INTRODUCTION
A CTIVITY 1
76
Stem
190.2
On a Shoestring
Ice Cream Science
Yes, the potential for messes seems highly likely, but you’ll be
surprised at the good, “clean” fun you’ll have when you make
ice cream.
The lesson possibilities for this one are nearly endless. Explore the history of ice cream, the chemistry of ice, salt and
exothermic reactions, or use it as an exercise in the scientific
method: what if you make the following recipe without salt?
QUICK GUIDE:
Prep Time: 20-30 minutes
Activity Time: 2 to 3 hours
Est. Cost: $20 to $25 depending on group size
Age range: 4 years – adult
OKLAHOMA AFTERSCHOOL NETWORK
76
A CTIVITY 1
Stem
190.2
On a Shoestring
190.2
Os
smium
13
26.96
Ice Cream Science
Al
Aluminum
31
69.72
Ga
Gallium
27
25
58.93
54.94
Co
Mn
Cobalt
Manganese
40
91.22
Zr
Zirconium
13
26.9
Al
Aluminum
You will be surprised at the
fun you will have making
ice cream in a baggie or a
coffee can.
Explore the history of ice
cream, the chemistry of ice,
salt and exothermic
reactions.
Ice cream in a baggie
Things You Need
1/2 cup milk
1/2 teaspoon vanilla
1 tablespoon sugar
4 cups crushed ice
4 tablespoons salt
2 quart size plastic storage
bags
1 gallon size plastic freezer
bag
a hand towel or gloves to
keep fingers from freezing
as well!
Mix the milk, vanilla and sugar together in one of the quart size bags.
Seal tightly, allowing as little air to remain in the bag as possible. Too
much air left inside may force the bag open during shaking.
Directions
Place this bag inside the other quart size bag, again leaving as little air inside as possible
and sealing well. By double-bagging, the risk of salt and ice leaking into the ice cream is
minimized. Put the two bags inside the gallon size bag and fill the bag with ice, then sprinkle salt on top. Again let all the air escape and seal the bag.
Wrap the bag in the towel or put your gloves on, and shake and massage the bag, making
sure the ice surrounds the cream mixture. Five to eight minutes is adequate time for the
mixture to freeze into ice cream.
Tips
Freezer bags work best because they are thicker and less likely to develop small holes, allowing the bags to leak. You can get away with using regular plastic storage bags for the smaller
quart sizes, because you are double-bagging. Especially if you plan to do this indoors, we
strongly recommend using gallon size freezer bags.
2
Coffee can ice cream
An alternative to the baggie method is to use coffee cans. The
recipe is the same, and may be doubled or tripled as the coffee
can can hold more liquid than the baggies. Put the mixture in
a standard size coffee can and seal with the plastic lid, then
place inside a larger “economy size” can.
Pack the large can with ice and salt, and seal with the lid. Students can roll the can back and forth on the ground (outside –
the condensation will drip) until the ice cream is set.
The time required to set the mixture will vary depending on
the number of servings in the can.
Sodium Chloride:
The chemical
composition of salt
281
11
Na
Sodium
287
17
CI
Chloride
What does the salt do?
Just like we use salt on icy roads in the winter, salt mixed with
ice in this case also causes the ice to melt. When salt comes
into contact with ice, the freezing point of the ice is lowered.
Water will normally freeze at 32 degrees F.
A 10% salt solution freezes at 20 degrees F, and a 20% solution freezes at 2 degrees F. By lowering the temperature at
which ice is frozen, we are able to create an environment in
which the milk mixture can freeze at a temperature below 32
degrees F into ice cream.
Click here to learn more about the chemistry of salt.
Who invented ice
cream?
Some say that the Roman Emperor, Nero, discovered ice cream.
Nero reigned over the Roman Empire from 54 to 68 AD.
Legend has it that runners brought
snow from the mountains to make
the first ice cream.
Roman Emperor Nero
But ice cream may actually have origins in ancient China as
early as 200BC using a recipe of frozen milk and rice.
In 1846, Nancy Johnson introduced the hand-cranked ice
cream churn in the United States and ice cream surged in
popularity. Then, in 1904, ice cream cones were invented at
the St. Louis World’s Fair.
Click here to learn more about the history of ice cream.
3
The Scientific Method
The Scientific Method is a way to ask questions and
achieve answers by making observations, performing tests and doing experiments.
H
Making ice cream without salt will NOT work,
because the melting ice around the ice cream
will never reach a cold enough point that will allow the fat content in the ice cream to freeze.
Hypothesis
Q
Question
By adding salt to the ice around the ice
cream, will the freezing/melting point of
the water be lowered to get the ice cream
cold enough to freeze, before all of the
ice melts?
T
Make many gallons of ice cream, some using
the “salt method”, and some with just plain ice
around the containers. See what works best
based upon your hypothesis.
Test
R
Research
The chemical components, or “ingredients” to salt, are sodium and chloride.
The chemical formula is NaCl. This is the
most common type of salt.
A
Analyze
Compare different methods of preparation such
as in the baggie, in an electric freezer, using a
hand crank freezer, or in a coffee can. You can
also analyze the difference in the salt vs no salt
method.
4
Key Terms
Click on the terms below to learn more about their meanings
Chemistry -a branch of physical science, is the study of the composition, structure, properties and change of matter.
Melting Point -the melting point (or, rarely, liquefaction point) of a solid is the temperature at which it changes state from
solid to liquid at atmospheric pressure.
Ice Cream -a frozen dessert usually made from dairy products, such as milk and cream and often combined with fruits or
other ingredients and flavors.
Chemical Compound-a pure chemical substance consisting of two or more different chemical elements.
Chemical Reactions -a process that leads to the transformation of one set of chemical substances to another.
Exothermic Reaction -a chemical reaction that releases energy in the form of light or heat.
States of Matter -one of the distinct forms that different phases of matter take on.
Condensation -the change of the physical state of matter from gas phase into liquid phase, and is the reverse of vaporization.
Definitions above are sourced from Wikipedia.
Other science terminology resources to explore:
The Science Dictionary
American Heritage Science Dictionary
5
Books about Careers
Police Officer Books:
Ready, Dee. Police Officers Help, Capstone Press Publishing,
1997 Grades Kindergarten – 5th
Adamson, Heather. A Day in the Life of a Police Officer,
Mankato, MN.: Capstone Publishing, 2004 Grades 1st – 3rd
White, Nancy. Police Officers to the Rescue, New York, NY:
Bearport Publishing, 2012 Grades 1st – 6th
Firefighter Books:
Goldish, Meish. Smoke Jumpers, New York, NY.: Bearport
Publishing, 2014 Grades Pre K – 3rd
Goldish, Meish. Firefighters to the Rescue, New York, NY.:
Bearport Publishing, 2014 Grades 1st- 6th
Goldish, Meish. City Firefighters, New York, NY.: Bearport
Publishing, 2014 Grades 2nd – 7th
White, Nancy. Aviation Firefighters, New York, NY.: Bearport
Publishing, 2014 Grades 2nd – 7th
Engineering Books:
Parmalee, Thomas. Genetic Engineering, Edina, MN.: ABDO
Publishing, 2008 Grades 6th – 8th
Farrell, Courtney. Green Jobs, North Mankato, MN.: ABDO
Publishing, 2011 Grades 9th – 12th
Hamen, Susan E. Engineering, Edina, MN.: ABDO Publishing,
2011 Grades 9th – 12th
Scientist:
Hanson, Anders. Scientist’s Tools, Minneapolis, MN.: ABDO
Publishing, 2011 Grades 3rd – 5th
McMullin, Ruth. EXPEDITIONS Scientist in the Field (Science Adventures from Nature and Science Magazine), Natural
History Press, 1969 Grades 6th – 8th
Chef Books:
Butterworth, Christine; Gaggiotti, Lucia. How Did That Get in
My Lunchbox?: The Story of Food, Somerville, MA.: Candlewick Pub., 2011 Grades 3rd – 5th
Laurentiis, Giada De. Naples! (Recipe for Adventure #1), Grosset & Dunlap Publishing, 2013 Grades 5th – 8th
Pilot/ Aviation Books:
Simons, Lisa M.B. The Kids’ Guide to Military Vehicles,
Mankato, MN.: Capstone Press Publishing, 2010 Grades Kindergarten – 1st
Anderson, Jameson; Whigham, Rod; Barnett, Charles. Amelia
Earhart: Legendary Aviator, Mankato, MN. Capstone Press
Publishing, 2010 Grades 3rd – 4th
6
Hamilton, John & Sue. UAVs: Unmanned Aerial Vehicles, Minneapolis, MN.: ABDO Publishing, 2012 Grades 6th – 8th
Veterinarian Books:
Salzmann, Mary Elizabeth. Veterinarian’s Tools, Minneapolis,
MN.: ABDO Publishing, Grades 3rd – 5th
Architecture Books:
Stern, Steven L. Building Greenscapes, New York, NY.: Bearport Publishing, 2010 Grades 3rd – 6th
Sandler, Michael Freaky Strange Buildings, New York, NY.:
Bearport Publishing, 2012 Grades 3rd – 6th
Riddle, John. Veterinarian, Broomall, PA.: Mason Crest Publishing, 2003 Grades 3rd – 8th
Stevenson, Neil. Architecture, New York, NY.: DK Publishing,
1997 Grades 6th – 8th
Thomas, William Veterinarian, Pleasantville, NY.: Gareth Stevens Publishing, 2009 Grades 6th – 8th
City Planning Books:
Leardi, Jeanette. Making Green Cities, New York, NY.: Bearport Publishing, 2010 Grades 3rd – 6th
Dentist Books:
Stockham, Jessica. Dentist, Childs Plan Intl. Publishing, 2011
Grades Pre K – 3rd
Macaulay, David. City: A Story of Roman Planning and Construction, Houghton Mifflin Harcourt, 1983 Grades 6th – 8th
Salzmann, Mary Elizabeth. Dentist’s Tools, Minneapolis, MN.:
ABDO Publishing, 2011 Grades 3rd – 5th
Chapnick, Samantha. Around New York City with Kids, New
York, NY. Fodor’s Travel Publishing, 2011 Grades 3rd – 6th
Energy Books:
Wheeler, Jill C. Eye on Energy Series, Edina, MN.: ABDO Publishing, 2008 Grades 3rd – 6th
Computers and Gaming Books:
Petrie, Kristin. Computers, Edina, MN.: ABDO Publishing,
2009 Grades 3rd – 5th
Orme, Helen, Energy for the Future, New York, NY.: Bearport
Publishing, 2009 Grades 3rd – 5th
Ray, Michael. Gaming: From Atari to Xbox, New York, NY.:
Britannica Publishing, 2012 Grades 6th – 12th
Society of Petroleum Engineers. Oil and Natural Gas, DK Publishing, Inc., 2007 Grades 6th – 8th
Wilkinson, Colin. Gaming: Playing Safe and Playing Smart,
New York, NY.: Rosen Central Publishing, Grades 6th – 12th
Marcovitz, Hal. Energy Security, Edina, MN.: ABDO Publishing, 2011 Grades 6th– 8th
7
S TANDARDS ALIGNMENT
The following alignments link
the Ice Cream Science activity to
the Next Generation Science
Standards.
For more information, click each
section.
Disciplinary Core Ideas: Structure and Properties of Matter
Grades K-2:
2-PS1-1 Plan and Conduct an Investigation to describe and classify
different kinds of materials by their observable properties.
2-PS1-3 Make observations to construct evidence based account of how
an object made of small set of pieces can be disassembled and made
into a new object.
2-PS1-4 Construct an argument with evidence that some changes
caused by heating and cooling can be reversed and some cannot.
Disciplinary Core Ideas: Structure and Properties of Matter
Grades 3-5:
5-PS1-1 Develop a model to describe that matter is made of particles
too small to be seen.
5-PS1-2 Measure and graph quantities to provide evidence that
regardless of the type of change that occurs when heating, cooling, or
mixing substances, the total weight of matter is conserved.
5-PS1-3 Make observations and measurements to identify materials
based on their properties.
Disciplinary Core Ideas: Engineering Design
Grades 3-5:
3-5-ETS1-1 Define a simple design problem reflecting a need or a
want that includes specified criteria for success and constraints on
materials, time, or cost.
3-5-ETS1-2 Generate and compare multiple possible solutions to a
problem based on how well each is likely to meet the criteria and
constraints of the problem.
3-5- ETS1-3 Plan and carry out fair tests in which variables are
controlled and failure points are considered to identify aspects of a
model or prototype that can be improved.
Disciplinary Core Ideas: Structure and Properties of Matter
Middle School:
MS-PS1-3 Gather and make sense of information to describe that
synthetic materials come from natural resources and impact society.
MS-PS1-4 Develop a model that predicts and describes changes in
particle motion, temperature, and state of a pure substance when
thermal energy is added or removed.
Disciplinary Core Ideas: Chemical Reaction
Middle School:
MS-PS1-2 Analyze and interpret data on the properties of
substances before and after the substances interact to determine if a
chemical reaction has occurred.
MS-PS1-5 Develop and use a model to describe how the total number
of atoms does not change in a chemical reaction and thus mass is
conserved.
8
Career Connect
Career Connect Video: Candice Blevins
This activity is a great start to understanding and exploring
the world of chemistry.
A lot of careers involve chemistry. They include many jobs
in the energy field, agriculture and medicine. Energy is one
of Oklahoma’s top industries and those who work in this
field need to understand chemistry to keep people safe.
Candice Blevins
Marathon Oil
STEM, women in science
Candice Blevins is a Health Environment and Safety Technician at Marathon Oil in Oklahoma City, Oklahoma.
Click on the video at right to hear her story.
Thank you!
STEM on a Shoestring was developed through the
generous support of the Kirkpatrick Foundation.
It is a project of the Oklahoma Afterschool Network.
2801 N. Lincoln Blvd., Suite 224
Oklahoma City, OK 73105
www.okafterschool.org
www.OKSTEM.com
405.601.9560