How to Make Crude Soap at Home

Soap is the result of a simple chemical process.

Soap has been around for some 5,000 years, but it is only in the last two centuries that scientists have refined it into the many varieties we use today. Basically, soap is a combination of sodium or potassium salts with fatty acids. This mix gives it the ability to clean, because soap itself dissolves in water and also dissolves grease and oils, which are then carried away by the water. "Crude soap" is created by making animal or vegetable fats react with sodium hydroxide (caustic soda or lye), a potentially dangerous alkali. Sodium chloride (salt) is added as a purifying agent.

Things You'll Need

• Coconut oil
• Sodium hydroxide
• Sodium chloride
• Heat source -- gas ring or Bunsen burner
• Distilled water
• 2 plastic spoons
• Plastic container (for mold)
• 3 beakers
• Cheesecloth
• Absorbent paper

Instructions

Make the Soap

1. Place 1 fluid ounce of coconut oil and 1 1/2 fluid ounces of sodium hydroxide solution into a heat-proof beaker.

2. Heat to a gentle boil, stirring constantly and slowly.

3. Boil for 20 minutes or until the liquid has evaporated.

4. Remove from heat and allow to cool.

5. Add 1 1/2 fluid ounces of distilled water to the soap mixture and stir with a clean plastic spoon.

Refine the Soap

1. Heat 5 fluid ounces of sodium chloride solution in a heat-proof beaker until almost boiling.

2. Add to the mixture.

3. Break up any large lumps using a clean plastic spoon.

4. Cover the beaker of soap mixture with cheesecloth and pour the liquid into a beaker. The solids left behind are the soap.

5. Heat a further 5 fluid ounces of sodium chloride solution, add to the soap solids, and filter again through clean cheesecloth.

Use the Soap

1. Press the soap lumps between two pieces of absorbent paper to remove as much liquid as possible.

2. Buy or improvise a soap mold. This can be any plastic container about the size of a piece of soap.

3. Press the soap into the mold and dry overnight.

4. Test whether the soap will produce suds by washing your hands with it.

Tips & Warnings

• The traditional way to make lye is to mix ashes from a fireplace with water. Ashes are a rich source of sodium hydroxide.

• Adding salt not only gets rid of impurities but also makes soap milder and less harsh on skin.

• Sodium hydroxide burns on contact. Wear goggles, gloves, and a lab coat or apron when using it. If it gets on your skin, wash immediately with plenty of water.

• If it gets in your eyes, immediately flush with plenty of water for at least 15 minutes and get medical advice. Do not wear contact lenses when working with sodium hydroxide.

• Remove clothing splashed with sodium hydroxide immediately and wash before reuse.

References

• Super Soap Making: "Chemistry of Soap Making"
• The Chemistry of Clean: "Make Your Own Soap to Study Soap Synthesis;" January 2011

Resources

• Bioline International: Journal of Applied Sciences...Vol. 6, Num. 1, 2002
• Santa Monica College: Making Soap -- Saponification