Need an experiment report for my Bio 100 Lab class.

Biology100L

27 November 2012

A “Flour Batch” of Cookies

Introduction:

Our hypothesis for this experiment is that we believe that the type of flour used for baking will affect the end product and consistency of the cookie, including its physical appearance. We felt that the flour would affect the baking product because depending on the type of flour used, each contains different enzymes, which react differently when it is being baked. This experiment particular caught my attention because I personally love to bake. During the holidays one year I was baking wedding cookies, and I had accidently used all-purpose baking flour instead of the cake flour that the recipe called for. I did not realize that I had used the wrong type of flour until I bit into one of the cookies to sample it. It was then that I realized that the cookies were rather dry. I checked all my ingredients and realized the mistake I had made. Then I made another batch of cookies using the cake flour that the recipe had called for and when the cookies were done, they were nice and moist inside. So, from the experiment I would like to learn about the affects that different types of flour have on baking goods.

At the end of this experiment we decided to look up information on the different types of flours and why our cookies turned out the way they did. Since I wanted to learn more about the baking process of the cookies I looked at all the different flours and the reasoning to their reactions, which includes the ingredients that the flour is made of as well as how the flour is prepared. After reading several articles it was evident that the common factor all the flour had was that they are all made of wheat, but what makes them different is “how they are milled, the wheat they are made from” but most importantly how much protein they contain (“What’s the Difference”). Of the four different types of flour that we used, we were able to find that all-purpose flour contains 10-12% protein, while cake flour only has about 7-8% protein.

The amount of protein in the flour is referred to as the amount of gluten it contains. The gluten in the flour “ helps to give the structure and texture of the baked good” (“What’s the Difference”). If you are making a baked good that is nice, soft and “fluffy” then you would use a “soft flour” that has less gluten, versus if you are making a “chewy bread” then you would need a flour with more gluten (Narsai). After reading through several articles I was able to find that a possible reason why the cookies baked with gluten free flour did not look like the original batch is because it did not contain the protein needed to give it the texture and shape of the cookie that was baked with all-purpose flour. I was also able to connect the reason why the cookies baked with cake flour did not rise as they should have. Since cake flour only has about 7-8% protein, as mentioned before, the cookie did not rise or keep its round shape as did the batch of cookies made with all-purpose flour. At the end of my research I realized that it is possible to bake with any type of flour as long as adjustments are made, like adding corn starch to cake flour or pastry flour (“What’s the difference”). The reason why I found this information useful and important was because it not only related to our topic on baking cookies with different types of flour, but it also explained why there was a difference in the appearance and consistency of all four batches of our cookies.

Considering the gluten free diet, we chose to use gluten free flour for our experiment. After reading the article from Mayoclinic.com we realized that people with celiac disease should not have gluten in their diet. People will celiac disease must therefore eat something else that substitutes the gluten. We found that if a person with “celiac disease eats gluten, then their small intestines can get inflamed” (Staff, Mayo). Gluten can be found in substances like “wheat, barley, rye and cookies”, unless the recipe is altered (Staff, Mayo). When you use all-purpose flour to bake cookies, the gluten provides a type of mold that holds the cookie together, its structure, therefore, substituting gluten-free flour for all-purpose flour will not create the same results if another substance is not combined with the gluten-free flour.

To further my investigation on the effects of baking products I turned to a book, “Baking 9-1-1: Rescue from Recipe Disasters” by Sarah Phillips. This book contains not only recipes but also explanations as to what the ingredients do to the finished product of the baked good that one is making. Ingredients are one of the most important parts of baking, like Phillips mentions, “baking a recipe successfully is all about the balance among ingredients” (Phillips, 13). We can see that “in general, ingredients can be divided into two types, sometimes overlapping: “tougheners/strengtheners” (flour, whole eggs, egg whites, and milk) are essentially what hold the recipe together”, which is what we were testing in our experiment (Phillips, 13). The other type of ingredients, the “tenderizers/weakeners” (fat, sugar,egg yolks, and acid such as lemon juice or cream tartar), do the opposite:they actually soften the structure” (Phillips, 13). Through this statement we can see that adjusting the ingredients in our recipe, like we did with the different types of flour, would affect the end product of the cookie. After looking at the types of ingredients a break down of flour used is given, which includes wheat flour, which is one type of flour that we used for the experiment. “Wheat flour provides the structure in baked goods from both its gluten-forming proteins, glutenin and gliadin, and its starches” (Phillips, 17). Not only does it provide the structure to the baked goods, but it is also “the only grain that contains significant amounts of gluten-forming proteins” and that is the reason why it is the “only flour that can be truly leavened” (Phillips, 17). Gluten is important in baked goods because it gives the “dough elasticity, strength, structure, and gas-retaining properties” (Phillips, 17).

Materials and Methods:

For this experiment we made four batches of cookies, each with different types of flour. The materials that we used for this experiment are typical ingredients that you would use to bake a cookie, which includes: eggs, vegetable oil, water, vanilla extra, baking soda, butter, brown and white sugar, oatmeal, milk and white chocolate chips, walnuts, all-purpose flour, cake flour, whole wheat and gluten free. Along with the ingredients for baking we used measuring cups, mixing bowls and thin baking pans. The dependent variable in this experiment is the consistency and appearance of the cookie. The independent variable for this experiment is the types of flour that we used. The four different types of flour are all-purpose flour, cake flour, whole wheat and gluten free. For this experiment we followed the recipe for all four batches of cookies, but the only thing we changed was the type of flour that we used. This ensured that the experiment would be controlled and the only variable changing would be the flour. Before observing the cookies we allowed all four of the batches to cool for five minutes, then we proceeded to look at them from the outside and cut them in half and look at the consistency of the cookies.

Results and Discussion:

After baking all four batches of cookies we looked at the physical appearance and the consistency of the cookies. The cookies made of all-purpose flour had a normal cookie like appearance, meaning that they were rounded and in a mound shape due to the oatmeal and walnuts. When we cut the cookies in half, we were able to see that although the cookie was crisp on the outside, the inside of the cookie was gooey and soft. When we used the cake flour, however, the cookie was flat and thinner, for example, they had a larger diameter than the all-purpose flour cookies. Since the cookie was flat, it allowed for the cookie to bake and become crisper than the first batch of cookies. The cookies made with whole wheat flour appeared to be just like the cookies made of all-purpose flour, but once we cut the cookie in half we were able to see the difference. The whole-wheat flour cookies were thicker, denser and more compact. The gluten free batch of cookies did not really hold together. They ended up just being crumbs after the cookie finished baking because they were not mixed with proper ingredients to make the cookie bind together.

I believe that our hypothesis was correct because we did see a change in the consistency and appearances of the cookies vary from batch to batch. In our hypothesis we said that we believed that changing the types of flour in a cookie recipe would give us different results in appearance and consistency of the finished product.

Bibliography

Narsai David. Cake Flour vs. All-Purpose Flour CBS San Francisco. CBS Local, 2012. Web. 07 Nov. 2012. <http://sanfrancisco.cbslocal.com/2012/09/15/narsai-david-cake-flour-vs-all-purpose-flour/>.

Phillips, Sarah. Baking 9-1-1: Answers to Your Most Frequently Asked Baking Questions, Rescue from Recipe Disasters, 40 Recipes for Every Baker. New York: Simon & Schuster, 2003. Print.

Staff, Mayo Clinic. Gluten-free Diet: What's Allowed, What's Not. Mayo Clinic. Mayo Foundation for Medical Education and Research, 20 Dec. 2011. Web. 30 Oct. 2012. < http://www.mayoclinic.com/health/gluten-free-diet/my01140 >.

Staff, The Kitchn. What's the Difference? Cake Flour, Pastry Flour, All-Purpose Flour, and Bread Flour. The Kitchn. Apartment Therapy, 2012. Web. 07 Nov. 2012. <http://www.thekitchn.com/whats-the-difference-cake-flou-74565>.