Molecular Gastronomy

The chemistry behind baking


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What is in Cake Mix?

To my fellow bakers out there who cannot even manage to whip up a brownie mix without producing one that resembles a pile of muck, I feel your pain. Our lack of efficiency with an oven, therefore, should justify our clandestine storage of “Betty Crocker” baking mixes near the back of the cupboard. While aggregating the cake mix with the necessary adjuncts (i.e. water/buttermilk, eggs, vegetable oil, etc.) has become routine for us inept bakers, have you ever considered what exactly composes such cake mixes? We are, after all, only familiar with the delectable desserts that our ovens manage to conjure from solely water, eggs, oil, and a mysterious powder mixture, and rarely question the label on the mix box that reads, “Make decadent, bakery-quality cakes in your home oven!”

The components of and chemistry behind packaged cake mix are far from complex. Among the cake mix ingredients include, and are not limited to, flour, sugar, leavening, shortening, emulsifiers, colorings, and flavorings. Below you will find the purpose of and chemistry behind each of these components:

Flour: When combined with water, the mixture forms gluten, a complex protein that allows for the formation and maintenance of gas bubbles, which provides the mix with its malleability.

Sugar: In addition to sweetening baked goods, sugar allows baked treats to maintain their moisture, thus increasing shelf life. Sugar also influences yeast growth; while a sufficient quantity of sugar is necessary to instigate yeast growth, superfluous sugar may render the yeast growth process inactive.

HOUSEHOLD SUGAR (SUCROSE)

Leavening:  What are the two most common leavening agents? Both baking soda and baking powder are used for cake batters to rise. Simply put, leaveners raise baked goods by expanding the gas bubbles produced by the creaming of ingredients. Baking powder constitutes baking soda, at least one acid salt, and cornstarch to take in all moisture and prevent a reaction from initiating until another liquid is poured in with the batter. When used in cake batter, baking powder reacts in two stages, with the first occurring when the powder is added to moistened batter and an acid salt reacts with the baking soda to form carbon dioxide gas. Once the batter is in the oven, the imposed heat forces the gas bubbles to enlarge and the batter to rise. On the other hand, baking soda, or sodium bicarbonate, leaves most of the leavening to baking powder when both are required in a recipe.

BAKING SODA (SODIUM BICARBONATE)

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Shortening: Shortenings include the fats or oils of vegetable or animal origin included in baked goods to create a soft, smooth crumb and tenderness. Most shortenings are quite consistent in chemical composition and consist of the following in varying ratios:

  • STEARIN—a naturally-occurring, hard fat of animal origin
  • PALMITIN—a fat, secured from both animal and vegetable sources
  • OLEIN—an oil secured from both animal and vegetable sources
  • LINOLIN—an oil present in cottonseed oil

 

Emulsifier: Emulsifiers fix the fats and liquids together and contribute to the moistness of baked goods. The most common of emulsifiers is soy lecithin.

Check back later for more about the chemistry of baking! (:

Author: Carrie Xu

Sources:

http://www.ivillage.com/whats-cake-mix/3-a-57713

http://www.joyofbaking.com/bakingsoda.html

http://abrfaq.info/treatise/196

http://www.essortment.com/understanding-baking-basics-flour-sugar-41122.html

http://www.detergentsandsoaps.com/emulsifiers.html

http://students.cis.uab.edu/ekellis/BakingSodaVolcano.html

http://chemistry.about.com/od/factsstructures/ig/Chemical-Structures—S/Sodium-Bicarbonate.htm


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Caramelization

Caramelization is the process of sugars breaking down. This is often used as a general term to describe the Maillard Reaction. However, these two browning processes are very different. The Maillard Reaction is the break down of sugars in the presence of proteins, therefore it contributes to the browning and flavoring of bread crusts.

Simply speaking, caramelization is the process of removal of water from a sugar (such as sucrose or glucose) followed by isomerization and polymerisation. In reality the caramelization process is a complex series of chemical reactions, which is still poorly understood.

Below is a table listing the Stages of Caramelization.

Caramelization Stages Table

Caramelization is sensitive to its chemical surroundings. For example, the level of acidity (pH) must be controlled or else the reaction rate may be altered. Caramelization usually occurs slowest when when the acidity is near neutral (pH of 7), and it is accelerated under both acidic and alkaline conditions.The different stages of caramel production all have distinct names based on the characteristics of the product. “Thread” indicates the fact that sugar can be spun into soft or hard threads, “ball” indicates that sugar can easily be molded into a proper shape, and “crack” indicates that the sugar will hard after cooling (and crack when it is broken).

The animated video below expands more on The Maillard Reaction and Caramelization:

Things to keep in mind while watching the video:

  • What is the difference between Enzymatic and Non-Enzymatic Browning Reactions?
  • How does temperature affect the Maillard Reaction?
  • What are some desirable and undesirable affects for all three reactions?
  • What is the difference between the Maillard Reaction and Caramelization?
  • Which reactions occur in baked goods?

Look forward to our future posts discussing the chemistry of baking!

Author: Jamie Lee

Sources: