Alan Schrank, age 10, of Sioux City, Iowa, for his question:
How do they make soap?
The pioneer woman made her soap in a kettle over a campfires A modern factory can brew more than a 100 tons of soap in a single batch, all done by machinery. Modern soap recipes are more exact and, the ingredients are finer. But the basic method of making soap has not changed much since pioneer days. In fact, it has not changed much since Roman days. A soap factory was found in the ruins of Pompeii, along with bars of soap.
You can make a simple batch of soap for yourself to see how this basic recipe works. Wait until Mother has a very greasy iron skillet in the kitchen, Ask her to clean it this special way. Place a lump or two of washing soda in the fatty grease, add water and bring the mixture to a boil.
The slippery, bubbly, dirty mess is soap. It is messy because of all the charred remains mixed with the grease. But notice how it cleans the pan. It has loosened the caked dirt and you can now rinse it all away. This way, you actually made a simple batch of soap.
The soda in your recipe is an alkali. The grease is ‑. fatty acid. When an alkali is boiled with a fatty acid, the result is soap. The pioneer woman saved the waste kitchen fats for her fatty acid. For alkali she used potash. She got the potash by pouring water through wood ashes, This potash water and the waste fats were boiled together to make soap.
This recipe makes soft soap. Brine, or salty w titer is added to the brew to turn it into hard soap. The proportions of acid, and alkali must be dust right. Too much fat makes a greasy soap. Too much alkali burns the skin, It was not easy for the pioneer woman to balance her ingredients exactly.
Modern soap factories, however, balance their ingredients to perfection. The fatty acid ingredient is a fine, pure material. It may be olive or coconut oil or the oil from cottonseed or soya bean, The various alkalis used are too used are too gentle to burn the skin, iis in the simpler recipes, these two ingredients, a fatty acid and an alkali, are boiled together. They may be fed into a vat four stories high and boiled on and off for 11 days.
The mixture is then beaten smooth with a paddling machine. The smooth mixture is then poured through granite rollers which are kept cool by running water. The soap begins to 'set. It comes out in a flat sheet and goes to more rollers which chomp it up into chips. The flakes are pressed into molds and cut into cakes.
A never method. using centrifugal force has been in use in some factories for the past ten years. It can do the whole job in a few hours. Various things are added to the basic recipe to make different kinds of soap. Rosin is added to most laundry soaps to give more lather. Soaps for cutting heavy grease often contain naphtha or kerosene. Perfume is added to fancy toilet soaps and scouring soaps contain scouring powder.