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close this bookHow to Make? An Improved Soap .. Not just for more Foam (GTZ, 1993, 71 p.)
close this folderC. Saponification of simple fats
View the documentC.I. Peanut oil
View the documentC.II. Copra oil
View the documentC.III. Cotton oil
View the documentC.IV. Shea butter
View the documentC.V. Palm oil
View the documentC.VI. Palmkernel oil
View the documentC.VII. Tallows (cow and mutton)
View the documentC.VIII. Fat (pork)
View the documentC.IX. Neem oil
View the documentC.X. Pourghere oil
View the documentC.XI. Castor oil
View the documentC.XII. Sesame oil

C.X. Pourghere oil

Extracted from physic nut (Jatropha curcas, L), a rustic tree, widespread in the inter-tropical regions, it is a non edible oil with marked purgative qualities.

Physical and chemical characteristics:

Density at 15 °C:


Solidification point:

-13 to +5 °C

Iodine number:

95 - 110

Saponification value:

185 - 210

INS Factor:

75 - 115

Concentration of appropriate alkaline solution for saponification:

15 to 45 °Be

The soda soap is white and soft. It quickly produces an abundant and stable foam, possesses a good cleaning power, and develops a smooth effect on the skin.

Preparation of soap

Pourghere oil presents neither a strong coloration nor a marked unpleasant odor, its pretreatment for soapmaking can be limited to simple purification (washing in salted boiling water).


Traditionally the saponification of pourghere oil is carried out with a potassium alkaline solution extracted from plant ashes.

For production of improved soap, the semi-hot process is well indicated.


100 Kg of purified pourghere oil;
13,90 Kg of caustic soda solution at 15 °Be;
36 Kg of caustic soda solution at 40 °Be;
5 Kg of finely sprayed kaolin.


How to conduct the operations:

- Weigh the quantity of purified oil and heat it in the boiler at 55 - 60 °C;
- Stop the heating and slowly add, in small portions, the low concentration alkaline solution by stirring;
- When an emulsion appears, add progressively (by stirring) the strong alkaline solution (the temperature of the mixture increases strongly and indicates a good achievement of the saponification);
- Let the temperature decrease down to 55 °C and mix in the kaolin (then eventually the color and the scent);
- Pour into moulds and let it get cold and hard;
- Take out of moulds and cut into bars and pieces.