Understanding the method of making natural artisanal soap
How do you transform simple vegetable oils into a soft, solid, and pleasant-to-use natural handmade soap? The answer lies in an ancient and fascinating chemical reaction: cold process saponification.
At Oréra, each soap is handcrafted in Quebec, in small batches. Formulation, mixing, molding, cutting, and curing require time, precision, and a good understanding of the role of each raw material.
In this guide, we clearly explain how cold process soap is made, what happens to the oils and lye during the reaction, and how the ingredients influence hardness, lather, and skin feel.
What is cold process saponification?
Saponification is the chemical reaction between fats — such as vegetable oils and butters — and a sodium hydroxide solution, also known as caustic soda or lye. This reaction transforms the initial ingredients into soap and glycerin.
It's called the "cold process" method because the soap mixture is not cooked for hours. Moderate heat can be used to melt some solid butters, but the reaction then continues naturally in the mold.
This method allows for the creation of a soap rich in glycerin, which is naturally produced during saponification. Glycerin contributes to the pleasant feel of the soap and is not removed from the formula.
To remember: oils do not remain entirely in their original form. A large part of their fatty acids is transformed into soap. Therefore, it is the balance of the entire formula — and not the reputation of a single oil — that determines hardness, lather, cleansing power, and the final feel.
The four main steps in making natural handmade soap
The manufacturing process seems simple on paper, but it requires precise calculations, controlled temperatures, and strict safety rules. Here is the journey of an Oréra soap, from formulation to its arrival in your bathroom.
Formulation
Each recipe is calculated according to the fatty acid profile of the chosen oils and butters. These proportions influence the hardness, lather, mildness, and longevity of the soap.
Preparation
The lye solution is precisely incorporated into the fats. The mixture gradually thickens to "trace," a sign that the emulsion is stable enough.
Molding and Cutting
Clays, botanicals, milks, or other planned additives in the formula are incorporated, then the mixture is poured into a mold. After hardening, the soap loaf is unmolded and hand-cut.
Curing Time
The bars typically rest for four to six weeks in a dry, ventilated area. This curing process allows water to evaporate and helps the soap become firmer, more durable, and more pleasant to use.
Since the soaps are hand-poured and hand-cut, their color, pattern, and weight may vary slightly from batch to batch. These nuances are part of the authentic character of handmade production.
Why is lye used in soap?
It is impossible to make true solid soap without an alkaline agent. For bar soap, this agent is typically sodium hydroxide. Lye is essential for the reaction, but it is not intended to remain free in the finished product.
When a formula is correctly calculated, manufactured, and left to cure, the lye reacts with the fats to form soap. The soap maker can also plan for a superfat, which is a deliberate proportion of fats greater than what is needed for the complete reaction.
Important: pure caustic soda is corrosive, and its handling requires training, protective equipment, and a suitable space. The finished soap is a different product from its initial ingredients.
What is the role of ingredients in cold process soap?
In a soap formula, ingredients work together. Some primarily contribute to structure and lather; others modify texture, color, or the sensation during washing. Here are the main families we use.
Oils and Butters
Olive oil promotes a soft, creamy lather. Coconut oil provides hardness and abundant lather. Shea butter enriches the formula, while castor oil helps stabilize the lather. Avocado, sweet almond, and rice bran oils allow for nuanced soap profiles.
Clays and Botanical Powders
Clays naturally provide color and a unique slip to the lather. Ghassoul, pink clay, white clay, and certain botanical powders also help create soft or lightly exfoliating textures.
Milks, Oats, and Honey
Depending on the recipe, goat or coconut milk can replace part of the liquid. Finely ground oats provide a silky texture, while honey influences the color, lather, and sensory character of the bar.
Essential oils and colors
We favor subtle colors derived from clays, plants, and botanical extracts. When essential oils are used, they are used sparingly and in concentrations adapted to the product. Therefore, not all soaps are scented, and this simplicity is particularly suitable for people seeking a no-frills routine.
Soap is a rinse-off product: its main role is to cleanse. It does not replace a moisturizer or dermatological treatment. If your skin is very reactive or if you live with a skin condition, seek advice from a healthcare professional.
Some Oréra natural handmade soaps to discover
Each formula has its own balance of fats, clays, milks, and botanical additives. Here is a selection of handmade soaps for different scent and texture preferences.
How to choose a natural handmade soap?
Start by determining the sensation you're looking for and the intended frequency of use. The ingredient list, presence of fragrance, and exfoliation level are often more helpful than a long list of promises.
- For a very simple formula: choose an unscented soap or one with few additives.
- For a creamy lather: look for soaps formulated with milk, oats, or a rich balance of gentle oils.
- For occasional exfoliation: prefer a bar containing poppy, coffee, or another exfoliating particle, without excessive scrubbing.
- For the face: remember that the pH of real soap is alkaline. Some skin types tolerate it well, while others prefer a cleanser specially formulated for the face.
To extend the life of your soap, let it dry between uses on a well-drained soap dish. A bar that constantly sits in water will soften and dissolve much faster.
Frequently Asked Questions about Natural Soap Making
Is lye still present in the finished soap?
In a correctly formulated soap where saponification is complete, the lye has reacted with the fats to form soap. Calculations, manufacturing controls, and curing are essential to obtain a compliant and safe bar.
Why do I have to wait several weeks before using the soap?
Curing primarily allows some of the water to evaporate. This makes the soap harder, more durable, and generally more pleasant to use. For artisanal soap makers, a period of four to six weeks is common, depending on the formula.
Is glycerin added to the soap?
Glycerin naturally forms during saponification. In cold process handmade soap, it usually remains in the bar instead of being separated from the product.
Why can two soaps of the same model be slightly different?
Each batch is mixed, poured, and cut by hand. Patterns, color nuances, and shape may therefore vary slightly without altering the intended use of the product.
Can natural soap treat eczema or acne?
No. A cosmetic soap is primarily for cleansing and should not be presented as a treatment. For a skin condition, consult a doctor, pharmacist, or dermatologist.
Kristel Audet
Founder and creator of natural skincare
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