Can you substitute cornstarch for baking soda? (how)

In this article, we will answer the question “Can you substitute cornstarch for baking soda?” and discuss what is the difference between cornstarch and baking soda, the uses of cornstarch and baking soda and what are the possible substitutes for baking soda.

Can you substitute cornstarch for baking soda?

No, you cannot substitute cornstarch for baking soda. Cornstarch and baking soda are used for different purposes and have different functions as food ingredients or when added to baking.

While baking soda has a function as a leavening agent, cornstarch acts as a food thickener or as a substitute for wheat flour in gluten-free recipes (1, 2, 3).

What is the difference between cornstarch and baking soda?

The difference between cornstarch and baking soda is that cornstarch is a polysaccharide (carbohydrate) and baking soda, or sodium bicarbonate, is a salt.

Cornstarch is relatively inert and does not react when mixed with other ingredients or when is submitted to heat (with some exceptions, such as acid hydrolysis), while sodium bicarbonate is added to food to generate carbon dioxide under heat, as it reacts with acids present in the food (or dough) (1, 2, 3).

For this reason, cornstarch is used as a thickener agent and sodium bicarbonate is used as a leavening agent. Cornstarch is usually used in higher concentrations, and even as a main ingredient, while sodium bicarbonate is used in small amounts.

What is baking soda?

Baking soda or sodium bicarbonate is a salt with an alkaline characteristic. In the food industry, baking soda can be used to neutralise acids (3). For baking purposes, sodium bicarbonate is added with acid, such as buttermilk because of its reactivity with acidic ingredients.

In the presence of acids and the effect of heat, sodium bicarbonate reacts to generate carbon dioxide, which forms gas bubbles and expands the dough. Due to the prompt reaction, and fast diffusion throughout the dough, it cannot be used for long-fermented doughs, such as bread (3).

What is cornstarch?

Cornstarch is a carbohydrate polymer constituted by two polysaccharide chains: amylose and amylopectin, which have different degrees of branching and length.

The product is obtained from the processing of corn and is widely used not only in the food industry as a food ingredient, but also in the paper, the fuel and the pharma industries (1).

It can be used as a thickener or stabiliser in food products or as an ingredient such as to produce gluten-free products in the place of wheat flour (2).

What are possible substitutes for baking soda?

Baking powder

Baking powder is made up of a mixture of different sodium bicarbonates, an acidic component, such as potassium tartrates or diphosphates and cornstarch.

Different from baking soda, it contains more than one salt and does not require the addition of an acidic ingredient in the dough, as the acidic compound is present in its formulation.

In this way, it reacts completely without leaving any residual off-flavour, which is generally reported when sodium bicarbonate alone is used and degraded thermally without reacting (5).

The use of baking powders in cookie baking is related to a greater height and lower spreading of the dough, in addition to a softer and softer product, when compared to cookies made with sodium bicarbonate or ammonium bicarbonate.

The formation of bubbles is more uniform and better distribution of the air bubbles, improving the quality of the product.

Egg whites

Egg whites can act as a leavening agent, not due to chemical reactions, but because they can physically trap air bubbles when beaten, thus incorporating air into the batter or dough (4).

When egg whites are used as a leavening agent, the liquid added to the dough should be reduced, because of the water naturally present in the egg whites.

Studies showed that using egg whites as a leavening agent resulted in poor quality products when compared to products made with chemical leavenings, such as baking powder because the egg whites have limited capacity to incorporate air into the dough.

However, the height of the dough was greater when using egg whites as leavening than when no leavening agent was used (5).

Conclusion

In this article, we answered the question “Can you substitute cornstarch for baking soda?” and discussed what is the difference between cornstarch and baking soda, what are the uses of cornstarch and baking soda and what are the possible substitutes for baking soda.

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References

1.-

Yu J-K, Moon Y-S. Corn Starch: Quality and Quantity Improvement for Industrial Uses. Plants [Internet] 2021;11(1):92. Available from: http://dx.doi.org/10.3390/plants11010092

3.-

Diez-Sánchez E, Llorca E, Tárrega A, Fiszman S, Hernando I. Changing chemical leavening to improve the structural, textural and sensory properties of functional cakes with blackcurrant pomace. Lwt. 2020 Jun 1;127:109378.

5.-

Canali G, Balestra F, Glicerina V, Pasini F, Caboni MF, Romani S. Influence of different baking powders on physico-chemical, sensory and volatile compounds in biscuits and their impact on textural modifications during soaking. Journal of Food Science and Technology. 2020 Oct;57:3864-73.