Soap Casting for the Elementary/Middle School Classroom by Gerrie Wiersberg, Amy Burns,
James McCrobie, Keisha Solomon, Pat Benner
Time: One 45 minute class period.
NGSS
3-5-ETS1-1: People’s needs and wants change over time, as do their demands for new and
improved technologies.
MD State Standards
Grade 3, Science Standard 4 – Chemistry
Topic C. States of Matter
Indicator
1. Provide evidence from investigations to describe the effect that changes in temperature have
on the properties of materials.
Objectives
Based on data gathered from investigations, identify and describe the changes that occur to the
observable properties of materials when different degrees of heat is applied to them, such as
melting chocolate pieces, boiling an egg.
Observe and describe the changes cooling causes to the observable properties of materials when
they are cooled, such as freezing water in a straw, milk in an ice cream maker.
Grade 3, Social Studies Standard 4 – Economics
Topic A. Scarcity and Economic Decision-Making
Indicator
2. Examine the production process
Objective
c. Describe steps in the production process to produce a product
Grade 6, Standard 2 – Peoples of the Nation and World
Topic
Elements of Culture
INDICATOR
1. Describe characteristics that historians use to organize people into cultures
Objective
b. Describe and compare elements of culture such as art, music, religion, government, social
structure, education, values, beliefs and customs, from civilizations in early world history
Grade 6, Standard 5 – History
Topic
EMERGENCE, EXPANSION AND CHANGES IN NATIONS AND EMPIRES
INDICATOR
1. Analyze how civilizations emerged in the river valley areas
Objective
b. Compare major cultural, political and economic achievements of river valley civilizations,
such as the Tigris and Euphrates River Valley, the Huang River Valley, the Indus River Valley
and the Nile River Valley including Egypt, Nubia and Kush
Learning Objectives
1. Students will describe the physical properties of the starting materials and their final soap
product
2. Students will make real-world connects between soap making and the different types of
soap they use on a daily basis
Introduction
Ask the students to turn and talk with a partner about the number of times they use soap in a day
and the different reasons they use it. Call on a few students; then ask them if they would use
soap as often or for the same reasons if they had to make the soap by hand. Ask them to justify
their answers as to why or why not. Then read to them the brief history of soap making listed
below.
History of Soap making (build background knowledge)
Legend has it that soap comes from Mt. Sapo (where the word “soap” comes from) in Rome.
Animals were sacrificed on the top of this mountain. When it rained, water ran through the
ashes and fat, washing it down to the Tiber River. The women found clumps of a pale, waxy
substance floating in the water. The women washed their clothes by pounding them with rocks.
When the waxy substance was beaten with the clothes, it made lather, and the clothes got
cleaner. (Excerpted from The Everything Soapmaking Book by Alicia Grosso)
In colonial America, coals were placed in special boxes which were lined with rocks,
filled with ashes and covered with hay. Rainwater was then poured over the ashes, which
washed out lye (a thick brown substance). The lye was collected and poured into melted animal
fat and stirred and heated for several hours over a fire. This is how soap was made for home
use. The leftover ash (with the lye removed from it) was then added to vegetable crops and is
good for soil. Today companies make several different types of soaps with different properties
that are used for bathing, laundry, and cleaning.
Materials (provided in kit)
Soap Kettle
Soap cutting tool
Some molds
Pot holder mitts
Plastic measuring cups
2 plastic ladles – 1 black & 1 white
Spray bottle with rubbing alcohol
The Everything Soap Making Book
Materials (not provided in kit)
Glycerin soap base – In a 2 pound package, each square is approximately equivalent to 1 ounce
Stir sticks – craft sticks or plastic spoons would work
Molds (other than provided)
Spray cooking oil (for lubricating the mold, unless using a Teflon or silicone non-stick mold)
Soap fragrances and dyes
Soap “petals” or other inserts for soap
Trays for materials
Preparation Steps:
1) Build student background by reading the excerpted history of soap making found above.
2) Explain to students that while they won’t be creating soap the way that people in the past
did, they will be creating their own bars of soap, while examining the physical properties
of soap. (Students should have already had an introduction to properties of matter. If not,
conduct a mini lesson at this point).
3) Remind students of the steps to the Scientific Method.
4) Have students write predictions on their papers.
5) Have students smell each available scent. Students may only pick 1 scent. (soap dye is
determined by the color. Example: rose scent = red dye)
6) Divide students into six equal groups, depending on the scent they picked. Have students
sign the Project Team Contract (at bottom)
Steps for Experiment
Step 1. Plug in soap kettle. Have students examine and record the properties of the glycerin
before it is put into the kettle. Put a minimum of 16 squares of glycerin soap base into the soap
kettle. **This kettle must have a minimum of 1 pound to melt at a time ** (You will need at
least two 2 pound packages of glycerin for each class). Push button on kettle in a downward
motion, so that the “melt” sign lights up. Stir soap frequently with small, white ladle until
glycerin is melted (approximately 4-5 minutes. Melting point is 175 degrees F or 80 degrees C).
Allow students to observe and record what is happening to the glycerin as it melts. Glycerin is
observable through the clear lid of the kettle. Switch button on kettle to reflect “warm” cycle.
Cover with lid and let sit for 15 minutes.
Step 2. While students are waiting for glycerin to rest, have students measure out fragrance and
dye into measuring cup. Remember 1 cup of glycerin needs 40 drops of fragrance and 20 drops
of color. (In order to maximize number of uses, the number of color drops was limited.
Therefore, the soap will not be as dark as the dye indicates.) Students should take turns
measuring. All group members should help keep track of the number of drops. This would also
be a good time to view additional resources such as video clips, etc.
NOTE: Hobby Lobby sells dyes in containers which are easier to use than those from
Michael’s. However, they only come in blue, red, and yellow base colors. If you wish to make a
different color, use the guide below and use equal amounts of each base color.
orange- yellow and red
purple- red and blue
green- yellow and blue
turquoise- blue and yellow
pink- small amount of red
Step 3. Using large black ladle, spoon melted glycerin into measuring cup. Stir quickly & pour
into waiting mold. CAUTION: Bottom of cup will be hot!! Students must hold it by handle
only. THIS CAN ALSO BE A TEACHER PERFORMED ACTIVITY.
Step 4. Once glycerin is in mold, let sit. Soap may sit on counter to cool. If there is trouble
removing the soap from the mold, place in the refrigerator for 10-15 minutes. (Do NOT freeze
the soap, as it will cause it to sweat)
Step 5. Have students complete their student observation log. Have students discuss if they
think that it will take a longer or shorter period of time for the soap to cool, depending on the
size of the mold and why.
TIPS:
1) To add inserts (small toys, “petals”, etc.), pour a thin layer in the mold and allow it to
cool enough to form a skin (about 5 minutes). Push the insert gently through the skin so it
will stay anchored. Then fill the rest of the mold with melted glycerin.
2) For multicolor layers, follow the same directions as above. The first layer will be one
color, followed by a second/different color when cooled. Repeat as desired.
3) For a tie dye effect, use melted white glycerin (goat’s milk). Pour into mold then add
random drops of dye and swirl with a toothpick or thin craft stick.
4) To prevent bubbles from forming, spritz rubbing alcohol onto top of soap before it cools.
Soapmaking resources:
What makes soap foam?
http://health.howstuffworks.com/skin-care/cleansing/products/soap-foam.htm
Soap making Factory
http://www.youtube.com/watch?feature=player_embedded&v=_WnRdFiCEac
Children’s Books
Poetry
Video: The Culture and History of Soapmaking
http://www.youtube.com/watch?feature=player_embedded&v=jcaEQsynDdY#at=110
Soap Commercials
http://www.youtube.com/watch?v=or-O-43BkZ8
Lesson plan on buoyancy
http://sciencenetlinks.com/lessons/does-soap-float/
Global Soap Project (for service learning or national honor society hours)
www.globalsoap.org
Student Soap Making Observation Log #____ NAME: ________________________ DATE: ___________
1) What does your soap look like? List 3 properties:
a) ____________________________________________
b) ____________________________________________
c) ____________________________________________
2) What did you use for a mold? Why did you pick this mold?
_______________________________________________________________________
3) What are the different kinds of soaps that you have used? List two.
a) ___________________________ b) _________________________________
4) What are some items you can add to your soap to change its properties?
________________________________________________________________________
5) Why would you want soaps with different properties?
________________________________________________________________________
Student Soap Making Observation Log #____ NAME: ________________________ DATE: ___________
1. What does your soap look like? List 3 properties:
d) ____________________________________________
e) ____________________________________________
f) ____________________________________________
2. What did you use for a mold? Why did you pick this mold?
_______________________________________________________________________
3. What are the different kinds of soaps that you have used? List two.
a) ___________________________ b) _________________________________
4. What are some items you can add to your soap to change its properties?
________________________________________________________________________
5. Why would you want soaps with different properties?
________________________________________________________________________
PROJECT TEAM CONTRACT
Project Name:
Team Members:
Our Agreement
We all promise to listen to each other’s ideas with respect.
We all promise to do our work as best as we can.
We all promise to do our work on time.
We all promise to ask for help if we need it.
We all promise to________________________________
If someone on our team breaks one or more of our rules, the team may have a meeting and ask
the person to follow our agreement. If the person still breaks the rules, we will ask our teacher
to help find a solution.
Date:___________________________
Team Member Signatures:
________________________________________________________
_______________________________________________________
________________________________________________________
_______________________________________________________
________________________________________________________
_______________________________________________________
Have the teams assign the following roles:
• time keeper-keeps track of time.
• recorder-write down behaviors used to design and build the
structure (e.g. what questions did the team ask, how much of each
material was used, did the team test structure to see if it would
work, did the team redesign the model…).
• speaker- share the team’s experience with the whole group.
• leader/facilitator- keep the team focus and on task.