ADM Biorenewables Education Laboratory Soap Lab
Summer Academy 06/10/2014
Gabriel Domingues & Matt Schul
Soap Lab
Learning Objectives:
• Gained an understanding of the saponification process.
• Gained an understanding of raw soap and its uses.
• Developed and processed different oil based soaps.
• Gained “hands-on” experience in the preparation, processing and fabrication of different oil
based soaps.
Learning Outcomes:
• Define saponification.
• Be able to discuss the process of saponification.
• Be able to define what a base and acid are.
• Be able to explain what triglycerides are.
• Be able to use pH strips to test soap after curing process.
Pre-Lab
Background
Saponification is a process in which a fat molecule is broken down by sodium hydroxide (lye)
into four smaller molecules; three of the new molecules are soap and one is glycerol. In simple
terms saponification is the name for a chemical reaction between an acid and a base to form a salt.
An acid is a molecule or ion that donates protons or hydrogen ions (H+) and/or accepts electrons,
and a base is any substance that donates electrons or hydroxide ions (OH-) and/or that accepts
protons.
When you make soap, you mix an oil or fat (which is your acid) with Sodium Hydroxide or Lye
(which is your base) to form soap (which is a salt). There are many different types of acids that
will react with your base and saponify. Your acid could be olive oil, coconut oil or vegetable oil just
to name a few. Each acid has a unique combination of triglycerides (compounds made of three
fatty acids attached to a single glycerol molecule) which combines with the base (sodium
hydroxide or lye) differently.
Figure 1. General saponification reaction
