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		Soap Production (CDI, 1995, 70 p.)
			(introduction...)
			1. INTRODUCTION
			2. GENERAL INFORMATION ON SOAP
			3. THE RAW MATERIALS
			4. THE MANUFACTURE OF SOAP
			5. THE TREATMENT OF OILS AND FATS
			6. SAPONIFICATION: COLD PROCESS
			7. SAPONIFICATION: SEMI-BOILED PROCESS
			8. SAPONIFICATION: FULL BOILED PROCESS
			9. SAPONIFICATION: CONTINUOUS PROCESS
			10. THE COOLING AND DRYING OF SOAP
			11. FINISHING SOAP
			12. PRODUCTION OPTIONS
			13. GENERAL CONSIDERATIONS FOR MANUFACTURING PROCESSES
			14. CDI EXPERIENCE IN SOAP FACTORY PROJECTS
			15. IMPLEMENTING A SOAP FACTORY PROJECT
			16. EQUIPMENT MANUFACTURERS
			17. TURNKEY SUPPLIERS AND ENGINEERING OFFICES
			18. THE SOAP MAKERS
			19. DEVELOPING A SOAP FACTORY PROJECT
			20. CHECKLIST: RAW MATERIALS
			21. CHECKLIST: THE SOAP MARKET
			22. CHECKLIST: DATA FOR A FEASIBILITY STUDY
			ANNEXES
			23. SERVICES OFFERED BY THE CDI
			OTHER TITLES
			BACK COVER

6. SAPONIFICATION: COLD PROCESS

Figure

The cold process is the most elementary batch process. In a saponification vessel it involves the gradual addition to fats of just the right quantity of soda lye (± 32% by weight) to ensure complete saponification. The mixture is kept under vigorous agitation for approximately 2 hours, and the dyes, perfumes and additives are generally added at this stage. The process does not include the removal of impurities or separation of the glycerine which is produced.

Crude soap is drawn off as soon as the bulk of the mixture thickens, and is poured as it is into cooling frames, where the saponification process continues for one or more days. Crude soap (fatty acid content: 58%) is then removed from the frame, cut into blocks, and sent to the finishing line. It is advisable to filter the fats to avoid the formation of impurities and to use 1/3 coconut or palm kernel oil to ease emulsification and facilitate saponification. The process requires considerable expertise in the saponification process.

The process is simple, inexpensive and not highly mechanised. It requires only modest investment in equipment. This is why it is particularly well-suited to the manufacture, in small quantities, of a low-grade soap aimed at an undemanding clientele with limited purchasing power, such as in a rural area.