Historically, bakery product developers’ main goal when selecting appropriate leaveners for a specific application was simply to attain a specific desired outcome every single time. Consistency mattered. Targeted finished-product attributes for the most part revolved around density, volume, spread, and stack height. The functional strengths of certain leaveners—whether natural or chemical—served as the primary drivers for decision-making.
At the simplest end of the leavening spectrum, homemade crêpes need not much more than eggs and heat in order to trap air bubbles for just the right springy touch of lift. On the other end, commercial baked muffins, especially those that need to go through a process of prebaking or baking, freezing, packing, transporting, thawing, and handling before even making it to an oven to finish or reheat, call for a more complex, often custom mixture of chemical leaveners, including baking soda (sodium bicarbonate), sodium acid pyrophosphate, and monocalcium phosphate, to name a few. These help baked goods achieve and maintain a fluffier texture by timing the gas release perfectly during manufacturing.
In the middle, and in many production situations the most common, are risen breads and batters that require live yeast at least or, as in the case of a true sourdough bread, a mixture of flour and water fermented with both yeast and lactic acid-producing bacteria (lactobacilli). A number of forms of yeast are available, including dry yeast, yeast cakes, and fresh yeast.
Yeast can be instant or active. (“Active” being a bit of a misnomer, as the yeast cells are dormant and need to be “activated” by soaking in a liquid with a food source, usually sugar.) Instant yeast is still a dried product but only needs the moisture in the dough or batter to reanimate it.
Since a primary goal of leavening is to create volume and structure, the most ancient way of doing so has been to let nature take its course. There are helpful microbes all around us, and when they chow down on the simple or complex carbohydrates in a “starter,” they produce carbon dioxide (C02) which leavens a batter or dough. Even certain harmful bacteria, such as Clostridium perfringens, have been used effectively to take advantage of their ability to produce C02.
While true sourdough bread products involve such a starter (ideally, the microorganisms in the sourdough starter are wild strains) some bakers rely on wild airborne yeasts to craft their artisan breads. But such production methods are not always suitable to mass production. Researchers have been able to isolate Lactobacillus strains, such as those found in yogurt, and Pediococcus pentosaceus from kefir in order to improve both volume and moisture content in products.
There are many leavening agents that must be replaced to meet the clean label expectations of consumers. At the forefront of this shift, industry is focusing on the removal of leaveners that contain phosphates in order to offer “no artificial/preservative” claims. It should be noted that phosphate leaveners are considered safe at the levels used in commercially made food products and that, in many cases, shifts in public perception drive accommodation.
While developers research less “controversial” leavening ingredients to substitute and meet clean label standards, to qualify a product as “organic” provides additional challenges as many synthetic and non-synthetic leaveners are simply not permitted for use in organic or even “natural” labeled products.
Synthetic leaveners permitted for use in organic products include: ammonium bicarbonate, calcium phosphates, monocalcium phosphate monohydrate (MCPM), anhydrous monocalcium phosphate (AMCP), dicalcium phosphate dihydrate (DCPD), sodium acid pyrophosphate (SAPP, also known as disodium pyrophosphate), and sodium aluminum phosphate (SAP). Another one, potassium bicarbonate is not currently permitted in organic products, even though it has positive health perception as a low-sodium option.
Ingredient technology can allow for combinations of leavening agents that might not have performed as well in previous formulations due to interfering factors. Microencapsulation is an example of such a technological “tweak” and one manufacturer recently released a microencapsulated leavening agent to deliver a more consistent rise.
Raw sorbic acid (as opposed to its more familiar salts, sodium sorbate, potassium sorbate, and calcium sorbate) has long been used as an anti-microbial for inhibiting bread mold, but when microencapsulated for greater time-release, it can also extend shelf-life and improve dough texture and volume in pan bread by increasing the overall retention of leavening gas during the baking process.
The same manufacturer also offers a microencapsulated salt enrobed in vegetable oil that can be added to a basic dinner roll mix as a leavening helper. It effectively minimizes the baking process to only one stage. R&D results showed that the coating on the salt prevented it from interfering with yeast performance, allowing for optimum leavening. The coating also prevented the salt from tightening flour proteins during mixing, so no additional time was required. Because the active salt was released from the coating during baking, bakers were able to use 30% less salt overall.
Aluminum has been a concern of consumers and appears commonly in many baking powders in the form of sodium aluminum phosphate or sodium aluminum sulfate. It helps develop CO2 bubbles in doughs and batters to make them rise. It also helps create lighter texture in doughs and batters.
Several leavening manufacturers have developed rising agents that are as effective as the aluminum-based ones but without the metal. In fact, one ingredient maker recently released a proprietary enzyme technology for new leavening agents that avoids the need to rely on aluminum. Typically, an aluminum-free baking powder will use sodium bicarbonate, potassium bicarbonate, monocalcium phosphate, or even simply arrowroot and cream of tartar (potassium bitartrate) in place of aluminum.
Arora Food Group, LLC’s TruEats Modern Baking Co. faced challenges in going aluminum-free. “We initially formulated our Ayurvedic bakery mixes with Double acting baking soda as the leavening agent,” says owner Surinder Kumar, PhD. “This type of leavening has the benefit of providing the leavening action in two stages, first when liquid is added to the mix to make the batter, and a second time when the batter is placed in the oven. To ensure a clean label product that did not contain sodium aluminum phosphate, we developed a leavening agent based on baking soda and cream of tartar, both natural components.”
Kumar, and his son and partner Daven, had difficulty at first, with the baked products not as light and fluffy unless the batter was used immediately after preparation. “We developed a process for slowing the reaction of those two main components of the leavening agents,” Kumar explains. “Our new, proprietary process ensures that the baking soda and cream of tartar act slowly when mixed with a liquid to make a batter. This helps prolong the life of the batter such that the batter does not have to be baked immediately as before.”
Research and technology have been uncovering other natural ways to boost the performance of certain leavening agents. For example, researchers at the Universidad Autónoma Metropolitana-Iztapalapa in Mexico investigated using pulque–an alcohol beverage made from fermented agave sap–as a leavening agent in bread.
Because the microbial community within pulque typically includes strains of the common Saccharomyces cerevisiae yeast, leavening functionality was likely. However, other microbes within pulque, such as Zymomonas mobilis, brought surprising advantages, such as increasing loaf volume by up to 50% and disrupting the internal organization of starch granules to decrease moisture diffusivity and slow staling. For consumers with yeast intolerance, pulque or isolated Z. mobilis could be an innovative method for delivering clean-label leavening.
Certain antioxidants also can aid in the leavening process. New catechin rising agents (derived from tea) have been found to not only enhance leavening functionalities, but also deliver antioxidant health properties that many of today’s consumers seek. One manufacturer has even discovered a method for using blackcurrant pomace as a source for such applied catechins.
Enzymes work with leaveners to transform starch into sugars that feed the yeast. Well-fed yeast will improve the rise and final shape of a dough and create a more consistent color in the baked product. Two new, maltogenic amylase enzyme solutions were recently developed to address freshness challenges. The enzymes, when used in the baking process, helped create an improved, longer-lasting softness, and increased moisture and “foldability” for sandwich breads, tortilla wraps, and other baked goods. They meet consumer demand for enhanced freshness while extending refrigerator shelf life to reduce waste.
Steamed and beaten
Technique alone can enhance volume and freshness without the need for chemical leavening agents. Introducing more air into a product—such as through steam, foam production, or the use of whipped proteins such as egg whites or legume liquids—can offer a clean-label solution for leavening certain baked goods.
Because these methods require additional mixing time, and more consistency in terms of labor, researchers have developed a variety of new innovations and isolates to speed up the trapping of air in products with a more consistent texture while still fulfilling the clean label void.
Instead of relying on egg whites to trap air and make meringues, you can also use aquafaba (the soaking liquid from legumes).
Whether CO2 or a combination of oxygen, nitrogen and other trace gases (air), rising and structure can be achieved without anything more complicated than a good beating.
Whipped butter or cream will help add volume to a cake batter, and water heated until it’s a gas–steam, that is–can not only add volume to a dough but firm it up as well. Popovers, croissants, puff pastry, and Asian-style steamed buns are perfect examples.
Formulations relying on steam-rising demand high temperatures, however, typically 400°F or higher. The idea is to get the water to vaporize instantly. Items such as popovers or buns will puff up rapidly. In laminated, high-fat doughs this will also separate the layers and make them flaky.
As more “natural” leavening agents and boosters flood the market, bakery product developers and R&D experts will have more options at their fingertips when it comes to creating consistent, cleaner label products.
Alexia Ciarfella is a food science graduate student and holds both food science and nutritional science degrees from Rutgers University.
Amelia Levin is a Chicago-based food writer, cookbook author, certified chef, and certified holistic nutritionist. A regular contributor to Prepared Foods, she has authored or contributed to nine books and writes for a variety of food industry trade publications. She may be reached at www.amelialevin.com.
Today’s bakers, viewing product quality as a concern that is more than the sum of organoleptic parts, are focusing on aspects such as “clean label” and minimal ingredients. These considerations are driving leavening choices, as well as the need to meeting specific label claim criteria such as “certified organic,” “natural,” non-GMO, and other ways of addressing the clean label trend.
As clean label becomes an increasingly stronger purchase driver, “no additive/preservative” claims are more prevalent in the baked product category to appeal to such consumer demands. Global bakery product launches with “no additives/preservatives” claims have been rising steadily, and now stand at 15% as of July, 2020, according to research group Mintel. In order to make these claims, bakeries must determine which leavening agents consumers perceive as undesirable and either find alternatives or reformulate their recipes.
Non-synthetic leaveners permitted for use in organic products include baking soda (sodium bicarbonate), tartaric acid (derived from fruits such as grapes and citrus), glucono-delta-lactone (GLD), and yeast. The USDA’s National Organic Program should always be consulted to verify acceptability of specific leaveners within organic-labeled products.