Technical Information
What is Soap?
Soap colloquially; It is a substance used to clean greasy, dirty things. Soap in terms of chemistry; It is the sodium or potassium salt of fatty acids formed as a result of the reaction of all kinds of oils alone or in certain proportions of their mixtures with alkalis.
This chemical reaction is called saponification reaction and occurs with the mixing and blending of the ingredients which also creates heat (we say it is exothermic).The hydroxide part of the sodium hydroxide (caustic soda) is corrosive. But with the saponification reaction, the carbon from the triglyceride collects hydroxide and we obtain glycerin, a humectant which attracts and retain moisture on your skin.
Soap production Methods?
Selection of the oily substance mixture; It is made according to local economic conditions and the desired feature of the product. Selected oil or oil mixtures; They make a difference on the soap's properties such as removing dirt, foaming, wetting the surface and giving softness.
Production Techniques:
There are three different soap making methods used today. These are the methods;
1) Hot Soap Production Method (Marseille Method)
2) Cold Soap Production Method (Castile Method)
3) Continuous Production Method (Industrial Method)
Seven Steps To Make A Soap with Traditional Cold Soap Production Method
Getting started
First, be sure to work on a clear surface with clean instruments. Handle sodium hydroxide (a corrosive product) and soap paste carefully in a ventilated area to prevent burns. It is essential to wear gloves, safety glasses, a mask, and long clothing during each step of soapmaking. Above all, make sure to have time on your hands.
Step 1 | Preparing the oily and aqueous
These two phases are prepared separately, and each ingredient is weighed carefully. The aqueous phase consists of cold water and sodium hydroxide (lye, NaOH). Lye is necessary as part of the “cold process” soapmaking method because it transforms the fatty substance into soap paste through a chemical reaction. On contact with sodium hydroxide granules, the temperature of the water rises considerably and rapidly. With a large spoon, stir until completely dissolved. As for the oily phase, it is the soap base. This oily phase is also heated. When the respective temperatures of the two phases have been reached, the lye solution is poured into the oily phase (never the other way round). The mixture is stirred with a hand blender until the soap paste begins to take shape.
Step 2 | Making the soap paste
On contact with the lye, the chemical reaction begins, and the oil is transformed into soap paste. This process is called cold saponification. As it is mixed, the paste becomes homogeneous and thickens until grooves form on the surface (like fudge!). This is known as the “trace” stage. Be careful with splatters! The active ingredients and colours can now be added to the paste.
Step 3 | Adding the active ingredients
It is at this stage that essential oils, herbs, exfoliants, colours, and other active ingredients are added to the soap paste. The possibilities are endless! Caution: You must work fairly quickly because, depending on the ingredients, the chemical reaction can quickly.
Step 4 | Pouring the soap
The soap paste is now ready to be poured into a mould. This is where you can let your creativity run wild for the look of your soap bars! Once again, you need to be alert and proceed fairly quickly because the soap paste continues to thicken. You must therefore plan your design before starting to work on the recipe.
Step 5 | Rest period
Once you have poured the soap paste, you need to cover it with resin, and the mould with a towel or wooden board. This will help retain the heat produced by the saponification (an exothermic reaction) process. Let it rest like this for at least 12 to 24 hours. It is during this period that the soap hardens. The soap rises in temperature, and its appearance (colour, texture) may seem quite different. Don’t worry, everything will be fine when the soap is removed from the
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Step 6 | Unmoulding and cutting
A day later, the soap is ready to be unmoulded. Its consistency is comparable to that of a block of butter: it is strong enough to be handled, but soft enough to be easily cut. At Quai des Bulles, we cut our soap bars with handcrafted instruments, custom-made for our needs. We check all of our soap bars one by one to make sure they are perfect. At this stage of the process, the soap must be handled with care. It is then sent to dry.
Step 7 | Drying
A drying period is essential before the soap can be used. The soap bars are stacked on a wooden shelf and undergo an ambient air drying process that lasts at least 30 days. This period of time allows for the saponification process to fully complete and for the pH to adjust, making for a milder, less “caustic” soap. It is important to know that the drier soap bars become, the harder they become, and the longer their shelf life will be. Afterwards, the secret is to keep the soap bars in a dry and cool place, and to rotate them as needed. The use of a soap dish is essential to ensure proper drainage of your soap bar. Note that even after the 30-day drying cure, the appearance, smell, and colour of the soap may still continue to change (this does not affect its properties).