Chemical leaveners provide critical functionality to many baked foods, including volume, texture, flavor and more. Not all leavening systems are created equal, however, and producers must pinpoint the desired attributes of their baked food to find the option that will provide the proper lift.

“The selection of a leavening system depends on the desired rate of gas release,” explained Joan Randall, associate scientist, Kemin Food Technologies. “The neutralization value, the amount of base needed to react with the acid, the rate of reaction and the timing of the gas release need to be optimized to produce the desired volume and crumb structure.”

Every baked food has distinctive moisture requirements, desired texture, bake time and temperatures, all of which determine which leavener is best. 

Baking soda, for example, is optimal in recipes that don’t require a high-volume product, such as crackers or cookies.

“Other good candidates are recipes that include acidic ingredients, such as sour cream, buttermilk, lemon juice or other acids that need a strong, immediate reaction to leaven the batter or dough,” explained Songwei Wu, staff scientist, food and beverage, Innophos. “In these recipes, the baking soda reacts with acidic ingredients to produce carbon dioxide gas, which results in the volume. This reaction occurs immediately upon mixing, so it is essential to bake the batter or dough quickly after adding the baking soda.”

Cakes, muffins, biscuits and other airy baked foods require significantly more leavening, however. For these applications, a double-acting baking powder is often best, providing both batter aeration during mixing and rise during baking. 

“In a cake, fine, consistent crumb is desirable,” explained Paul Bright, innovation manager, AB Mauri North America. “And so that’s the leavening system we’re looking for: gassing that happens in the mixer a little bit during floor time, and then as soon as that batter hits the oven, we want it to pop and get that rise.” 

Tortillas, on the other hand, may require different chemical leaveners based on desired product appearance. A single-acting chemical leavening system will result in a soft, fluffier texture during bake, for example, while a double-acting system will yield a more translucent tortilla, noted Yanling Yin, PhD, director of research, development and applications for bakery, Corbion.

“For fried products such as a donut, a late-reaction acid provides a kick during drying to create the tender texture,” she added. 

Mr. Bright emphasized that collaborating with ingredient suppliers during development and testing is an effective way for formulators to select the right leavening system.

“What we’ve seen a lot is collaborating with ingredient suppliers who may have a deeper knowledge of the ingredient so that they can assist with the development,” he said. “If you come into our lab, we can mimic what our customers are doing out in the field.”

Avoid leavening mishaps 

Incorporated correctly, a leavening system supports many key attributes of baked foods. Done incorrectly, the leavening system can all but ruin a product. 

“Proper usage level is important,” said Mary Thomas, R&D senior manager, Lesaffre. “Too much leavening, and the product could have coarse grain and a bitter taste. Too little and the baked product will not rise to the correct volume.”

The base and acid within the system must be properly balanced as well.  

“Unbalanced leavening systems will affect the appearance, flavor and texture of the end product,” said Nita Livvix, R&D manager, B&G Foods. “If too much sodium bicarbonate is left unbalanced with leavening acids, the product will have a coarse, dark crumb structure and a ‘soapy’ flavor. If too much leavening acid is used, the product will be pale and, depending on the leavening acid being used, the flavor may be bitter or sour.”

To avoid this, producers must understand their ingredients’ neutralizing values to calculate the necessary amount of bicarbonate and phosphate in a formulation. 

“Leavening acids all have different neutralizing values and can release gas at different rates, so it’s key that formulators take this into account to counterbalance and make sure their process and math are correct,” Ms. Wu said. 

Temperature is also an often-overlooked aspect of production that may negatively affect the leavening process. Bakeries typically have higher-than-average ambient temperatures, Ms. Randall noted, which can cause an unintended acceleration of the chemical reaction.

“Higher-than-usual ambient temperatures can cause overproofing of doughs making for a flatter than desired finished product,” she warned. 

The chemical reaction may also occur prematurely in the package if it it’s exposed to heat and moisture, Ms. Thomas said, resulting in a clumpy leavening system that’s unable to produce enough gas during baking. 

As such, producers should store leavening ingredients in air-tight containers away from moisture and heat. Products should also be kept away from aromatic ingredients to avoid absorbing aromas, Ms. Livvix added. 

Bakers may also incorrectly assume that baking powder, the most common chemical leavening system, is suitable for all applications — which isn’t always the case. 

“When developing the right chemical leavening system, the application may need a more refined ingredient approach, including more specific leavening acids that can help provide a boost via a more controlled release, or improved cell structure, texture or flavor,” she explained.

Formulators must also be wary of switching between leavening ingredients, Mr. Bright cautioned, even those that appear the same. This is because there is no standard of identity across manufacturers on the rate of reaction or solubility of leavening agents. 

“You can have three different leavening baking powders from three different manufacturers that will have three different rates of reaction because they’re bringing in raw materials from different suppliers,” he explained. “So, when a baker switches from one double-acting baking powder to double-acting baking powder that has exactly the same ingredient label, there could be issues.” 

With so many opportunities for error, consistency is critical once the right leavening system is established, from temperature to batch size to bake time. Bakers must also account for the impact of ingredients such as flour, shortening and sugars on the system, Ms. Randall said, ensuring they remain the same batch-to-batch. 

This article is an excerpt from the May 2023 issue of Baking & Snack. To read the entire feature on Chemical Leavening, click here.