Sunday, 6 December 2015

Making Soap in the Village

Making Soap in the Village

Many years back we worked on making soaps in the village. The AIVIA (the precursur to KVIC) had the most detailed procedure descriptions, and the amount of effort that had gone in in Kumarappa's time to establishing village industries was evident. With those notes, and guidance from friends in the soapmaking industry, we finally found this process most effective.

 Warm (Modified Cold) process.
Bath Soap
 Neem oil                – 100ml
Coconut oil             – 100 ml
Caustic Soda          – 30g
Water                     – 120g
Talc (optional)        – 44g
Scent (optional)      – 3ml

Washing soap
Neem oil          - 400ml (Or Neem oil 360ml and Coconut oil 40ml, which gives a firmer soap)
Caustic Soda  -  55g
Water              -  190g
Talc                 -  250g

  • Oil + Caustic Soda + moisture = Soap (sodium salt of fatty acid) + Glycerine (10%)

·    Every oil needs a definite percentage by weight of caustic soda.  Coconut oil needs 18% to 19% caustic soda, neem oil needs 13.5%.     Also for every process, the caustic soda needs a definite concentration. For the warm process it is 2.8 to 3.8.
  • All oils are not suitable for soaps. Groundnut oil gives a soft soap and pongamia oil gives only a liquid soap. Using only coconut oil increases the cost and also makes the soap drying. Neem oil has the disadvantage of a strong small, needing more of perfume to mask it and so hiking the cost.

·   Fillers are only to increase weight, and can be bypassed. We tried using gram flour as a filler but not very successfully.
·    The commercial processes use full boiled/ settled process. With much higher temperatures and big machinery they produce soaps with better finish. They are also able to use cheaper oils, buy at wholesale rates, resell glycerine etc. which adds to their cost advantage. Still we are able to produce a good soap with a higher TFM (total fatty material) of 60%, compared to most commercial soaps
·    The soaps lose about 10% weight over a month of standing.

Process (Warm/ Modified cold process)
1.     Neem oil is purified by boiling with a small amount of salt solution and removing the sludge and skimming away the top foam. We skip this step as our neem oil is pure, being from seed and not fruit. Also, the strong small did not become noticeably less
2.     Caustic soda is dissolved in the water and the lye is left to cool for 5-6 hours. If colour dye is added, it is added here. We do not add colour.
3.     Oils are heated to 50C (the temperature where the finger can be dipped in the oil for less than a second.)
4.     Talc is mixed in the oil.
5.     Caustic lye is slowly poured in the oil while constantly stirring in the same direction. Stirring is done till the mixture thickens to a point ehrn thr stirrer leaves a mark in it. This takes about half hour. Coconut oil saponifies more easily. So when coconut oil and neem oil are both used, neem oil can be saponified first with more than half the caustic soda, and then the coconut oil and the remaining lye are added. We however mixed the oils together first and then mixed with the lye. If the oils are overheated, the reaction proceeds with much bubbling and overflowing. In such a case the soap sometimes becomes granular on stirring. It is supposed to become curdy again, but that did not happen. We maintained a 50C.
6.     Scent is added at the end as it is volatile and can evaporate.
7.     Checks for completion of the reaction
·        When the soap is lifted with a spoon and allowed to fall, it should fall in a thin transparent film. If it  looks turbid, either oil or alkali is in excess.
·        The soap rolled between fingers must form clean transparent strings.
            (There are other tests, but those tests have not worked satisfactorily for us.)
8.     The mixture is ladled into moulds lined with salt water. The salt water allows the soap to be removed easily later. The mixture in the mould needs to be pressed with a damp cloth to press out the air bubbles and give it a smooth surface. The moulds are kept covered and insulated and the reaction proceeds further for another week or two. The heat of saponificartion needs to be conserved by covering the moulds well.
9.     The soap should not be used for another 2-3 weeks as the reaction will be ongoing then.

1.     Caustic soda is hygroscopic and absorbs water. So both caustic soda and its solution should never be left open to air.
2.     Caustic soda should be added to water, and never the other way.
3.     Caustic soda burns and should never be touched by hand,
4.     Aluminium vessels should never be used as they fume and corrode. Plastic, steel and enamel vessels are fine.
5.     During saponification, stirring is to be done in one direction only.
6.     In the measures oil is usually given by weight. If we measure by volume, the conversions needs to be done.

·        The cost can never match that the low cost soaps like Lifebouy because in large scale commercial manufacture, the base used in niger soap, a by product in Sunlight soap, both made by the same corporate.
·        The soap wears out a little faster than many commercial soaps. It had a life similar to the khadi soaps.


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