With different leavening acids and bases to choose from, chemical leavening solutions are easily customizable. It’s critical that formulators choose ingredients that will respond well or at least not be harmed by freezing and thawing. The main goal here is to delay the reaction, preserving it for later. 

“Choosing the right leavening system depends on the baker’s specific needs; however, we recommend selecting those that contain phosphate — such as sodium aluminum phosphate — as they perform well in frozen doughs and batters,” said Christopher Bohm, senior director of business development, frozen, Corbion. “This helps to delay any gas release that may occur during the mixing portion of the production process and ensures no carbon dioxide is released until baking begins.”

Phosphate-containing systems optimize gas release in the oven, he explained, which ensures desired product volumes.

As formulators consider their options for leavening acids and bases, they should consider the rate of reaction and the amount of gas being released as batter or dough comes together as well as the heat-activated gas re-lease. For optimal results in frozen products, bakers want the majority of the gas release to occur slowly, activated by heat. This emission needs to work in tandem with starch gelatinization in the oven. Bakers can anticipate a product’s starch gelatinization based on the type and amount of flour in the formulation. This helps determine the threshold of gas release the product can handle in the oven before collapsing.

“Starch gelatinization creates the ‘set’ of the baked product, and once that occurs, gas release can disrupt the structure and potentially cause a collapse of the product,” explained Nita Livvix, R&D manager, Clabber Girl.

In muffins, this process is what causes the desirable crack on the top of the muffin. Ms. Livvix recommended dicalcium phosphate as a slow-acting leavening acid for this situation. However, in other applications, this cracked top — or worse — may not be what the baker wants.

“The knowledgeable use of combining leavening acids that react with liquid and heat is necessary to create a leavening system that will release gas optimal for freezing and subsequent baking,” she explained.

Fast-acting acids like organic acids and monocalcium phosphate are available for reaction once they are hydrated, which means they will start reacting during the freezing and thawing process. Slow-acting acids such as sodium aluminum phosphate, dicalcium phosphate dihydrate are heat-activated and therefore not affected by freezing and thawing. 

[Related reading: Pyler says: Chemical leavening for frozen dough 101]

“Bakers must determine the right balance between the fast-acting and slow-acting acids to ensure an acceptable baked product with good volume and texture,” said Mary Thomas, senior R&D manager, Lesaffre Corp.

Another way to slow down the reaction is using a coarser granulation of sodium bicarbonate. Coarse granulations dissolve more slowly than finer particles. Ms. Thomas warned, however, that granulations that are too coarse create an uneven crust color. It’s all about finding the right fit.

Ms. Livvix also recommended examining the amount of bicarbonate, whether sodium or potassium, present in the system. Other acidic ingredients in the formulation can react with bicarbonate, which will leave less bicarbonate for the leavening reaction.

“Adding additional bicarbonate over and above the amount to be neutralized with leavening acids can compensate for reactions occurring with acidic ingredients,” she said.

Encapsulation is another way to protect bicarbonate from being depleted too soon or leavening acids from re-acting prematurely. A fat coating around the acid or bicarbonate prevents it from reacting during mixing or freezing. This fat melts in the oven, starting the reaction.  

This approach works well for those products that need to reserve all of the chemical reaction for the oven. Ap-plications that require a pre-reaction in the mixer aren’t excluded from the benefits of encapsulation, however.

“Often a combination of non-encapsulated material is used along with an encapsulate to facilitate some gas release in the batter, as well as during baking,” Ms. Livvix explained.

This article is an excerpt from the December 2020 issue of Baking & Snack. To read the entire feature on chemical leavening, click here.