chocolate-chip-cookie

 

 

 

 

 

 

 

 

 

So, you like to bake –say chocolate chip cookies–but you’re not a fan of science?

I’ve got news for you! Bakers are mad scientists. Think about it. You first gather your materials and make a mixture—dough. You put some energy to it—thermal energy—heat—and that sets off a bunch of chemical reactions. You transform one thing—dough—into another–cookies

 

 

Let’s take a look at the chocolate chip cookie timeline of chemical reactions.

cooking science

When you bake a cookie, here’s what’s going on, step-by-step.

  • 92 °–the spread: As the cookie dough starts to heat up, the butter inside it melts. The cookie dough begins to turn more liquid and gradually spreads out. As the cookie spreads, the edges thin out. This, coupled with the fact that they are fully exposed to the heat of the oven and are constantly reaching hotter areas of the baking pan, causes them to begin to set long before the center of the cookie does.
  • 136°–Goodbye salmonella–Salmonella bacteria can survive for weeks in eggs. This can make you really sick. This is why you shouldn’t eat cookie dough. 136° is too hot for them and they die.
  • 144° Egg proteins begin to change. In a raw egg, proteins look like coiled up balls of string. As they get heated they unwind and then get tangled up all together This is how eggs go from runny to solid when they get heated. Which is cool because most things turn from solid to liquid when they get heated, right?
  • 212°–The rise: The water in the dough turns into steam at 212°F. The cookie starts to rise as the vapors push through the dough. Eventually, the baking soda or powder starts to react with the acids in the brown sugar and break down into carbon dioxide gas, which raise up the cookie farther. All these gases leave little holes in the maturing cookie, which makes it light and flaky.
  • 310° –The tasty reaction—The Maillard reaction happens when sugars and proteins break down and rearrange themselves. The molecules are ringlike in shape and they reflect a certain light—brownish light—this is what makes toast and other things toasty brown. It produces all sorts of toasty, nutty and even savory flavors.  
  • 356°–caramelization–As sugars in the dough break down, they transform from clear, odorless crystals into a brown, fragrant liquid that’s overflowing with aromas and tastes — think butterscotch, sweet rum and popcorn.
  • The cookie cools. Once it comes out of the oven, the process isn’t over yet. Remember that liquefied sugar? Well as the cookie cools, that liquid sugar hardens up, which can give the cookie an extra-crisp, toffee-like texture around the edges. Meanwhile, the air inside cools, which causes the cookie to deflate slightly.

chemical change

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

How Cookies Crumble

Most chocolate chip cookie recipes have the same basic ingredients and technique: butter and sugar (a mix of white and brown) are creamed together with a touch of vanilla until fluffy, eggs are beaten in one at a time, followed by flour, salt, and some sort of chemical leavening (baking soda, baking powder, or a bit of both). The mixture is combined just until it comes together, then spooned onto a baking sheet and baked.

What kind of cookie do YOU want?

Engineering the perfect cookie for you!

You like chewy?

You like cakey? You like crispy?

No problem.

 

It’s all about the variables.

 cookie science 2

 

 

 

 

 

 

Chewy

  • 2 1/4 cups bread flour
  • 1/2 teaspoon baking soda
  • 1 cup (2 sticks) unsalted butter, room temperature
  • 1/2 cup granulated sugar
  • 1 cup packed light-brown sugar
  • 1 teaspoon saltchewy
  • 2 teaspoons pure vanilla extract
  • 2 large eggs
  • 2 cups (about 12 ounces) semisweet and/or milk chocolate chips

 

  1. Preheat oven to 350 degrees. In a small bowl, whisk together the flour and baking soda; set aside. In the bowl of an electric mixer fitted with the paddle attachment, combine the butter with both sugars; beat on medium speed until light and fluffy. Reduce speed to low; add the salt, vanilla, and eggs. Beat until well mixed, about 1 minute. Add flour mixture; mix until just combined. Stir in the chocolate chips.
  2. Drop heaping tablespoon-size balls of dough about 2 inches apart on baking sheets lined with parchment paper.
  3. Bake until cookies are golden around the edges, but still soft in the center, 8 to 10 minutes. Remove from oven, and let cool on baking sheet 1 to 2 minutes. Transfer to a wire rack, and let cool completely. Store cookies in an airtight container at room temperature up to 1 week.

 

Cakey

cakey

  • 2 1/4 cups cake flour
  • 1/2 teaspoon baking soda
  • 1 -3/4 sticks unsalted butter, room temperature
  • 3/4 cup granulated sugar
  • 1/4 cup packed light-brown sugar
  • 1 teaspoon salt
  • 2 teaspoons pure vanilla extract
  • 2 large eggs
  • 2 cups (about 12 ounces) semisweet and/or milk chocolate chips
  1. Preheat oven to 350 degrees. In a small bowl, whisk together the flour and baking soda; set aside. In the bowl of an electric mixer fitted with the paddle attachment, combine the butter with both sugars; beat on medium speed until light and fluffy. Reduce speed to low; add the salt, vanilla, and eggs. Beat until well mixed, about 1 minute. Add flour mixture; mix until just combined. Stir in the chocolate chips.
  2. Drop heaping tablespoon-size balls of dough about 2 inches apart on baking sheets lined with parchment paper.
  3. Bake until cookies are golden around the edges, but still soft in the center, 8 to 10 minutes. Remove from oven, and let cool on baking sheet 1 to 2 minutes. Transfer to a wire rack, and let cool completely. Store cookies in an airtight container at room temperature up to 1 week.

 

 

Crispy

  • 2 1/4 cups all-purpose flour
  • 1/2 teaspoon baking sodachocolate-chip-cookie
  • 1 1/4 cups (2 1/2 sticks) unsalted butter, room temperature
  • 1 1/4 cups granulated sugar
  • 3/4 cup packed light-brown sugar
  • 1 teaspoon salt
  • 2 teaspoons pure vanilla extract
  • 2 large eggs
  • 2 cups (about 12 ounces) semisweet and/or milk chocolate chips
  1. Preheat oven to 350 degrees. In a small bowl, whisk together the flour and baking soda; set aside. In the bowl of an electric mixer fitted with the paddle attachment, combine the butter with both sugars; beat on medium speed until light and fluffy. Reduce speed to low; add the salt, vanilla, and eggs. Beat until well mixed, about 1 minute. Add flour mixture; mix until just combined. Stir in the chocolate chips.
  2. Drop heaping tablespoon-size balls of dough about 2 inches apart on baking sheets lined with parchment paper.
  3. Bake until cookies are golden around the edges, but still soft in the center, 8 to 10 minutes. Remove from oven, and let cool on baking sheet 1 to 2 minutes. Transfer to a wire rack, and let cool completely. Store cookies in an airtight container at room temperature up to 1 week.

 

Try changing it up. How do your cookies change when you melt butter? How do they change if you add less flour? What happens if you add a bit of corn syrup in with the sugar?

What if you use gluten free flour?

 

As a good scientist—you have to repeat your experiments many times!