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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.VII. Tallows (cow and mutton)

They are similar fats, deposited by these animals as food stock in special parts of the body (mainly in the abdominal cavity). They can be extracted by cooking in presence of an acid or a base.

Physical and chemical characteristics:


COW

MUTTON

Density at 15 °C:

0,936 - 0,952

0,936 - 0,960

Solidification point:

30 to 38 °C

32 - 45 °C

Iodine number:

32 -47

31 - 47

Saponification value:

193 - 200

192 - 198

INS Factor:

146 - 168

145 - 167

Intake in insaponifiable:

0,3 - 0,8%

0,1 - 0,6%

Intake of alkaline solution indicated for saponification:

8 to 15 °Be

8 - 15°Be

Sodium soaps of tallow are grey-white to yellow-cream. Very hard (breakable) and less soluble in water, they produce a little, but stable foam. They possess a good washing power and a very smooth effect on the skin. Mutton tallow produces a soap having a specific odor.

Soap preparation
Pre-treatment

Due to the specific odor they produce, tallows should undergo a deodorisation before their saponification.

The extended washing in salted boiling water (with addition of essential plants extracts) can give good results.

Saponification

Saponification of tallow can be better made with light concentration alkaline solutions (8 to 15 °Be). It is however appropriate to use two solutions of different concentration semi-hot processing is also very well indicated.

Recipe:

100 Kg of purified beef suet;
66,6 Kg of caustic potassium solution at 8 °Be;
36,59 Kg of caustic soda solution at 35 °Be;
5 Kg of kaolin.


Figure

How to conduct the operations:

- Weigh the necessary quantity of purified tallow and heat it in the boiler up to a temperature of 55-60 °C ;
- Stop the heating and add slowly and by small portions the caustic potassium solution by stirring;
- Then add the portion of caustic soda solution by stirring on (the reaction produces a lot of heat);
- Let the temperature decrease progressively (add and mix in the secondary products when the temperature decreases down to 50 - 55 °C )
- Pour the soap into moulds;
- Leave it become cold and hard;
- Take out of moulds and cut into bars and pieces.