Tips for Understanding the Properties of Chemicals to Make Soap - Soapmaid

Tips for Understanding the Properties of Chemicals to Make Soap

Making soap at home is a rewarding and creative process, but it requires a solid understanding of the properties of the various chemicals involved. The right ingredients can elevate your soap from basic to luxurious, while the wrong ones can result in a product that's less than ideal. 

Today, let’s look into the properties of some essential chemicals to make soap, such as sodium hydroxide and caustic soda, and explore how they contribute to the soap-making process.


The Essentials of Soap Making: Sodium Hydroxide and Caustic Soda

Sodium Hydroxide (NaOH), also known as lye, is a fundamental ingredient in the soap-making process. This powerful alkaline compound is crucial for the saponification process—the chemical reaction that occurs when fats or oils come into contact with an alkali to produce soap.

Caustic Soda, another name for sodium hydroxide, plays the same essential role. 

When you buy sodium hydroxide for soap making, you are essentially purchasing caustic soda. This compound is known for its effectiveness in breaking down grease and dirt, which is why it is a staple in both commercial and homemade soap recipes.


Why Sodium Hydroxide and Caustic Soda are Essential

Both sodium hydroxide and caustic soda are integral to the soap-making process for several reasons:

  1. Saponification: The primary role of sodium hydroxide is to react with the fats or oils used in your soap recipe to create soap and glycerin. This reaction is what turns liquid oils into a solid bar of soap.
  2. Cleansing Power: Sodium hydroxide-based soaps are excellent at cleaning because they effectively break down oils and grease, making them ideal for removing dirt and grime from the skin.
  3. Customisation: By adjusting the amount of sodium hydroxide, you can control the hardness, lather, and conditioning properties of your soap. This allows for a high degree of customisation in your final product.


Safety First: Handling Sodium Hydroxide and Caustic Soda

While sodium hydroxide is an essential chemicals to make soap, it is also a highly caustic substance that requires careful handling. Here are some safety tips to keep in mind:

  • Protective Gear: Always wear gloves, goggles, and long sleeves when handling sodium hydroxide. This will protect your skin and eyes from potential burns.
  • Ventilation: Work in a well-ventilated area to avoid inhaling fumes, which can be harmful.
  • Accurate Measurements: Use precise measurements to ensure the correct balance of ingredients, which is crucial for safe and effective soap making.


The Role of Other Chemicals in Soap Making

While sodium hydroxide is the star of the show, several other chemicals play supporting roles in creating high-quality soap. Let’s take a closer look at a few of these:


Potassium Hydroxide

Used primarily in the production of liquid soaps, potassium hydroxide (KOH) provides similar benefits to sodium hydroxide but results in a softer, more fluid end product. Liquid soaps made with potassium hydroxide are perfect for hand washes, shampoos, and even cleaning products.



Glycerin is a by-product of the saponification process and is known for its moisturising properties. In many commercial soap productions, glycerin is removed and sold separately, but in homemade soap making, it remains in the soap, providing added skin benefits.


Stearic Acid

Stearic acid is used to harden soaps, giving them a more robust and longer-lasting form. It also helps stabilise the lather, ensuring your soap produces a rich and creamy foam.


Citric Acid

Citric acid is often added to soap recipes to help balance the pH levels and chelate metal ions, which can improve the soap's texture and longevity. It also acts as a mild preservative, helping to extend the shelf life of your soap.


Combining Ingredients: The Perfect Soap Recipe

Creating the perfect soap recipe involves more than just mixing sodium hydroxide with oils. The right combination of ingredients can make a significant difference in the quality and characteristics of your soap.


Base Oils

The choice of base oils is crucial as they determine the soap's moisturising properties, hardness, and lather. Common oils used in soap making include:

  • Olive Oil: Known for its moisturising properties and gentle cleansing action.
  • Coconut Oil: Provides excellent lather and hardness, but can be drying if used in excess.
  • Palm Oil: Adds hardness and a creamy lather, often used in combination with other oils.
  • Shea Butter: Adds moisturising properties and a luxurious feel to the soap.



Additives such as essential oils, colourants, and exfoliants can be used to enhance the sensory and aesthetic qualities of your soap. For example:

  • Essential Oils: Provide natural fragrance and therapeutic benefits.
  • Colourants: These can be natural (like clays and botanicals) or synthetic, adding visual appeal to your soap.
  • Exfoliants: Ingredients like oatmeal, poppy seeds, or coffee grounds can add a gentle scrubbing effect.


Crafting Your Soap: Step-by-Step Guide

Now that we’ve covered the essential chemicals and ingredients, let’s walk through the basic steps of making soap at home.


Step 1: Preparation

  • Gather Ingredients: Ensure you have all the necessary ingredients and equipment, including a scale for precise measurements.
  • Safety Gear: Put on your protective gear and ensure your workspace is well-ventilated.
  • Moulds: Prepare your soap moulds by lining them with parchment paper or using silicone moulds.


Step 2: Mix the Lye Solution

  • Measure Water: Measure the required amount of distilled water into a heat-resistant container.
  • Add Sodium Hydroxide: Slowly add sodium hydroxide to the water (never the other way around) and stir until fully dissolved. This mixture will heat up quickly, so handle it with care.


Step 3: Combine Oils and Lye

  • Melt Oils: In a separate container, melt your solid oils (like coconut oil) and combine them with your liquid oils (like olive oil).
  • Mix: Once the oils and lye solution have cooled to around the same temperature (usually between 37-43°C), slowly pour the lye solution into the oils while stirring continuously.


Step 4: Trace

  • Blend: Use a stick blender to mix the oils and lye solution until you reach "trace," the point at which the mixture thickens and leaves a trail when dripped from the blender.


Step 5: Additives and Pouring

  • Add Additives: Once you reach trace, add any essential oils, colourants, or exfoliants to your soap mixture and stir well.
  • Pour: Pour the mixture into your prepared moulds, tapping the moulds gently to remove any air bubbles.


Step 6: Curing

  • Cover and Insulate: Cover the moulds with a towel to keep the soap warm as it begins to set.
  • Cure: Allow the soap to cure in the moulds for 24-48 hours, then unmould and cut into bars. Let the bars cure in a cool, dry place for 4-6 weeks to complete the saponification process and evaporate excess water.


Crafting Quality Soap at Home

Creating soap at home is a rewarding hobby that allows for endless creativity and customisation. By understanding the properties of the essential chemicals involved—particularly sodium hydroxide and caustic soda—you can craft high-quality soaps tailored to your preferences and needs.

Whether you're just starting out or are an experienced soap maker, always prioritise safety and precision. The right balance of ingredients and careful handling of chemicals will ensure a successful soap-making venture every time. For those looking to get started, remember that you can buy sodium hydroxide for soap making from trusted suppliers like Soapmaid to ensure you're using top-quality ingredients.


Start Your Soap Making Journey with Soapmaid

Ready to create your own luxurious soaps at home? At Soapmaid, we offer a comprehensive range of high-quality raw materials, including sodium hydroxide and caustic soda. Visit our website today to explore our selection or maybe just buy caustic soda for soap making and start crafting your bespoke beauty products. Happy soap making!

For more information on soap making and to explore our range of products, visit Soapmaid.

Back to blog