How to make transparent soap bars
Transparent and translucent soaps are popular even today. To cater to demand there are several types of transparent or translucent soap bars available in the market. The first see through soap bar was a rosin glycerin soap bar developed by Andrew Pears in 1789. The ingredients of Pears patented transparent soap were sodium palmitate, natural rosin, glycerine, water, C12 soap, rosemary extract, thyme extract, coupled with suitable fragrance. Even today the Pears soap is made almost in the same way as developed by Andrew pears. It involves dissolving the raw soap and other ingredients in alcohol, pouring into moulds followed by up to 3 months of evaporation and drying.
In 1955 Neutrogena introduced a different type of transparent soap based on the patented formula developed by of Belgian cosmetic chemist, Edmond Fromont. His novel formula was based on triethanolamine soap. In this type of formulation the neutralizing cation was triethanolamine instead of the usual sodium. The ingredients of the Neutrogena bar were triethanolamine stearate, C12 – 18 soaps, glycerine, water, and a range of minor ingredients including a little lanolin derivative and fragrance. Triethanolamine forms acid soaps so the pH of the Neutrogena bar at pH 8 – 9 is lower than a regular soap with sodium as the cation.
Transparent soap formula
Quantity In grams
Lauramide DEA (Incromide LDEA)
Cocamidopropyl betaine (Mackam CB)
70% active sodium laureth sulfate(Mackol 70NS)
50% Sodium Hydroxide
In sufficient quantity
Procedure for making transparent soap bar
In the given formula on the right, cetareth-27 is a non-ionic surfactant, made from a mixture of high molecular mass saturated fatty alcohols and is available through bulk chemical manufacturers and suppliers. The given formula is for making high foaming clear cleansing bar. Here sodium strearate is formed in situ by reaction between stearic acid and sodium Hydroxide. Sodium strearate imparts hardness to the bar, hence by modifying it’s quantity the hardness of the bar can be manipulated. The bar is non-tacky and releases from its mold easily when cooled.
- Step 1: Except Urea, Stearic Acid, and 50% Sodium Hydroxide, all other ingredients are blended together and heated with stirring to 65oC until a uniform mix is formed.
- Step 2: Urea is then added slowly to the uniform mix formed in step 1 while maintaining the temperature at 65oC. The mass is stirred at 65oC until it is clear.
- Step 3: Now Strearic acid is added to the content of step 2 with stirring and temperature is raised to 75oC. Stirring is continued till it becomes clear.
- Step 4: While maintaining the temperature at 75oC, 50% Sodium Hydroxide is poured in the contents of step 3, and is stirred for 2 to 3 minutes .
- Step 5: Suitable and stable fragrance is then added, and the preparation is stirred until it looks uniform and clear at 75oC.
- Step 6: Now the hot liquid is poured in the soap mold and allowed to cool to room temperature, the formed transparent soap bar is then packaged suitably for market.