How to Make Liquid Soap with Caustic Soda Safely and Effectively

Making liquid soap from caustic soda involves a process known as saponification, where fats or oils react with a strong alkali to produce soap. This guide offers a step-by-step process to help you make liquid soap safely. Follow these instructions, and you'll be able to create your own homemade, fragrant, and moisturizing liquid soap.

Materials Needed

Ingredients:

500g of oils: examples include olive oil, coconut oil, and palm oil 100g of caustic soda (sodium hydroxide) 300g of distilled water (Optional: 300g of fragrance oils, essential oils, and colorants)

Equipment:

Safety goggles and gloves A heat-resistant container for mixing A scale for accurate measurements A stick blender A large pot for cooking A thermometer A soap mold or container pH strips to test the soap

Safety Precautions

Working safely is crucial when making liquid soap with caustic soda. Follow these precautions:

Wear protective gear: Always wear gloves and goggles when handling caustic soda as it is highly corrosive. Work in a well-ventilated area: The fumes produced when mixing lye with water can be hazardous. Keep vinegar nearby: It can neutralize any spills of caustic soda.

Instructions

Prepare the Lye Solution

Measure 300g of distilled water and pour it into a heat-resistant container. Slowly add 100g of caustic soda to the water. Always add lye to water, not the other way around. Stir gently until fully dissolved. The mixture will heat up and release fumes. Let it cool in a safe area.

Prepare the Oils

Measure 500g of your chosen oils and combine them in a large pot. Heat the oils gently until they reach about 40-50°C (104-122°F).

Combine Lye and Oils

Once both the lye solution and oils are at a similar temperature (around 40-50°C), slowly pour the lye solution into the oils while stirring continuously.

Blend to Trace

Use a stick blender to mix the oils and lye until the mixture reaches a trace.

Cook the Soap

Cover the pot and cook the mixture on low heat for 1-2 hours, stirring occasionally. The soap will undergo a process called gel phase where it becomes translucent and thick.

Dilute the Soap

Add distilled water (about 1-2 liters) gradually while stirring. Continue to heat gently until the soap is fully dissolved in the water.

Add Optional Ingredients

Add fragrance oils, essential oils, or colorants if desired. Stir well to incorporate.

Test pH

Allow the soap to cool, then test the pH using pH strips. A safe pH for liquid soap ranges from 7 to 10. If it's too high, dilute it further.

Bottle and Store

Pour the soap into bottles. Label them and store them in a cool, dark place.

Notes

Curing: Liquid soap does not require a curing period like bar soap, but letting it sit for a few days can improve its texture.

Adjusting Consistency: If your soap is too thick, dilute it further with distilled water. If it's too thin, cook it longer to evaporate some water.

Conclusion

Making liquid soap with caustic soda requires careful handling and precise measurements, but it can be a rewarding process. Always prioritize safety and enjoy your homemade liquid soap!