Ahh, the smell of freshly baked chocolate chip cookies, the smell of my childhood, and my favorite smell to date. What could possibly be better than the smell of chocolate chip cookies? The taste of course! The melting chocolate, gooey center and crisp crunch of a chocolate cookie is second to none but what makes a chocolate chip cookie so tasty anyway?
The purpose of the cookie is to be a sweet treat at the end of the meal. Like many other desserts, chocolate chip cookies rely on flour to create base layer. Different ratios of flour to water will produce vastly different styles of cookies. A high ratio of water to flour often dilutes gluten proteins and produces either a soft texture or a crispy texture depending on how much moisture is lost when baking. Flour also determines if the cookie will hold its shape after baking. In order for a cookie to hold its shape, it needs a high flour content to stabilize the cookie structure.
Like flour, sugar is a key component in the baking of cookies. When sugar is whisked with the fat, the sugar produces air bubbles that lighten the texture of the cookie and give the cookie a fluffy texture with every bite. Sugar also competes with the flour for the minimal amount of water present in the cookies. As the temperature rises during the baking process, more sugar dissolves and the outside of the dough begins to dry out, spread, and harden to give the cookies a distinct crunch. Along with structure, sugar also contributes to the flavor found in cookies. When heated to 50°C (100°F), the Maillard reaction commences and at 165°C (330°F) the sugar caramelizes and provides additional browning. The Maillard reaction breaks down carbohydrate molecules to produce molecules that create nutty and coffee flavors. Additionally, carmelization will further break down sucrose molecules to produce molecules that give the cookies a toasty or savory aroma.
The fat found in butter helps provide texture and flavor to the cookie. In fact, butter and eggs are often the only source of liquid for a cookie. When the butter melts, the liquefied butterfat causes the cookie to spread out and flatten in the oven. As the temperature continues to increase, the water partially gelates the starch molecules and further causes the cookies to expand.
When salt is added to the dough, it strengthens the proteins in the dough and makes the cookies chewier. It also enhances our body’s ability to sense sweet flavors and improves the overall taste of the cookie.
One final key component of a cookie is baking soda. Baking soda reacts with the acidic molasses in the brown sugar to produce CO2 gas, which causes the dough to rise. The carbon dioxide tenderizes the cookies and gives them an airy and fluffy texture. When moistened and heated, baking soda can be used to neutralize acid ingredients found in the dough, such as molasses, vanilla extract and butter. The neutralization of acids encourages the Maillard reaction to take place, thus adding additional flavors to the cookie.
The Nestle® Toll House recipe undoubtedly produces excellent chocolate chip cookies but we wanted to see what would happen if we varied the recipe slightly. We made cookies with 12 different variations on the Nestle® Toll House recipe that I have recorded in the table below. The recipe we used was the following and ingredients were combined according to the Nestle® Toll House recipe.
- 3 tablespoons sugar
- 3 tablespoons brown sugar
- ¼ cup butter
- ½ egg
- dash of vanilla
- ½ cup + 1 tablespoon flour
- ¼ teaspoon salt
- ¼ teaspoon baking soda
|Modifications made to cookie||Taste of cookie||Code|
|No change to recipe||Caramel notes, buttery, intense chocolate bites, soft||1|
|1/2 cup and 1 tablespoon gluten free flour to replace all purpose flour||Less caramel flavor, lack of wheaty taste, intense chocolate bites, soft||2|
|1/2 cup and 1 tablespoon potato starch to replace all purpose flour||Bitter, lack of caramel notes, less chocolate flavor, crisp||3|
|1/2 cup butter to replace 1/4 cup of butter||Extra buttery, extra caramel notes, intense chocolate bites, crisp||4|
|1/2 cup and 1 tablespoon whole wheat flour to replace all purpose flour||Distinct taste of whole wheat, buttery, intense chocolate bites, soft||5|
|6 tablespoons of brown sugar, no table sugar||Extra caramel notes, distinct molasses taste, intense chocolate bites, soft||6|
|1/4 cup melted butter to replace softened butter||Caramel notes, buttery, intense chocolate bites, crumbled easily, crisp||7|
|1/4 cup of olive oil to replace butter||Distinct olive oil notes, intense chocolate bites, caramel notes, soft,||8|
|1/4 cup applesauce to replace 1/2 egg||Hint of cinnamon flavor, intense chocolate bites, less caramel, soft||9|
|1/4 egg and 1 tablespoon vinegar to replace egg||Slightly acidic, slightly less caramel, intense chocolate bites, soft||10|
|1/2 cup and 1 tablespoon bread flour to replace all purpose flour||Caramel notes, buttery, intense chocolate bites, soft||11|
|1/4 teaspoon baking powder to replace baking soda||Caramel notes, buttery, intense chocolate bites, crisp||12|
We also looked for differences in color, shape, and consistency of the cookies.
Here we see our first batch of cookies! Mmm, just looking back on this picture makes me hungry. From top to bottom we have cookies 5, 2, and 1. Cookies 1 and 5 look remarkably similar. Of course, 1 appears to be a darker brown color, likely due to additional bran, germ and endosperm that is found in the whole wheat flour. 2 appears to have spread out more than cookies 5 and 1. This is likely due to the fact that 2 was baked with gluten free flour. Without the massive gluten proteins and their strong intermolecular forces, the cookies can spread out more easily.
From top to bottom, we have groups 1, 7, and 12. All of the cookies in this batch appear to have the same shape. However, cookies in group 7 are much more cracked and crumble more easily.
From top to bottom we have 9, 11 and 6. Surprisingly, all of the cookies look remarkably similar. The only way to tell them apart is by looking at the pencil labeling on the parchment paper. They all have similar color and consistency but 9 does appear to have additional depth. However, it is distinctly possible that the cookies in group 9 had a greater amount of batter before being placed into the oven. Although they all look similar, they tasted very different (see table above).
From top to bottom we have 9, 8, and 4. Well, the cookies in this set certainly look different! The cookies in group 9 and 4 appear to have much more browning, likely due to the fact that they were baked with butter and 8 was baked with olive oil. Unlike butter, olive oil does not contain carbohydrates. Consequently, olive oil will not undergo the Maillard reaction. Cookies in groups 8 and 9 have much more depth than the cookies in-group 4 because they didn’t have nearly as much liquid in their batters. The flatness of the cookies in group 4 gave them a the best crunch and they were my personal favorite.
Now for our final set of cookies and the wildcards of the bunch. From top to bottom we have 10 and 3. Our cookies in group 10 did not appear to undergo much Maillard reaction. This is likely due to the acid in the vinegar greatly reducing the amount of Maillard reaction taking place. Perhaps with more baking soda we could have had a greater amount of Maillard reaction take place. As for cookies in group 10, they were probably the least tasty cookies out of any group. Potato starch dissolves at lower temperatures than gluten proteins, which prevented the cookies baked with potato starch from gelating. This caused the cookies to become very thin and crispy (see picture below to see what happened during the baking process). Since the batter spread so thin, it burnt on the edges and had a bitter flavor.
It was a wonderful and tasty day baking cookies. If you have ever experimented with your favorite cookie recipe, let us know. We would love to see what modifications you made and the changes that happened during the baking process. Happy baking!