Soap Making and Safety
Updated: Apr 15, 2022
Soap making isn't rocket science, but it is chemistry. You have to understand the interactions between ingredients. You have to know how much oil to formulate or how certain natural ingredients will change colour in that solution. Each soap begins with a very very specific formula that is carefully calculated to include sodium hydroxide. If the formula requires .032oz of a certain oil, that doesn't mean .05 or .02 - it has to be exact.
Speaking of sodium hydroxide (lye), it is impossible to make soap without it. All true bars of soap are made with sodium hydroxide (potassium hydroxide is used for liquid soap). If your bar doesn't have this ingredient, then it's basically detergent. How can you tell? Look for any oils like sodium cocoate, sodium olivate or the word saponification. This means the oils have been mixed with lye to create the soap.
The cold process way of making soap involves using very cold distilled water in exact amounts and carefully adding the sodium hydroxide to that cold distilled water in exact amounts. NEVER the other way around. If you were to add water to sodium hydroxide.....kaboom.
Sodium hydroxide is caustic. It doesn't play well with metals like aluminum (it creates hydrogen gas) and it's dangerous to breathe the fumes. It can burn your skin and kill you if accidentally swallowed (not that I'm tasting lye! but kiddos and pets should never be around) When I make my lye solutions, I wear a mask, protective eye gear, gloves, long sleeves, pants, shoes and make sure the ventilation is on. You might say, I need my own PPE. You'll notice a more serious looking mask in the picture below. I sometimes use this one if I'm making many batches in one day, otherwise a basic mask is fine.
Once the lye is stirred gently, an exothermic reaction occurs and the cold water instantly becomes very hot. It changes from a cloudy to clear solution and also becomes cooler after 15-30 minutes or so. Once it reaches a certain temperature, it can be carefully mixed with the oil solution mixture, and then colours and scents are added.