The Chemistry of Baking Cookies

chemistry of baking cookiesWant to wow your chemistry teacher? Bring in a batch of chocolate chip cookies. No, it’s not about being the teacher’s pet. It’s about enjoying the tastier side of science. Baking is all about chemistry and if you’re looking for a way to experience it first-hand, the chemistry of baking cookies the best way to go.

“When you’re baking you’re dealing with chemical reactions,” says chemistry tutor and former baker Darren L. “If you understand the chemistry, it gives you an edge.”

Here’s a recipe for chocolate chip cookies in chemistry speak.

In Chemistry Speak
¾ cup sugar Sucrose
¾ cup packed brown sugar Sucrose and flavoring
1 cup butter Fat
1 large egg Albumin, fat and protein
2 ¼ cups all-purpose flour Gluten
1 teaspoon baking soda Sodium bicarbonate (NaHCO3) (base)
½ teaspoon salt NaCl
2 cups semi-sweet chocolate chips Yummy
The Chemistry of Baking Cookies
Preheat oven to 375 degrees
Mix sugar, brown sugar, butter and egg in a large bowl. Only physical changes.
Stir in flour, baking soda, and salt. You add flour late in the process so that you won’t “work” the dough for too long, keeping the gluten complexes small.
Stir in chocolate chips. Yummy!
Drop dough by rounded tablespoonfuls 2 inches apart onto cookie sheet. Size matters. CO2 bubbles form throughout the entire cookie. Only the outside gets hot enough to caramelize.
Bake 8 to 10 minutes or until light brown. The centers will be soft. When the batter heats up, the sucrose (sugar) breaks down into glucose and fructose, forming a polymer chain, giving the cookie its light brown, shiny crust. When sodium bicarbonate (baking soda) heats up, it causes a chemical reaction: 2NaHCO3 ? Na2CO3 + H2O + CO2. The CO2 gas that’s formed makes the “bubbles” in the cookies. NaCl (salt) keeps the bubbles from getting too big by slowing the production of CO2. The fat (butter) keeps the flour from forming an overly extensive network of gluten, giving the cookie a lighter texture. The fat and protein (egg yolk) hold the dough together and the albumin (egg whites) support the bubbles.
Let cool for one minute then remove from cookie sheet and place on wire rack to finish cooling. Cooling allows caramelizing to be completed and allows structure developed by gluten and egg to set.

*This recipe is from

What are some other ways that chemistry happens in the kitchen?

18 Responses to The Chemistry of Baking Cookies

  1. suzie October 13, 2014 at 2:11 PM #

    these cookies sound swell and grand im planning on making them

  2. Somama October 13, 2014 at 1:58 PM #

    I had to use this in my middle school class, (Duluth)

    • Aidan N October 19, 2017 at 8:02 PM #

      me to……. :/

  3. riley September 17, 2014 at 10:49 AM #

    my teacher wanted me to use this website

    • Luke September 18, 2014 at 2:36 PM #

      my teacher wants me to use it to!!!

      • e man December 8, 2014 at 10:58 AM #

        ME TOO!!!!!! This is uncanny!

      • 666 December 8, 2014 at 10:59 AM #


    • Ryan Pratt March 29, 2017 at 9:40 AM #

      Omg me too!

    • Ryan Pratt March 29, 2017 at 9:41 AM #

      Omg me too! 🙂 🙂 🙂

      • Nick November 10, 2017 at 8:56 AM #

        Yeah it is not a big deal but my teacher too.

      • Lol November 28, 2017 at 9:23 AM #


  4. Miatta January 15, 2013 at 8:58 PM #

    NaHCO3 + CH3COOH —> NaC2H3O2 + H2O + CO2

  5. Kylee Walker December 6, 2012 at 10:07 AM #

    This was great! I feeling strong about this project! Thanks so much for my easy A!! You rock!! And make GREAT cookie! YUMMM!!!

  6. valerie October 23, 2012 at 9:33 PM #

    so im doing a middle skool experiment about baking and the science of it. im seeing if the different types of flour or flour substitutes such as corn starch or rice flour affect the baking time of the actual cake, this broken down explanation of whats happening in the batter is very helpful so thank u

    • riley September 17, 2014 at 10:52 AM #


  7. anne October 21, 2012 at 9:45 PM #

    is the chemical reaction 2NaHCO3 ? Na2CO3 + H2O + CO2 right? where did the -> sign go?

    • Miatta January 15, 2013 at 8:58 PM #

      NaHCO3 + CH3COOH —> NaC2H3O2 + H2O + CO2

      • shann March 2, 2016 at 5:32 PM #

        hello peeps it sounds delicious but it quite doesnt look like it lol!

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