AN EXPLORATION OF THE CHEMISTRY BEHIND POUND CAKE
Editor’s note: In this exploration of Pound Cake, Zamien Allard (‘19) discusses the chemistry behind the light and flavorful texture.
When you look at the traditional pound cake, what probably comes to mind is a heavy, dense texture that may or may not be enjoyable for you. However, if you were to look at the microscopic aspect of baking like Alton Brown, the scientist-chef televised on the Food Network, you can produce a favorable chemical reaction which would result in an airier and lighter texture. A simple recipe for a pound cake calls for a pound of eggs, flour, sugar, butter and to add flavor, a teaspoon of vanilla extract. By mixing these fundamental ingredients in a select order, and tweaking parts of the instructions, you can create a lighter and more flavorful texture.
The first step in the recipe is to mix a pound of butter and sugar for one minute at medium speed . To ensure the best results, use room temperature butter as the fat in the butter would be easily distributed throughout the batter and would create a more homogeneous (mixable) batter (Huff, 2015). In addition to the temperature of the butter, Alton Brown (2009) has recommended that you use European butter as opposed to American butter. This is because when you cream butter and sugar together, the sugar granules cut into the butter’s fat cells causing aeration (forcing air into a substance) which creates a lighter texture (Huff, 2015). European butter has a higher concentration of fat than American butter which means that more air is allowed into the batter (Huff, 2015). By simply tweaking the temperature and the type of butter, you can create a more favorable foundation for your cake.
Your next step in the recipe is too crack a pound of room temperature eggs (roughly nine large eggs) and mix them in with the creamed butter and sugar. The key to a better recipe is mix each egg one at a time at the slowest speed setting with ample time in between each egg instead of dumping them in all at once. This is to ensure an emulsion of fat and liquid in the mixture (Weisenthal 2011). An emulsion is the suspension of small globules (a round substance) of one liquid in a second liquid with which the first will not mix, such as oil and vinegar or in this case eggs and the batter. This is why we slowly add eggs to the butter mixture, one at a time: to make it easier to disperse the liquid, and promote even suspension of liquid in fat. Ensuring that all of the ingredients are around 70 degrees Fahrenheit will also help them combine more easily and smoothly by promoting aeration in the egg whites and preventing curdling. Again forcing aeration and a good emulsion will ensure that your end result is a lighter texture.
The third and final step in the mixing process is to add the flour. Traditionally, you would use all-purpose flour but for best results you would want to use bleached cake flour (Brown, 2009). The difference between them that matters to us is the protein content in the flour. All-purpose flour has 14% protein whereas cake flour has 7% protein (Christensen, 2009, para. 5). Protein content/concentration is directly related to how much gluten can be formed from the mixing of the flour using that particular flour. Gluten—created when natural wheat flour protein is mixed with water— helps create structure and determine texture in your final baked good (Christensen, 2009, para. 3). Therefore, the type of flour with the least protein content will create less gluten, which will result in a lighter texture for your batter.
The final step to creating a successful science-knowledge infused cake is to bake your batter. Most recipes suggest that you bake for a certain amount of time but once again Alton Brown suggests an alternative that will greatly improve your cake. Brown states that temperature is a better indicator of how well a cake is baked over time. This is because as the batter heats up, all the microscopic pockets of air that were aerated into the cake expand, which results in the rising of the cake (Brown, 2009). At around 140ºC, water vapor forms and moisture begins to leave the cake and around 180ºC the protein in the batter coagulates (a fluid solidifying) around the air pockets creating a lattice like structure (the shape of the cake) and the starch in the flour gelates (solidifying) (Brown, 2009). When the cake reaches 200ºC enough moisture has been driven out that the sugar near the surface can caramelize or “brown” and the protein can begin the Maillard reaction (Brown, 2009). The Maillard reaction is “the reaction between a nitrogen containing molecule [amino acids in food found in proteins] and a sugar [glucose]” (The Maillard Reaction, 2011). Essentially, when heat is applied to the amino acids and protein, they form a molecule which breaks down eight different times with the final “stage” resulting in a darker color and desirable flavor of food (The Maillard Reaction, 2011). Finally, when your cake reaches 210°C and completes the maillard reaction, your cake is ready to be taken out of the oven. Thus, by following a simple recipe and tweaking the mixing time, type and temperature of the ingredients you can easily create a delicious tasting cake with the help of science.
Bibliography
Brown, A. (Producer). (n.d.). A Pound of Cake [Video file]. In A Pound of Cake. Retrieved December 8, 2016, from
http://www.foodnetwork.com/shows/good-eats/good-eats-full-episodes-video-gallery.html
Christensen, E. (2009). What's the Difference? Cake Flour, Pastry Flour, All-Purpose Flour, and Bread Flour. Retrieved December 08, 2016, from http://www.thekitchn.com/whats-the-difference-cake-flou-74565
Huff, T. (2015). Baking School Day 6: All About Butter and Baking - The Kitchn's Baking School. Retrieved December 08, 2016, from http://www.thekitchn.com/baking-school-day-6-all-about-butter-and-baking-222484
U. (2011, September 25). The Maillard Reaction. Retrieved January 08, 2017, from http://sciencegeist.net/the-maillard-reaction/
Weisenthal, L. (2011). Sweet Technique: Adding Eggs to Cake Batter. Retrieved December 08, 2016 from http://sweets.seriouseats.com/2011/08/sweet-technique-mixing-cake-batter.html
The first step in the recipe is to mix a pound of butter and sugar for one minute at medium speed . To ensure the best results, use room temperature butter as the fat in the butter would be easily distributed throughout the batter and would create a more homogeneous (mixable) batter (Huff, 2015). In addition to the temperature of the butter, Alton Brown (2009) has recommended that you use European butter as opposed to American butter. This is because when you cream butter and sugar together, the sugar granules cut into the butter’s fat cells causing aeration (forcing air into a substance) which creates a lighter texture (Huff, 2015). European butter has a higher concentration of fat than American butter which means that more air is allowed into the batter (Huff, 2015). By simply tweaking the temperature and the type of butter, you can create a more favorable foundation for your cake.
Your next step in the recipe is too crack a pound of room temperature eggs (roughly nine large eggs) and mix them in with the creamed butter and sugar. The key to a better recipe is mix each egg one at a time at the slowest speed setting with ample time in between each egg instead of dumping them in all at once. This is to ensure an emulsion of fat and liquid in the mixture (Weisenthal 2011). An emulsion is the suspension of small globules (a round substance) of one liquid in a second liquid with which the first will not mix, such as oil and vinegar or in this case eggs and the batter. This is why we slowly add eggs to the butter mixture, one at a time: to make it easier to disperse the liquid, and promote even suspension of liquid in fat. Ensuring that all of the ingredients are around 70 degrees Fahrenheit will also help them combine more easily and smoothly by promoting aeration in the egg whites and preventing curdling. Again forcing aeration and a good emulsion will ensure that your end result is a lighter texture.
The third and final step in the mixing process is to add the flour. Traditionally, you would use all-purpose flour but for best results you would want to use bleached cake flour (Brown, 2009). The difference between them that matters to us is the protein content in the flour. All-purpose flour has 14% protein whereas cake flour has 7% protein (Christensen, 2009, para. 5). Protein content/concentration is directly related to how much gluten can be formed from the mixing of the flour using that particular flour. Gluten—created when natural wheat flour protein is mixed with water— helps create structure and determine texture in your final baked good (Christensen, 2009, para. 3). Therefore, the type of flour with the least protein content will create less gluten, which will result in a lighter texture for your batter.
The final step to creating a successful science-knowledge infused cake is to bake your batter. Most recipes suggest that you bake for a certain amount of time but once again Alton Brown suggests an alternative that will greatly improve your cake. Brown states that temperature is a better indicator of how well a cake is baked over time. This is because as the batter heats up, all the microscopic pockets of air that were aerated into the cake expand, which results in the rising of the cake (Brown, 2009). At around 140ºC, water vapor forms and moisture begins to leave the cake and around 180ºC the protein in the batter coagulates (a fluid solidifying) around the air pockets creating a lattice like structure (the shape of the cake) and the starch in the flour gelates (solidifying) (Brown, 2009). When the cake reaches 200ºC enough moisture has been driven out that the sugar near the surface can caramelize or “brown” and the protein can begin the Maillard reaction (Brown, 2009). The Maillard reaction is “the reaction between a nitrogen containing molecule [amino acids in food found in proteins] and a sugar [glucose]” (The Maillard Reaction, 2011). Essentially, when heat is applied to the amino acids and protein, they form a molecule which breaks down eight different times with the final “stage” resulting in a darker color and desirable flavor of food (The Maillard Reaction, 2011). Finally, when your cake reaches 210°C and completes the maillard reaction, your cake is ready to be taken out of the oven. Thus, by following a simple recipe and tweaking the mixing time, type and temperature of the ingredients you can easily create a delicious tasting cake with the help of science.
Bibliography
Brown, A. (Producer). (n.d.). A Pound of Cake [Video file]. In A Pound of Cake. Retrieved December 8, 2016, from
http://www.foodnetwork.com/shows/good-eats/good-eats-full-episodes-video-gallery.html
Christensen, E. (2009). What's the Difference? Cake Flour, Pastry Flour, All-Purpose Flour, and Bread Flour. Retrieved December 08, 2016, from http://www.thekitchn.com/whats-the-difference-cake-flou-74565
Huff, T. (2015). Baking School Day 6: All About Butter and Baking - The Kitchn's Baking School. Retrieved December 08, 2016, from http://www.thekitchn.com/baking-school-day-6-all-about-butter-and-baking-222484
U. (2011, September 25). The Maillard Reaction. Retrieved January 08, 2017, from http://sciencegeist.net/the-maillard-reaction/
Weisenthal, L. (2011). Sweet Technique: Adding Eggs to Cake Batter. Retrieved December 08, 2016 from http://sweets.seriouseats.com/2011/08/sweet-technique-mixing-cake-batter.html
