The two necessary ingredients to make soap are lye (a base) and oils or fats. Oils and fats are easy to find. You can use animal fat or plant oils – whatever is easy to get. Lye is not easy to buy. Lye must be made.
WARNING: Lye is caustic and corrosive. This means is will burn your skin. You MUST wear protective gloves and glasses when working with lye.
WHAT IS LYE?
Lye is a strong base. Industrial lye is the chemical sodium hydroxide or NaOH. This is used to make hard bars of soap. Lye that can be made at home is the chemical potassium hydroxide or KOH. KOH is used to make soft and liquid soap. This book tells you how to make KOH.
WHAT YOU NEED
To make lye you will need some equipment.
- Two plastic or stainless steel buckets. (DO NOT use aluminium – lye will burn aluminium)
- Clean river stones (optional)
- Clean straw (optional)
- Bricks or wood blocks to stand your bucket on.
You will also need these ingredients:
- Potash – get potash by burning one of the following plants and collecting its ash from:
- Plantain or banana skin
- Plantain or banana trees
- Olive trees or another hardwood
- Rain water (if possible) – the best soap is made from pure water. You could also use distilled water.
- Make a small hole in the bottom of one of your buckets. The hole should be the size of a nail. Plug the hole so nothing can get out the bottom of the bucket.
- Place the bucket with the plugged hole on bricks or wooden blocks. Place the other bucket underneath the plugged hole. If you are using river stones and straw place these in the top bucket. The river stones go in first. The straw sits on top of the river stones.
- Fill the top bucket 2/3 full with your ash.
- Add hot rain water or distilled water (if possible) on top of your ash. The potash should be wet but not floating.
- Leave the potash and water in the top bucket for around one day. KEEP IT COVERED.
- Remove the plug in the hole of the top bucket. The lye water should slowly trickle out into your bottom bucket. BE CAREFUL – THIS LYE COULD BE CAUSTIC AND CORROSIVE. WEAR GLOVES.
- Test the strength of your lye.
Don’t worry if you have some small pieces of ash in your lye. It should be a colour between light brown and black. If you want to remove any ash from your lye then filter it.
TEST THE STRENGTH OF YOUR LYE
- Take a chicken feather. Place it on top of your collected lye. If it dissolves (disappears) then your lye is strong enough.
- Take an egg. Place it in your collected lye.
- If it sinks your lye is too weak.
- If it floats just below the surface of your liquid your lye is just right.
- If it floats high in the liquid your lye is too strong
- If your lye is too weak then repeat the method above with your collected lye instead of water.
- If your lye is too strong add a small amount of vinegar until the egg floats just below the surface of the liquid.
Once you have made your lye you are ready to make soap. To make soft soap use the lye you have collected using this method.
To make hard soap add some common cooking salt to your lye collected using this method. Cooking salt is the chemical NaCl. The Na+ ions will replace the K+ ions in your lye and allow you to make hard soap.