How to Make Bath Soap


Materials/Ingredients (for 14 bars, 135 g/bar)

  • Refined coconut oil – 4.5 kg
  • Caustic soda solution (32 deg. Be) – 3.25 kg
  • EDTA (Ethylene diaminetetracetate) – 70 g
  • Citric acid – 70 g
  • Sodium chloride – 4.5 g
  • CDEA (Coco diethanolamide) – 50 g
  • Light mineral oil – 70 g
  • Scent to suit
  • Color (optional)


  • Pails – 16 L cap. (2 pcs); 20 L cap. (1 pc)
  • Basin (large)
  • Hydrometer – 0 – 70oBaume
  • Weighing scales – 10 kg cap.; 500 g cap.
  • Mold and cutter
  • Wooden stirrer/manual or electric mixer
  • Spatula, stainless

Preparation of Materials

1. Caustic soda solution, 32oBe: Dissolve 0.855 kg of caustic soda (NaOH) in 2.4 kg water. Cool to room temperature. Check the concentration with the hydrometer. Adjust if necessary and filter if needed before using.

2. Additives: Dissolve EDTA, citric acid and salt in 100 mL water. For color, make a 1% solution. Add color in oil.

Preparation of the Soap

  1. Weigh carefully the required quantity of coco oil. To make a colored soap, add about 10 mL of the 1% color in oil solution or the amount to suit the desired intensity of color.
  2. Add the required amount of caustic soda with stirring until the condensed milk-like consistency is attained. This usually takes 45 minutes to 1 hour.
  3. Add the dissolved additives and continue stirring for 5 minutes more.
  4. Add the light mineral oil, CDEA and scent. Stir for another 5 minutes.
  5. Pour the soap mixture into the moulder. Let it stand at room temperature for 12 hours or until soap solidifies.
  6. Remove soap from the moulder and cut into desired size.
  7. Stamp and pack. Allow to age for about 7 days to complete the saponification.

BATH SOAP (Tranparent)


  • Coconut oil – 100 gms
  • Stearic acid – 100 gms
  • Castor oil – 80 gms
  • Caustic soda solution (38oBe) – 160 gms
  • Glycerol – 85 gms
  • Alcohol – 100 gms
  • Sugar – 80 gms
  • Water – 80 gms
  • CDEA – 25 gms
  • Perfume (Optional)

Preparation of 38oBe Caustic Soda

Dissolve 1 kg caustic soda in 2 liters of waters. Cool to room temperature. Measure the concentration with a hydrometer. Adjust (if necessary) and filter if needed before using.


  1. Weigh all the ingredients
  2. Melt separately the stearic acid and coconut oil at 80-C.
  3. Add castor oil first before adding lye into the charge oil
  4. Mix caustic soda with alcohol; add slowly to fat charge with stirring. Temperature should not exceed 75-C.
  5. In a separate container, dissolve sugar in water at 80-C (remove any froth)
  6. Add to the soap mass, the glycerol, the water-sugar solution, and the CDEA stirring constantly.
  7. Cover and allow to stand until temperature reaches 60-C, add perfume and color (if needed).
  8. Transfer to mould or frame.

NOTE: Rapid cooling is essential for soap transparency.

For inquiries about the materials and ingredients used, please call DOST at Tel. Nos.: (632) 837-2071 to 82 locs. 2182, 2218, 2180



  1. By Saman


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