acids in the formula. A refrigerated biscuit might include one or more leavening acids –fast acting SAPP (sodium acid pyrophosphate, and slower acting SALP (sodium aluminum phosphate), for leavening at two stages during the baking process (double-acting). While the biscuits or dough are refrigerated, the sodium bicarbonate remains protected and unable to react with the leavening acids. This protection gives the product a longer shelf life for the product. The encapsulated sodium bicarbonate does not come into contact with the leavening acids until the consumer opens the package, places the biscuits in the oven and bakes them in their home oven. The fat coating on the encapsulated sodium bicarbonate melts at its specific melting point during the baking process, releases the sodium bicarbonate, allowing it to come into contact with the SAPP and the SAPP, which react to form CO2 and water. The biscuit or dough ‘lifts’ and creates a flaky, soft crumb structure.
Similarly, frozen bread dough or sweet rolls benefit from the use of encapsulated sodium bicarbonate for a similar reason. As a bakery produces rolls for freezing, the dough may be mixed, then sit in a hopper for forming, and then proceed into a blast freezer. The total time for production may be very quick or maybe as long as two hours, depending on the size of a batch of dough. If dough sits in a hopper for an extended period, with raw sodium bicarbonate, exposed to leavening acids, the sodium bicarbonate will react and form CO2 into the dough. Unfortunately, this will leave less sodium bicarbonate for leavening later when the consumer goes to bake the product in their home oven. Ideally, the sodium bicarbonate needs to be ‘isolated' from the leavening acids during the dough forming process. Use of an encapsulated sodium bicarbonate, such as PrimeCAP® Sodium Bicarbonate is the most effective means of preventing the sodium bicarbonate from reacting with the leavening acids before the baking process. Encapsulation keeps the sodium bicarbonate ‘safe' during the dough forming process and into the freezer, so the product will have a longer shelf life than it would otherwise have with unencapsulated sodium bicarbonate. When the consumer takes the frozen product and bakes it several months later, the sodium bicarbonate is released, as the fat coating melts at its specific temperature in the oven, as the dough heats up. The sodium bicarbonate reacts with any leavening acids or ingredient acids within the product formulation, and CO2 (carbon dioxide) forms. As the dough leavens, the texture of the roll lifts as the product ‘rises.' Each product should meet a consumer expectation for the amount of ‘rise' for a given formulation.
We hope this blog has helped you understand why the use of Sodium Bicarbonate for chemical leavening is preferred in the food industry. For additional information, contact Innovative Food Processors, inc. (IFP) at http://www.ifpinc.biz