1. What is Sodium Hydroxide?
Sodium hydroxide (NaOH), also known as lye or caustic soda, is an alkaline compound used in many industries, including soap making. Its main role in saponification is to transform oils and fats into soap and glycerin, resulting in a solid cleansing product.
Important fact: Although sodium hydroxide is a strong compound, none of it remains in the final soap once saponification is properly completed.
2. How Is Sodium Hydroxide Used in Soap Formulation?
The process of making soap with sodium hydroxide is called saponification—a chemical reaction between a strong base (NaOH) and oils or fats to create soap and natural glycerin.
🔹 Basic ingredients in handmade soap:
Plant-based oils and butters (like olive, coconut, shea, or cocoa)
Sodium hydroxide (NaOH) diluted in water or herbal infusion
Natural additives (clays, herbs, botanical extracts)
Essential oils for scent and therapeutic properties
Basic saponification formula:
Oil + Sodium Hydroxide + Water = Soap + Glycerin
3. Benefits of Cold Process Soap
Cold process is one of the most respected techniques in natural skincare, as it preserves the nutrients in the oils and retains the natural glycerin, offering many benefits for the skin.
1. 100% Natural and Free from Harsh Chemicals
Unlike commercial soaps, which often contain synthetic detergents and artificial preservatives, cold process soaps use only natural ingredients—perfect for sensitive skin.
2. Deep Hydration
This method retains natural glycerin, a humectant that helps lock in moisture and prevents dryness.
3. Gentle Cleansing Without Disrupting the Skin’s Natural Barrier
Thanks to its mildly alkaline pH, cold process soap cleanses without stripping the skin of its natural oils, keeping it balanced and healthy.
4. Eco-Friendly and Sustainable
These soaps are biodegradable and free of sulfates and phosphates, making them a planet-friendly option. Plus, being solid, they eliminate the need for plastic packaging.
5. Customization and Therapeutic Benefits
Handcrafted soaps can be enriched with ingredients like:
Oats and honey for sensitive skin
Activated charcoal for oily and acne-prone skin
Pink clay for deep cleansing and revitalizing effects
4. Myths and Truths About Sodium Hydroxide in Soap
Myth: “Sodium hydroxide is dangerous and remains in the final soap.”
Truth: It’s not dangerous when handled properly, and there's no NaOH left in the final product—only soap and glycerin.
Myth: “Handmade soaps don’t cleanse well.”
Truth: Rich in oils and glycerin, they cleanse effectively without drying out the skin.
Myth: “All bar soaps are the same.”
Truth: Cold process soaps are very different from industrial soaps, which often contain synthetic detergents.
Conclusion
Sodium hydroxide is an essential ingredient in the making of handmade soap—it allows oils to become soap through saponification, without leaving any residue in the final product. Thanks to the cold process method, natural soaps offer a healthy, moisturizing, and eco-conscious alternative for skin care.
Have you tried cold process soap? Discover the difference and give your skin the care it deserves!