Myth #1: It's Harsh

Soap in Pioneer Days Was Harsh

Soap made during the pioneer days was indeed harsh, as my husband’s older sisters can attest. In fact, when one of them heard I was about to start making soap she approached me to tell me that if I was going to make lye soap, it’d be too harsh for bathing. I knew she had been using commercial lye soap for years but didn’t realize it simply due to how ingredients are listed in the INCI names.

Why was it harsh?

• The process of making lye back then involved leaching soda ash from hardwood ashes with rainwater, a tedious and labor-intensive task. The challenge was that the strength of the lye solution varied from batch to batch.
• They didn’t have a standardized way of testing it. Instead, they used tests like floating an egg or dissolving a feather in the solution. These tests helped determine whether the solution was strong enough to make soap (source). While this method helped confirm soap-making potential, it didn’t indicate how strong the lye solution was. 
• There was no test to indicate how much lye was needed per pound of animal fat.
• These uncertainties were problematic.
• Soap was generally made only once or twice a year so trial-and-error was slow.

The ability to calculate the right amount of lye per fat didn’t come until the 1880s, with the discovery of saponification (SAP) values for various fatty acids (read about this discovery, click here). Today, we have uniform sodium and potassium hydroxide, along with calculators to tell us exactly how much lye to use for each fat in a recipe.