Science and Cooking: From Haute Cuisine to Soft Matter Science - Baking

As I posted in a previous blog entry, I've enrolled in an on-line course about the relationship between science and cooking.

Here's what went down week 9 .

• To coincide with all the holiday baking going on, this week's lesson explores the basic physics and chemistry involved in baking. Joanne Chang is this week's celebrity instructor.
• Baking involves a lot of the topics already covered in the course. Understanding these concepts won't make you a master baker, but hopefully, it will help you make better sense of the recipes you're using: 
• Elasticity -  the properties of gluten; the elastic network that occurs in proteins, starches, and sugars.
• Viscosity - any time something expands and rises, it involves the flowing of molecules by each other; without it, your breads wouldn't rise, and your cakes and cookies wouldn't expand.   
• Emulsions - baked goods tend to be made of bubbles that are packed together, and those bubbles are the result of gas expansion that occurs during baking.
• Heat transfer - obeys the laws of diffusion.
• Joanne Chang shows us some of the science behind making a birthday cake and a flaky pie dough:
  
  
• Though a birthday cake would work for Christmas baking (think about it), here's the recipe for another cake used in this lesson to try over the holidays, a Coca Cola cake:
  

  Ingredients

  1 cup cola
  1/2 cup buttermilk
  1 cup butter, softened
  1 3/4 cups sugar
  2 large eggs, lightly beaten
  2 teaspoons vanilla extract
  2 cups all-purpose flour
  1/4 cup cocoa
  1 teaspoon baking soda
  1 1/2 cups miniature marshmallows
  3/4 cup chopped pecans, toasted (optional garnish)

  
  
  1. Combine the cola and the buttermilk in a bowl, then set the mixture aside.
  2. Beat the butter at a low speed with an electric mixer until creamy. Gradually add sugar; beat until blended. Add the egg and vanilla, and again beat at low speed until blended.
  3. Combine the flour and cocoa to the cola mixture. Add to the butter mixture alternately with the cola mixture; begin and end with the flour mixture. Beat at low speed just until blended.
  4. Stir in the marshmallows. Pour the batter into a greased and floured pan. Bake at 350° for 30 to 35 minutes. Now is the time to make your frosting.

  1/2 cup butter
  1/3 cup cola
  3 tablespoons cocoa
  1 (16-ounce) package powdered sugar
  1 tablespoon vanilla extract
  2 teaspoons vanilla extract

  5. Combine the butter, cola, and cocoa and bring it to a boil in a large saucepan over medium heat, stirring until the butter melts. Remove from heat, and whisk in the sugar and vanilla.
  6. Remove the cake from the oven, and allow it cool 10 minutes. Pour the frosting over the warm cake. Garnish with the pecans, if desired.