It is recorded that Babylonians were using soap as early as 2800 B.C.E., although it is possible that soap was discovered before then. The Babylonians used soap to clean wool fibers before spinning into cloth. It was not until later that some cultures used soap for bathing. The Romans and Celts also used soap. A soap making factory, complete with bars of soap, was discovered in the ruins of Pompeii.
Soap Making Ingredients
Saponification is the chemical reaction that takes place when soap ingredients are mixed.
- water
- animal or vegetable fats and oils (or both)
- lye
Lye, also called caustic soda, is a necessary ingredient in the soap making process. If no lye is used in the recipe, the end result is not soap. Caustic soda occurs naturally when water drips through ashes, such as the wood ash left over after a campfire.
Soap is not detergent; soap and detergent are different substances and should not be confused with each other.
Colonial Soap Making
In Colonial times, the fats from meats and livestock were saved and boiled down to render tallow. Tallow is the cleaned animal fats and used in both candle and soap making.
Colonists would save all of the wood ash left over from cooking and heating the home. They placed it in bins with a small hole in the bottom, and another bucket underneath. By pouring water over the ash and allowing it to slowly leach through, the liquid that dripped into the lower bucket was caustic lye.
Soap making was a smelly business. Women would set up a large pot outside and pour water and the caustic lye liquid into it along with animal fats from butchering and cooking. There were no recipes to follow and the measurements were imprecise. The women would boil the foul-smelling mixture all day. To tell if the mixture was no longer caustic, they would throw a chunk of potato into the pot. If the potato floated well, it was finished. Another test was to put a tiny drop on the tip of the tongue to see if the mixture still had a caustic bite.
Colonial soap was a soft, liquid soap. The addition of salt, if desired, would cause the mixture to firm up into bar soap. (Salt was expensive so people used soft soap.) The lye used today is sodium hydroxide, a salt, and creates hard bar soap.
Modern Soap Making Recipes
Today's soap makers use quality-controlled ingredients and consistent methods and recipes for cold process soap making. Castile soap is soap made with pure olive oil and no other oils or fats. There are also numerous vegetarian and vegan soap recipes available today.
Soap makers choose between making a batch of soap once, or hand-milling soap to add special ingredients.
When using the first method, the soap maker will pour in, for example, a cup of lavender flowers after the mixture on the stove is ready to be poured into soap molds. In modern soap making recipes, the liquid soap is still caustic at this point. Therefore, the lye in the mixture may weaken the efficacy of the lavender in the soap.
Hand-milling soap involves waiting for the soap to cure in the molds, which can take a week or two. When the soap is no longer caustic, the soap maker grates the soap and melts it back down with a little water. She then pours the cup of lavender flowers into the soap and pours the soap into molds to dry and harden.
Whichever way it is made, natural soap made with simple ingredients has been used by civilizations for centuries.
More on the history of soap making.
