Understanding Traditional Cold Process Soap Made With Natural Oils & Fats
Soap, in its truest and most traditional form, is a simple but powerful product created through a chemical reaction between natural oils or fats and an alkaline solution. This process has been used for centuries and remains one of the most respected methods of soap making today — known as cold process soap making.
At its core, traditional soap is not a detergent, a cleanser base, or a melt-and-pour product. It is a substance formed through chemistry, craft, and time.
The Science Behind Soap: Saponification
When soap is made using the cold process method, a reaction called saponification takes place.
Saponification occurs when:
- Oils or fats (such as olive oil, coconut oil, tallow, or shea butter)
- Are combined with an alkaline solution (usually sodium hydroxide dissolved in water)
During this reaction:
- The oils are transformed into soap
- A natural by-product called glycerin is created and retained within the bar
This naturally occurring glycerin is one of the reasons traditional cold process soap feels conditioning and gentle compared to many commercial cleansers, where glycerin is often removed.
What Makes Cold Process Soap “Traditional”?
Cold process soap making is considered traditional because it:
- Uses raw oils and fats
- Relies on natural chemical transformation, not pre-made bases
- Preserves glycerin
- Requires curing time for the soap to fully develop
Unlike modern mass-produced soaps, cold process soap is not rushed. After the soap is poured into moulds, it must be left to cure for several weeks, allowing excess water to evaporate and the bar to harden, mellow, and improve in performance.
The Role of Natural Oils and Fats
The oils and fats used in soap making are not interchangeable — each one contributes specific qualities to the final bar.
For example:
- Olive oil contributes mildness and conditioning
- Coconut oil provides cleansing power and lather
- Animal fats (such as tallow or lard) create hard, long-lasting bars with a creamy lather
- Butters add richness and skin feel
A soap recipe is essentially a carefully balanced formula, designed to create a bar that cleans effectively without stripping the skin.
What Cold Process Soap Is — and What It Isn’t
Traditional cold process soap:
- ✔ Is made through saponification
- ✔ Contains naturally occurring glycerin
- ✔ Is created from oils, fats, and an alkaline solution
- ✔ Requires curing time
It is not:
- A detergent
- A surfactant blend
- A melt-and-pour base
- A cosmetic cleanser with added soap flakes
Understanding this distinction is important, especially for those learning to formulate or sell handmade soap.
Why Cold Process Soap Feels Different on the Skin
Because cold process soap is made from whole oils and retains glycerin, it often feels:
- Less stripping
- More conditioning
- Balanced rather than harsh
The final feel of the soap depends heavily on formulation, curing time, and ingredient choice — which is why learning the fundamentals of soap making is so important.
A Craft Rooted in Knowledge and Patience
Traditional cold process soap making sits at the intersection of science and craft. It requires:
- Respect for chemistry
- Understanding of ingredients
- Patience during curing
- Intentional formulation
When done correctly, the result is a simple, functional product that has stood the test of time — soap in its most honest form.
What You’ll Learn Next at The Soap Makers Hub
Throughout this blog, we’ll explore:
- The cold process method step by step
- How to choose and balance oils
- Natural colourants and additives
- Essential oil blending for soap
- Common mistakes and how to avoid them
Whether you’re just starting out or refining your skills, understanding what soap truly is, is the foundation everything else is built on.
The Soap Makers Hub® 
Leave a comment