How do I make soap?
Astrid Hasund Thorseth avatar
Written by Astrid Hasund Thorseth
Updated over a week ago

Before you make soap, read about how soap works. We describe here how to make soap in a low resource setting using a cold process. These instructions are adapted from CAWST and PaceProject and explain how to make 4 kg of soap using palm oil as an example. We have chosen palm oil as it is widely available and makes a hard and long-lasting bar of soap that generates a lot of lather. It is possible to make soap on your own, but we recommend using at least two people to make the process easier.

Equipment

  • Thick rubber gloves

  • Safety glasses

  • 3 large glass or plastic bowls or plastic buckets (these must be solid or heavy duty)

  • Measuring cups

  • 3 large silicone spatulas/large plastic spoons/large wooden spoons

  • Weighing scale

  • Water-tight moulds (made from plastic, wood, cardboard or waxed paper). You can also use silicone moulds

  • Knife or wire to cut the soap

  • Cloth, waxed paper (e.g. baking paper) or plastic bags to line the mould (if not a silicone mould) so that the soap can be removed from the mould easily.

10 rules for safe soap making

  1. Always wear thick rubber gloves.

  2. Always wear safety glasses to protect your eyes when you are handling lye.

  3. Always wear long-sleeved clothing, long pants/trousers and covered shoes (no sandals).

  4. Avoid inhaling fumes when you mix the lye in the liquid by working in a well-ventilated room and covering your mouth and nose with a mask or scarf.

  5. Use wood, glass or plastic utensils and pots to prepare soap. Do not use metal as this can react with the lye and cause an explosion.

  6. After using utensils for soap preparations they should never be subsequently used for handling food.

  7. Use a disposable tablecloth or newspaper to cover your table or bench when preparing soap - throw these away once you have finished.

  8. Make sure you have running water available near your workstation. In case of direct contact with lye, rinse immediately and contact your doctor.

  9. When cleaning up after you have finished making the soap, continue to wear rubber gloves and safety glasses at all times as raw soap is caustic and dangerous. Dispose of the tablecloth safely.

  10. Keep lye and raw soap out of reach of children and pets at all times.

Ingredients

1. Lye

Measurement: 370 grams/ 13.05 oz

There are two types of lye that you can use: 1) sodium hydroxide (NaOH), also known as caustic soda, or 2) potassium hydroxide, also known as potash. Sodium hydroxide is the most commonly used. Lye is a highly caustic product. If you choose to use potassium hydroxide, please note the measurements will be different. You can use a soap calculator to get the exact measurements. Lye can be purchased from most pharmacies.

2. Water

Measurement: 1.2 litres/ 1095 grams/ 38.65 oz

Use distilled water if available. Other options of “soft” water (not containing chlorine) include bottled water and filtered water. You can also use rain or spring water.

3. Fats

Measurement: 3 litres/ 2740 grams /96.62 oz of palm oil

You can use any of the fats or oils listed below. If you choose to use other types of oils rather than palm oil, please note that the measurements will be different. You can use a soap calculator to get the exact measurements.

Liquid oils

Palm oil, olive oil, corn oil, sunflower seed oil, fish oil, groundnut oil, soya bean oil, cottonseed oil, coffee bean oil, moringa oil

Semi-solid fats

Palm oil, castor oil, aloe butter, beeswax, animal fat or shea butter

Lauric oils

Coconut oil or palm kernel oil

Step 1: Prepare your work station

  • Set up your soap-making workspace in a well-ventilated room or outside.

  • Prepare your work station by removing any unnecessary objects and covering the work surface with a disposable cloth or old newspapers.

  • Prepare the mould. If you have a wooden or hard plastic mould you should cover this with baking paper or a plastic bag.

  • Lay out all of the equipment you need so it is at hand when needed.

  • Before starting, familiarise yourself with all steps of the recipe and ensure that you have all ingredients and equipment at hand.

Step 2: Measure your ingredients

  • Make sure you are wearing full PPE as listed in the ‘10 rules for safe soap making’ section above.

  • Ensure there are no children or animals in the room so that you will not be disturbed.

  • Firstly, measure the water using a measuring jug and pour into one of your mixing bowls. If you do not have access to a measuring jug you can use a clean 1L plastic bottle (you need 1 and ⅕ bottle fulls)

  • Measure 3 litres of oil and pour it into a second, large bowl.

  • Measure the lye using a weighing scale and add to your last empty bowl. Note: accurate measurements are important for a successful result.

Step 3: Mix the lye and water

  • Pour the lye slowly into the water while stirring. Note: never do this the opposite way (i.e. add the water to the lye) as this may cause an explosion.

  • Stir continuously until the lye is completely dissolved in the water. This solution will heat up so, once the lye is completely dissolved, leave it cool.

Step 4: Mixing the lye/water mixture and oil

  • Make sure the lye/water mixture and the oil is approximately the same temperature by touching the outside of the bowls.

  • Add the lye/water mixture to the oil while stirring.

  • Continue to stir continuously and carefully until it thickens, this process takes up to 30 minutes.

  • You can tell when you have stirred the soap enough by drizzling a spoonful of mixture over the surface layer - if it leaves a pattern similar to that in the photograph below you have stirred enough.

Picture: Source

Step 5: Put the soap into the mould(s)

  • Pour the soap into the mould (or moulds if you are using multiple smaller moulds) directly from the bowl. Alternatively you can use a ladle.

  • Cover the mould with plastic foil and then wrap with a towel or cloth tucked under the mould to protect it from dust. Leave the mould somewhere it won’t be disturbed.

Step 6: Setting the soap

  • Leave the soap to set for 24-48 hours.

  • Remove the soap from the mould and use a sharp knife or wire to cut the soap into bars.

  • Place the soap bars standing up and leave to cure (this is the process in which the soap hardens) for 4-6 weeks.

Step 7: Using your soap

  • After 4-6 weeks of curing, your soap is ready to use!

Common problems when making homemade soap

  • If your soap is dry or crumbling, it is possible that you have used too much lye.

  • Soap needs to stay in the mould for at least 24 hours. If the soap is still soft, leave it in the mould for up to 10 days. If the soap is still soft after 10 days it is unlikely to harden.

  • The oil or fat you used was dirty or rancid disturbing the curing/setting process of the soap and giving an undesirable result.

CAWST offers print-friendly materials for making soap and for teaching others how to make soap in English, French and Spanish. Another recipe for making soap in a low-resource setting is offered by the Pace Project (English only).


Want to learn more about making soap and alcohol-based hand rub at the community level:

Editor's notes:

Author: Astrid Hasund Thorseth

Reviewers: Ron Orcajada, Amy Pickering, Melinda Foran

Last update: 27.5.2020

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