Meet the 3 bases
of chemical leavening in baking
Baking soda is one of the best elements you can incorporate into your baking efforts. The ingredient lends to raising the dough. But like in all good things, chemical leavening, too, has its flaws. Baking soda can take a cookie from “wow” to “yuck” so it pays to know the difference in each reaction. AIB produced, Chemical Leaveners in Baking, a free ebook to help explain in further detail the science behind these biocarbonate sources.
Sodium bicarbonate is the most widely used traditional (alkaline) portion of chemical leavening. Commonly referred to as baking soda, sodium bicarbonate is inexpensive, easy to handle, has a high general purity, and lacks an aftertaste. It is an ideal carbon dioxide source and acid neutralizer.
Sodium bicarbonate is available in different grades based on particle size, which affects many qualities in baked products, including the solubility, reaction rate, and shelf-life stability. Grade 2 is most commonly used. When a faster hydration rate is desired, bakers often use the finer grades. Bakers choose coarser grades when looking for a slowed reaction. The shelf-life of sodium bicarbonate is three years.
Bakers often use ammonium bicarbonate in cookies, crackers, and low-moisture products and it’s a type of chemical leavening. Carbon dioxide is released when the bicarbonate source is heated. Ammonium bicarbonate can trigger the release of carbon dioxide through chemical decomposition. At ambient temperature, ammonium bicarbonate will decompose slightly in a batter. With the addition of heat, the ammonium bicarbonate rapidly decomposes into carbon dioxide, ammonia, and water — even without the addition of an acid or a water source. In addition, the ammonia portion increases cookie spread by altering the protein. The shelf-life of ammonium bicarbonate is one year.
Potassium bicarbonate is an alternative source of carbon dioxide that also reduces sodium in bakery products. Often avoided in the past due to its aftertaste and high cost, bakers are now using it more and more in products where sodium reduction is desired. Potassium bicarbonate reacts closely to sodium bicarbonate, releasing carbon dioxide and water into the system with the introduction of heat and water, and the release of temperatures that mimic sodium bicarbonate. Potassium bicarbonate also has a similar pH to sodium bicarbonate, but requires more of the product to react completely with the acid salts. Potassium bicarbonate has a shelf-life of one year.
The description of all three leaveners provides great insight into the practicality of baked goods. And because chemical leaveners are used as an essential ingredient it’s best to know the differences of all three. Our ebook, Chemical Leaveners in Baking, is the perfect companion to build your knowledge. It’s available here and for free.
What questions do you have about chemical leavening? Let us know in the comments.