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Anyone Can Be a Kitchen Scientist

If anyone can cook, then anyone can do science! (Photo credit: Pixar)

If anyone can cook, then anyone can do science! (Photo credit: Pixar)

“Anyone can cook!” declared Chef Auguste Gusteau in the classic animated film Ratatouille. We’ll go a step further: with a little cooking know-how and access to a kitchen anyone can do science. Each spring the students of the Science & Food undergraduate course prove us right as they research and experiment their way toward apple pie enlightenment.

But you don’t have to be a student in our course to be a savvy kitchen scientist. One of our younger readers, Vincent, recently won his local seventh grade science fair by carefully crafting and conducting his own kitchen experiment. By baking cookies with different temperatures of light (reduced fat) butter, Vincent determined that frozen butter creates a chewier cookie than melted butter. His scientifically proven chewy chocolate chip cookie recipe appears at the end of the article.

Vincent’s project is a great example of a successful kitchen experiment. For those of you who are avid kitchen experimenters or are thinking of dipping a toe into the world of kitchen science, we’ve summarized the key features of Vincent’s project that will help make any (kitchen) science experiment a success.

Vincent’s winning science fair project.

Vincent’s winning science fair project.

A close-up of Vincent’s project. Note the number of cookies baked for each butter condition.

A close-up of Vincent’s project. Note the number of cookies baked for each butter condition.

Keys to a successful (kitchen) experiment

A questionScientific research has to start somewhere, and it almost always starts with a thought-provoking question. Why is the sky blue? Why do apples fall from trees? In this case Vincent wanted to know how the temperature of butter affects the chewiness of chocolate chip cookies.

A testable hypothesis – Once researchers have a question in mind, they need to come up with a testable hypothesis. The key word here is testable. Having a testable hypothesis guides researchers as they design effective experimental procedures. Based on a bit of background research and a dash of reasoning, Vincent hypothesized that cookie chewiness would be directly proportional to the temperature of the butter (hotter butter = chewier cookie). Vincent knew he could directly test his hypothesis by baking cookies with different butter temperatures and having a panel of tasters rate the chewiness of each cookie.

A carefully controlled experiment – When designing an experiment, it’s crucial to only change one variable, or component, at a time. Vincent was careful to only test one factor—butter temperature—and keep everything else in the experiment constant.

A large enough sample sizeOnce you’ve perfected your experimental design, repeat, repeat, repeat! Mistakes happen. And even the most thoughtfully executed experiments can go haywire because of factors beyond our control. Ovens have hot spots. Humidity can change the moisture of dough. To help avoid these potential pitfalls, Vincent made eight cookies at each butter temperature and had five different taste-testers rate the cookies.

A thoughtful analysis of the results – At the end of it all, what good is a bunch of data if it doesn’t actually mean anything useful? Based on his taste test, Vincent found that frozen butter produced the chewiest cookies, the exact opposite of his hypothesis! Like a true scientist, Vincent discounted his original hypothesis and offered up some pretty insightful ideas to explain his observations:

“The cookies with melted light butter were the least chewy, almost crunchy. I think this happened because, since there was more moisture in the batter with the melted butter, the cookies spread out more and got flat, exposing more surface area. This caused more water to evaporate quickly.”

A follow-up experimentThe work of a scientist is never done. Answering one question inevitably opens the doors to many more. As for Vincent, he’ll likely be back in the kitchen repeating his experiment with regular butter instead of light butter. “Doing this again,” he wrote in his report, “would not be a problem at all since I love baking and eating cookies!”

Do you experiment in the kitchen?
Write to us at scienceandfooducla (at) gmail (dot) com and tell us about your best kitchen experiment. We’ll feature our favorite feats of kitchen science on the site!

 

Vincent’s Scientifically-Tested Chewy Chocolate Chip Cookies
Adapted from Mel’s Kitchen Café

Ingredients

1 cup light butter, frozen and cut into cubes
1 cup granulated sugar
1 cup packed light brown sugar
3 large eggs
1 teaspoon salt
1 teaspoon vanilla
1 1/2 teaspoons baking soda
3 1/2 cups flour
2 cups chocolate chips


Directions

Preheat oven to 350 degrees. Cream butter and both sugars together until well mixed. Add eggs and mix for 2-3 minutes, until the batter is light in color. Add salt, vanilla, baking soda and mix. Add flour and chocolate chips together and mix until combined.

Drop cookie batter by rounded tablespoon onto parchment paper or silpat lined baking sheets and bake for 10 minutes until lightly golden around edges but still soft in the center.

 


Liz Roth-JohnsonAbout the author: Liz Roth-Johnson earned her Ph.D. in Molecular Biology at UCLA. If she’s not in the lab, you can usually find her experimenting in the kitchen.

Read more by Liz Roth-Johnson


Brownie Hacks & Cookie Engineering

brownie-comparison-relish

Get ready for the holidays! Check out these helpful guides to engineering your perfect brownies and cookies. Read more

The Science of Cookies

How would you describe your perfect chocolate chip cookie? Thin and chewy? Ultra-crispy? Thick and cakey? Whatever your preference, knowing how to manipulate the ingredients in a basic cookie recipe is the first step toward chocolate chip cookie bliss. At last week’s “Science of Cookies” student event, graduate student Kendra Nyberg showed us how to achieve two very different cookie textures by riffing off of the classic Toll House chocolate chip cookie recipe.

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Cookies wait to be tasted (left) while Kendra explains how gluten makes cookies chewy (right)

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Thin, chewy cookies (left) and thick, soft cookies (right)

Thin, Chewy Cookies from Smitten Kitchen
These cookies are all about moisture. A wetter cookie dough spreads more during baking, creating a much thinner cookie. Extra moisture also promotes gluten development in the cookie dough, creating a slightly denser, chewier cookie. This recipe from Smitten Kitchen maximizes moisture content by using melted butter, less flour, less egg white (which can dry out cookies), and a higher brown-to-white sugar ratio (brown sugar can help retain moisture) than the classic Toll House Recipe.

ThinChewyCookieRecipe

Thick, Soft Cookies from My Baking Addiction
Where the previous cookies craved moisture, this recipe from My Baking Addiction removes extra moisture to create thicker, less chewy cookies. Increasing the flour content and using extra cold butter creates a drier dough that spreads less easily in the oven; adding baking powder to the dough lends extra fluffing power. The reduced moisture in this dough also limits gluten formation for a slightly softer (less chewy) cookie.

ThickSoftCookieRecipe

Of course, this is barely the tip of the cookie engineering iceberg. There are so many ways to tweak a cookie recipe to achieve different textures. In addition to this brief introduction, the internet is full of great resources for cookie hacking. This particularly handy guide from Handle the Heat clearly show some of the ingredient manipulations described above. If you end up experimenting with your favorite cookie recipes, be sure to tell us about it in the comments below!


Liz Roth-JohnsonAbout the author: Liz Roth-Johnson is a Ph.D. candidate in Molecular Biology at UCLA. If she’s not in the lab, you can usually find her experimenting in the kitchen.

Read more by Liz Roth-Johnson


WikiPearls & Dunking Science

msnose1toned

Harvard professor David Edwards creates a new edible food packaging, and Chef Heston Blumenthal investigates why dunking cookies in milk (or tea) makes them taste so delicious. Read more

Butter Basics & Carl Sagan’s Apple Pie

CarlSaganPie

The New York Times discusses the proper care and handling of butter in baked goods, and Carl Sagan’s epic baking advice gets turned into an awesome recipe. Tastes like science! Read more