Quick Answer
Common oils that create hard bars in cold process soap include coconut oil, palm oil, palm kernel oil, and cocoa butter. They contribute to the soap's hardness due to their high levels of saturated fats.
Hardening Factors in Soap
When it comes to creating hard bars in cold process soap, several factors come into play, but the primary contributor is the type and amount of oils used. Fats with high levels of saturated fatty acids (SFAs) are more likely to create hard bars. SFAs provide structure and contribute to the soap’s rigidity.
Saturated Fats and Soap Hardness
Coconut oil, for instance, contains approximately 90% SFAs, making it an excellent choice for creating hard bars. Palm oil and palm kernel oil, with their high SFA levels, also contribute to soap hardness. The ideal percentage of coconut oil in a recipe can range from 20% to 40%, depending on the desired level of hardness.
Other Contributors to Soap Hardness
Cocoa butter, another saturated fat, can also contribute to soap hardness, although it’s generally used in smaller quantities due to its high cost and potential for soap separation. When using cocoa butter, it’s essential to maintain a balanced fatty acid profile to avoid creating a soap that’s too hard or brittle. A general rule of thumb is to use 5-10% cocoa butter in a recipe, depending on the desired level of hardness and moisturizing properties.
Find more answers
Browse the full Q&A library by topic, or jump back to the topic this question belongs to.