Materials

Report
Science Academic Fair
Binder and Backboard
Requirements
Science Binder Contents
The following items must be in the binder and in this order:
•Title page
•Research paper
•Bibliography
•Abstract –this is done after the experiment
•Research Plan
•Purpose
•Hypothesis
•Materials
•Procedure
•Data
•Results
•Conclusion
•ISEF forms
•Journal
•Pictures
Once you type everything for the binder,
you’ll print each page twice.
• One copy for the binder
• The second is modified a little for the
backboard
For those selected to go to the Diocesan
Science Fair:
The title page can not have your name on it.
You will have to reprint the title page.
Therefore, please save all typed pages in a
file and backup to flash drive.
Your name can go on the back cover of your
binder.
Writing the Abstract
Follow handout provided earlier in the year.
Abstract
The purpose of this project was to investigate the effect of different amounts of
acid on the curdling process of milk. This was accomplished by experimentation and
comparative studies. For my experiment, I used four different types of milk: skim, 2%,
whole, and whipping cream. For each milk type, I heated the milk, poured the same
amount into five separate containers, added different amounts of lemon juice (acid) to
each sample, allowed the milk to cool, poured the milk through a cheesecloth to separate
the curds from the whey, allowed the samples to dry overnight, and weighed the curds left
on the cheesecloth. My hypothesis for this project was that the higher the acid content of
the milk, the quantity of curds produced would be higher. Higher milk fat contents
should also increase the amount of curds produced. The constants and controls in my
experiment were the amount of milk used and the temperature the milk was heated to.
The variables in my experiment were the amounts of acid added to the milk, and the
different types of milk used. The results of the experiment showed that when more lemon
juice was added to the milk, more curds were produced. The experiment also showed that
higher milk fat contents produced more curds. The results show that my hypothesis was
correct. If I were going to do this experiment again in the future or expand this
experiment, I would put more lemon juice in the milk and keep Increasing it to try to
determine the maximum amount of curds that could be produced.
Writing the research plan: Please follow the handout provided
Research Plan
•The problem: The purpose of this project is to investigate the effects of different amounts of acid on the
curdling process of various types of cow’s milk.
•Independent variable: different types of cow’s milk and different amounts of acid
•Dependent variable: the amount of cheese produced due to the curdling process of the milk with the acid
•Controls: the amount of milk used and the temperature the milk is heated to
•Quantitative measurement: weight (in grams)
•Experimental and control groups: The control group for each milk type is the cup with zero lemon juice
added. The experimental groups are the varied amounts of lemon juice added
•Materials: skim milk, 2% milk, whole milk, whipping cream, lemon juice, tap water, whisk, saucepan,
thermometer, cheese cloth, strainer, scale, measuring cup, 21 plastic drinking cups, 5 clothespins, hanger,
newspaper, and Sharpie pen. The different milks, cheese cloth, and lemon juice will come from the grocery
store. The kitchen items are from my kitchen. The scale is borrowed from my dad’s engineering company.
•Procedure: For each of the different milk types, the following steps were followed. Divide the cups into
sets of five and label 1, 2, 3, 4, and 5. Weigh the empty cups and record in journal. Add 31/3 cups of milk
into saucepan and heat on stove top to simmer (195° F) while stirring with a whisk to avoid milk from
burning. When 195° F is reached, remove saucepan from stove top and pour warm milk into each of the
cups to the mark. Weigh cups again and adjust as necessary so that the weight of milk in all cups is 150
grams. Subtract the weight of the empty cups from the weight of the cups with the milk to provide the
weight of the milk. Add 0, 15, 25, 40, and 55 drops of lemon juice to cups 1 through 5 and swirl. Allow the
milk to cool for about 1½ hours. Meanwhile, cut the cheesecloth into equal sizes, and weigh each piece.
After the milk has cooled, place a piece of cheesecloth (folded over once) into the strainer, and pour the
milk over the cheesecloth so that the whey passes through, but the curds do not. Fold the cheesecloth
containing the curds up from the corners, and hang the cheesecloth with a clothespin on a hanger to allow
the whey to continue to drain out onto newspaper overnight. Weigh the cheesecloth with the curds.
Subtract the weight of the cheesecloth to provide the weight of the curds obtained.
•
Hypothesis: For each of the different milk types, the more drops of acid that are added, the more
curds will be produced. Also, the higher the percent milk fat, the amount of curds produced will increase.
•
Research explanation: My hypothesis is explained from the research I conducted in which I learned
that the curdling process of milk happens as a result of the changes in the structure of the milk protein, or
casein, from the changes in the pH of the milk. Adding lemon juice changes the acidity of the milk and
therefore causes the milk to curdle. As the protein structure of milk changes due to acidification, the casein
begins to coagulate. However, the best form of milk to use is fresh, raw milk because it contains bacteria
that feed on the lactose, or the sugar in milk, to form lactic acid. Along with lactic acid, the acid added in
acid coagulation of milk will produce larger quantities of curds.
In the research, I also learned that cheese can be made from the milk of different mammals. These
milks contain varying amounts of fat. In “Cheese Primer,” Steven Jenkins states that, “Fat is important to
an individual cheese’s character, but less important overall, since cheese can be made from milk that is
full fat or reduced fat, or from skim milk that has virtually no fat at all.” In his book, Jenkins also explains
that, “On average, cow’s milk contains (by weight) about 87% water, 3½% protein, 3¾% fat, 5% lactose,
along with water-soluble vitamins,…., and minerals…” Because of the permeability of the casein structure
and the changes that occur to the structure of casein during acidification, the higher the fat content of the
milk used, the more fat may be trapped in the clumps that form in the coagulation of the milk, which
increases the percent of curds produced.
•
Bibliography:
Purpose
The purpose of this project is to investigate the effect of different
amounts of acid on the curdling process of milk. This will be accomplished
by experimentation and comparative studies. This research will include
information about the cheese making process, different types of milk used for
cheese making, and the effect of acids on milk.
Hypothesis
For each of the different milk types, the more drops of acid that are
added, the more curds will be produced. The higher the percent milk fat, the
amount of curds produced will increase.
Materials
 skim milk
 2% milk
 whole milk
 whipping cream
 lemon juice
 tap water
 whisk
 saucepan
 thermometer
 cheesecloth
 strainer
 scale
 measuring cup
 21 plastic drinking cups
 5 clothespins
 hanger
 newspaper
 Sharpie pen
Procedure
For each of the different milk types, the following steps were followed.
•Divide the cups into sets of five and label 1, 2, 3, 4, and 5.
•Weigh the empty cups and record in journal.
•Add 31/3 cups of milk into saucepan and heat on stove top to simmer (195° F) while stirring with
a whisk to avoid milk from burning.
•When 195° F is reached, remove saucepan from stove top and pour warm milk into each of the
cups to the mark.
•Weigh cups again and adjust as necessary so that the weight of milk in all cups is 150 grams.
•Subtract the weight of the empty cups from the weight of the cups with the milk to provide the
weight of the milk.
•Add 0, 15, 25, 40, and 55 drops of lemon juice to cups 1 through 5.
•Allow cups to cool for about 1½ hours.
•Meanwhile, cut the cheesecloth into equal sizes, and weigh each piece.
•After the milk has cooled, place a piece of cheesecloth (folded over once) into the strainer, and
pour the milk over the cheesecloth so that the whey passes through, but the curds do not.
•Fold the cheesecloth containing the curds up from the corners, and hang the cheesecloth with a
clothespin on the hanger to allow the whey to continue to drain out onto newspaper overnight.
•Weigh the cheesecloth with the curds.
•Subtract the weight of the cheesecloth to provide the weight of the curds obtained.
Conclusion
The results of my experiment are that the more lemon juice
drops are added, the more curds are produced. Also, the higher the
milk fat content of the milk there is, the more curds are produced.
Journal
•Spiral or composition notebooks
•Keep a hand written journal to record day-today
details of your project.
•Include description of what needs to be done to
complete experiment.
•Can be put in the back pocket of binder
Display Board
•Must be 91 cm tall, 121cm wide, and 30 cm deep
• All information is neatly typed and organized in
professional manner.
•Must include 2 self-generated items, such as graphs,
charts, models, pictures, or drawings.
•Must include:
•Title
•Purpose
•Hypothesis
•Materials
•Procedures
•Data
•Results
•Conclusion
•Abstract
Oral Presentations
•Be prepared to present your project to the judges.
•Five to seven minute presentation including title and
purpose, and summarizing procedures, data, results,
and conclusion.
•Expect questions and answer with confidence.
•Demonstrate clear communication skills.
•Maintain eye contact.
•Display enthusiasm.

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