This document summarizes a student's biology lab experiment investigating how different types of flour affect cookies. The student baked four batches of cookies, each using a different flour: all-purpose flour, cake flour, whole wheat flour, and gluten-free flour. Their results found that the all-purpose flour cookies were normal in appearance and soft inside, while the cake flour cookies were flat and crispy. The whole wheat flour cookies were thicker and denser. The gluten-free flour cookies did not hold together and were just crumbs. Research showed these differences were due to the protein and gluten content of the flours.

1. 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

2. 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

3. 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

4. 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.

5. 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.

6. Apartment Therapy, 2012. Web. 07 Nov. 2012.
<http://www.thekitchn.com/whats-the-difference-cake-flou-
74565>.
Page: 1
Experiment Guidelines
Working alone or with a partner you will conduct a simple
biological experiment outside of class and write a word-
processed scientific report on your topic. The empirical study is
worth a total of 100 points as described in the deadline section,
below.
· Pay special attention to the deadlines - missing deadlines will
hurt your grade even if the final report is excellent. As stated in
my instructors’ syllabus, I deduct 10% for every week that an
assignment is late.
· All experiment assignments are due via Turnitin on
Blackboard at the beginning of class. I WILL NOT be accepting
paper assignments. Anything turned in after the due date on
Blackboard will be considered late and points will be docked.
· Each student must write his or her own draft and final report,
even if you worked with a partner.
· Write your own report and do not share it! Do not turn in 1
report with 2 names; you will both get 0 points.
· Copying even parts of the text (not the results) will yield a 0
score for all persons involved and probably a loss of
participation points and campus discipline.
· If your words match those of any web site we find you will
receive 0 points and campus discipline.
Deciding on a topic.
· Think of something about biology that you think is cool.
Genetics. Plants. Bacteria. Animal behavior (If you have a hard
time, flip through your BIO 100L manual and take a look at
what we will cover this semester and see if something strikes

7. your fancy).
· Google it.
· Find out more about it and then ask yourself a question. “I
wonder what makes plants grow faster”, “I wonder what kind of
surfaces grow the most bacteria”, “I wonder if there are more
types of animals that live in a woody area or a desert area”.
· Once you have a question, start thinking about how you would
experiment to answer your question. Don’t bog down by telling
yourself: “It’s interesting but I have no idea how to do an
experiment on it.” I can help you with this. The goal is for you
to experience the process of questioning, constructing an
hypothesis, designing an experiment (hopefully simple!)
collecting data, analyzing it and then writing about the whole
process, and hopefully practice writing well.
·
Topic Limitations
1. ABSOLUTELY NO MANIPULATION EXPERIMENTS ON
VERTEBRATES. This includes projects such as:
a. Feeding fish different foods to study growth.
b. Giving your lactose intolerant cousin milk to see how he
reacts.
c. Giving humans ANYTHING to ingest.
d. Vertebrates include:
i. You, your dog, cat, friends, family, fish, birds, most house
pets.
e. I realize it may sound harmless to give your friend a can of
coke and then record their heart rate to see if the caffeine has an
effect, but this class does not have the proper insurances to
allow that. If you turn in a proposal or a topic on these types of
projects, I will dock points. If you turn in a draft or a final
report on these types of projects you will receive ZERO credit.
2. You are allowed to perform OBSERVATIONAL experiments
on vertebrates. This includes:
a. Going to a pet shelter and recording animal behavior

8. b. Completing a biodiversity study in two different areas
c. Survey studies on humans
3. Make sure your project has BIOLOGY in it. This is a biology
class!! When you come up with an idea think to yourself “what
about this is the study of living things”.
a. Recording the evaporation rates of different liquids is
PHYSICS, not biology.
b. Recording the pH of household liquids is CHEMISTRY not
biology.
c. How music affects people is PSYCOLOGY, no biology.
4. The research must be conducted independently and not from
previous courses or from the internet.
Based on your observations of the world around you, pose a
question about some biological phenomenon of interest.
1. Develop a hypothesis about a part of your question that can
be tested using the scientific method.
2. Design an experiment to test your hypothesis.
a) What equipment (plants, pots, watering can, etc.) and
supplies (fertilizer, etc) will you need?
b) What specific information, (“data”, numbers, height in mm,
or temp., in °C,) will you need to gather, and how will you
gather it? (Will you stick the thermometer in the soil or hold it
on the leaves?)
c) What will your controls be? (Plants NOT treated with your
experimental process…etc.)
d) What one factor will be varied in your experimental group?
3. Some supplies may be available from the laboratory. If you
can’t supply all the materials that you will need to conduct your
study- ask for them. Ask early so there’s time to find
alternatives!
4. Make sure your experiment can be conducted in the time
frame allowed. (Especially critical for people who want to grow
plants!!)
5. Use the correct format for writing your paper.
Due Date
Assignment

9. Points
Criteria
Tue 9/10
Thur 9/12
Topic
5
You and your partner’s names. A prospective title, and one or
two sentences describing what you wish to study. You can
change this topic later but only with my approval.
Tue 9/24
Thur 9/26
Proposal
15
One-page proposal that includes: Hypothesis, Identification of
dependent and independent variables, Materials list (indicate
those that must be provided by your instructor) Outline of the
steps in the proposed method including controls, if applicable,
and when, where, and how you plan to do the experiment
Reference the provided Rubric.
Tue 10/29
Thur 10/31
Draft
30
3-4 page preliminary draft of results obtained from initial
experiments. This should basically be a complete final draft
with the initial results of your experiment. The more work you
put into the draft, the less work you will have on the final
report.
Reference the provided Rubric.
Tue 11/21
Thur 11/23
Final Report
50
4-5 following the format utilized in scientific journals.
Reference the guidelines to writing scientifically.

10. Reference the provided Rubric.
6. With the exception of “Title”, Include the headings as part of
your report.
For help with scientific writing look at:
http://writing2.richmond.edu/training/project/biology/biology.ht
mlhttp://www.columbia.edu/cu/biology/ug/research/paper.html
The help from the Columbia University page includes some
particularly helpful examples of correct and incorrect examples
Experiment Report Guide
ADVANCE d4 Working alone or with a partner you will do a
simple biology experiment outside of class and write a scientific
paper on your topic. The experiment is worth a total of 100
points as described in the deadline section, below.
· Pay special attention to the deadlines - missing deadlines will
hurt your grade even if the final report is excellent.
· Assignments are due at the start of your class, although
individual instructors may move a date by a week or two.
· Each student must write his or her own draft and final report,
even if you worked with a partner.
· Copying even parts of the text (not the results) will yield a 0
score for all persons involved and probably a loss of
participation points and campus discipline.
· Write your own report and do not share it! Do not turn in 1
report with 2 names; you will both get 0 points.
· If your words match those of any web site we find you will

11. receive 0 points and campus discipline.
· Electronic copies must include your name as the “Author” on
the first page, along with the name of your non-author partner,
if you had one.
Deadlines:
Due Date
Assignment
Points
Criteria
2/10-2/13
Topic
5
You and your partner’s names. A prospective title, and
one or two sentences describing what you wish to study. You
can change this topic later but only with approval of your
instructor.
2/24-2/27
Proposal
15
One-page proposal that includes: Hypothesis,
Identification of dependent and independent variables,
Materials list (indicate those that must be provided by your
instructor)
Outline of the steps in the proposed method including controls,
if applicable, and when, where, and how you plan to do the
experiment
4/7-4/10
First Draft
30
Two to three page preliminary draft of results obtained from
initial experiments, in other words, What happened? Many

12. instructors chose to require a complete draft of the final text.
4/21-4/24
Final Draft
50
Four to five pages following the format utilized in scientific
journals, as further described below. Include in the report the
headings as listed.
Specifications:
1. The research must be conducted independently and not from
previous courses.
2. Assignments must be double-spaced with 1-inch margins.
3. Font size must be 11-12 points in Times, New Century
Schoolbook, Arial, or Palatino.
4. Points will be deducted for late work.
5. Each part successfully completed will be a part of the report's
final score.
For help with scientific writing check out this web site:
http://writing2.richmond.edu/training/project/biology/biology.ht
mlhttp://www.columbia.edu/cu/biology/ug/research/paper.htmlT
he help from the Columbia University page includes some
particularly helpful examples of correct and incorrect examples.
Approach your overall experiment ideas with these points in
mind:
1. Based on your observations of the world around you, pose a
question about something biological.
2. Develop a hypothesis about a part of your question that can
be tested using the scientific method.

13. 3. Design an experiment to test your hypothesis.
a) What equipment (plants, pots, watering can, etc.) and
supplies (fertilizer, etc) will you need?
b) What specific information, (“data”, numbers, height in mm,
or temp., in °C,) will you need to gather, and how will you
gather it? (Will you stick the thermometer in the soil or hold it
on the leaves?)
c) What will your controls be? (Plants NOT treated with your
experimental process…etc.)
d) What one factor will be varied in your experimental group?
4. Some supplies may be available from the laboratory. If you
can’t supply all the materials that you will need to conduct your
study- ask for them. Ask early so there’s time to find
alternatives!
5. Make sure your experiment can be conducted in the time
frame allowed. (Especially critical for people who want to grow
plants!!)
6. Use scientific format for writing your report.
7. With the exception of “Title”, Include the headings as part of
your report.
Format for Final Report:
Title
Introduction
ADVANCE d4Include your hypothesis and your reasoning
behind it. Discuss the thought processes that led to your

14. hypothesis. Why is this experiment of interest? What would you
hope to learn by doing this? Are there widespread
misconceptions that you will address? You will review the
existing literature in this section.
ADVANCE d4You must use a minimum of three resources
relating to your topic. At least one of these must be a printed
source such as you would expect to find in a library and at least
one must be an electronic reference from the Internet. In this
section, summarize and discuss what you have read, and how
this ties in to your topic. Back up any statements you make with
correctly-cited references, listed later in your bibliography. You
can use Wikipedia to get information to educate yourself but
you may not rely on this and you should not quote it or copy
from it. Any information you get from internet sources should
be confirmed from a second, high-quality source.
ADVANCE d4 Materialsand Methods
ADVANCE d4Write this section in paragraph form and tell
what you did for your experiment and what materials you used.
Tell what your controls were and state what were your
dependent and independent variables.
ADVANCE d4Results and Discussion
ADVANCE d4Here you present your results and say what they
mean in terms of your hypothesis. Present your data in tables or
graphs and discuss in paragraph form what the results indicated
and if your hypothesis was supported. If your results turned out
differently than you expected, what possible factors/causes
might account for that, and what possible alternate hypotheses
might be posed to explain these data?
ADVANCE d4Bibliography
ADVANCE d4List your references in one of the standard
bibliographic formats, such as CBE style manual.

15. About your topics
While you can find ideas on line we’ve seen most “science fair”
projects on the internet and don’t want to see them again. The
point is for you to have an idea of your own. Yes. We know
that’s hard. We sometimes let people do modified versions of
projects they find on-line but using on-line ideas leads to-on
line copying all too often. Find something that interests you
and sit with a pencil, paper, and your imagination for 20
minutes. You’ll be surprised how much is in your own head.
Cool stuff. Honestly.
For your initial idea, don’t bog down by telling yourself: “It’s
interesting but I have no idea how to do an experiment on it.”
Your instructor, or the course coordinator, can help you with
this. Most of the time we have to tell folks to do less, not more,
in their methods. We know you’re not going to cure cancer. The
goal is for you to experience the process of questioning,
constructing an hypothesis, designing an experiment (hopefully
simple!) collecting data, analyzing it and then writing about the
whole process, and hopefully practice writing well.
Some limits! For research on “animals” use mealworms,
crickets, or earthworms available from pet stores and bait shops.
You may not conduct a study that gives alcohol to a human.
You may not use alcoholic beverages in your study (for
example, on plants or snails) unless you are 21 or over. You
may not use dangerous processes in your study (eg.; smoking,
tanning without sunscreen, etc.) You will not be given bacteria
to take home. And…. No experimenting with chemicals on pet
vertebrates!No giving your dog a medicine, for example. You
should expect that you will have to provide all your own
chemicals, and supplies. However, we have a few supplies we
can lend- with sufficient advance notice. Make your supply
requests to your instructor.