How To Make Cold Process Soap

What Is Cold Process Soap? Cold process soap is made by combining oils with a lye solution to create soap from scratch through a chemical reaction known as saponification. During this process, the ingredients naturally turn into soap and glycerin without needing additional heat after mixing. Unlike melt & pour soap, which starts with a ready-made base, cold process gives you complete control over the recipe. This allows you to customise everything from lather and hardness to cleansing and skin feel. How Does It Work? Cold process soap making relies on a reaction between oils, water and sodium hydroxide (lye). Once combined, the mixture begins to thicken and eventually hardens into soap. The typical process involves: Mixing sodium hydroxide with water to create a lye solution Melting and blending oils and butters Combining the oils with the lye solution Adding fragrance, colour and other additives at trace Pouring the soap into moulds to set Cutting and curing the bars for several weeks The curing stage is an important part of the process. As the soap cures, excess water evaporates, creating a harder, longer-lasting bar with improved performance. Comparing Soap Making Methods Each soap-making method offers different benefits depending on your goals: Cold Process: Full control over ingredients and formulation, but requires curing time Melt & Pour: Fast and beginner-friendly using a pre-made base Hot Process: Cooked during production to speed up saponification with a more rustic finish For brands focused on ingredient transparency, custom formulations and premium products, cold process is often the preferred choice. Why Formulation Matters One of the biggest advantages of cold process soap is the ability to tailor recipes using different oils and butters. For example: Coconut oil boosts cleansing and lather Shea butter improves conditioning Olive oil creates a milder, longer-lasting bar By adjusting your formulation, you can create products that suit your brand identity — whether that’s a rich luxury bar, a gentle facial soap or an everyday cleanser with a creamy lather. Click to read the full Beginners Guide To Cold Process Soap