While Claire in her 1940s life used laundry soap and a basic washing machine, her time traveling life did not have such a luxury. Instead, wash day consisted of lots of drinks, hand washing, and urine production.
Okay, today we have products to remove urine but in the past, urine, believe it or not, was a cleaning agent. In Roman times, pots were placed in alleys along streets specifically for urine or chamber lye collection. These were collected daily and placed in large vats. Soiled clothing was placed in these vats along with some water. To wash the clothes, one would stir them in the urine/water combo with a long wooden rod. Once that was done, an individual whose job it was to wash clothes would climb into the vat and agitate the clothes with their feet. This action mimicked our modern day washing machine.
In the Outlander series though, Claire just happens upon wash day in a village when she was riding to collect rent with the MacKenzie clan. While the women did not have a vat of urine, their use of this liquid appeared to be as a stain remover and/or dye setter for the clothing since it was poured on. To keep the supply coming since fresh urine is best as a detergent, drinking was encouraged and even Claire took a few swigs and a squat over a bucket to do her part.
Today, the idea of cleaning your clothes with urine sounds disgusting and unhealthy but believe it or not, science can easily explain how this works. First, urine has a high ammonia content, which allows it to neutralize dirt and grease that tends to be a little acidic. Once the dirt on the clothes has been neutralized, it is easily removed from the fabric. This neutralizing process not only removes stains but also brightens whites.
What makes chamber lye such a wonderful stain remover and brightener also makes it a useful mordant or substance that binds dye to cloth. Since 1740 clothing dyes were made from naturally found substances, a dye setter had to be used to prevent the colors from bleeding. Urine, in this case, was the answer. The process was simple. Clothing dye is made up of chromosomes, which are little molecules of color. To keep them from being washed away, these color molecules need to be surrounded by a bigger or group of molecules that will protect the color. The ammonia in chamber lye was the perfect mordant that would allow the color to show thru while protecting and binding the color to the fabric.
Today, we have other means by which to whiten whites and brighten colors but one of the top cleaning agents still remains to be ammonia. While the idea of washing your clothes in chamber lye may be revolting, the relationships developed over a dram and dirty clothes were irreplaceable.
Written by: Mindy McIntosh-Shetter