5b. Raw Materials and Cold Process
Soap Manufacturing > 5. Small Scale Soap Making
RAW MATERIALS USED IN COLD PROCESS
The raw materials used in cold process are mainly natural vegetable oils and animal fats. Almost all kinds of natural oils can be used to produce soap with Cold Process system. Expert Soap Makers use oil blends composed with many types of oils, to produce a soap with specific characteristics like hardness, cleansing and lather. These features depends from the Fatty Acids carbon chains included in each oil.
Essential Oils are used as fragrances and natural colorants can be mixed in different ways to obtain handmade soaps with a very attractive looks.
COLD PROCESS SAPONIFICATION
Oils and caustic soda solution are heated up to 40°- 50°C. The oils before, and only in a second step the caustic soda solution, are poured inside a pot/drum where are mixed by means of electro-mechanical blades, or also by hand. After the saponification, perfume, additives and other ingredients are added in the liquid soap. When the batch is ready, the soap is poured inside plastic or wooden boxes, where it becomes solid after a couples of days or more, depending from the oils specifications and from the quantity of water used in the caustic soda solution. When the soap blocks are solid but fresh, they are cut manually or by means of a wire cutter, to produce finished soap bars. Before to be used, the soap bars have to mature for few weeks; after that the saponification process is really finished.
The Hot Process is an improvement of cold process. During the saponification, the pot/drum is heated to speed up the reaction. Anyway the Hot Process, due to the temperature, can damage some of the precious properties of the natural ingredients. To calculate the amount of Caustic Soda and other parameters, you can use our Soap Calculator for handmade soap.
EXAMPLE OF OIL BLEND USED IN COLD PROCESS
Blend of 75% RBD soybean oil with 25% coconut oil.
The soybean oil is liquid at 20°C while, at the same temperature the Coconut oil is still solid.
After the heating at 50°C both oils are liquid and the oil blend is ready for the saponification process.
COLD PROCESS SAPONIFICATION
Caustic soda solution is added to the oil blend. A small mixer is used to amalgamate the two reagents. The high speed of the mixer decrease the saponification time; after less than 30 minutes the soap is ready to be pour is a plastic mould.
After a couples of day the soap can be extracted from the mold and after some days it is ready to be used.