There are a few things that were made during the fourteenth century that make me wonder why people thought that adding two (or more) specific things together would make something that they could use. For example, medieval ink was made from water, ground oak apples, gum and a rusty nail. I can understand why they thought the first three ingredients might work, but the addition of the rusty nail baffles me. Did someone drop it into the mix by accident or did he add it with some understanding of what might happen?
It’s the same thing with soap. Why would anyone think that adding lye to olive oil, or tallow (rendered animal fat) if you were making it in England, would make something you could wash with?
It makes sense that people thought of lye (in this instance produced from potash) as a cleaning material. I mentioned last week that lye was used to bleach linen. It’s a caustic solution, though, and not the first thing that would come to mind when you’re thinking about cleaning your skin.
I should add that there are different types of lye, dependent on the type of plant involved. Lye was produced by mixing water with the ash of plants (usually wood, but other plants were also used), allowing it to stand for a while and then pouring off the water. The water was evaporated to concentrate the liquid and then added to the oil/fat.
Soap was used for washing clothes and, to a lesser extent, bodies. Castile soap was the best quality soap available. As its name indicates, it came from Spain. It was made with olive oil and local potash. It came in hard cakes and was less caustic than soaps made in countries further north. It cost about 4d a cake, about two-thirds of a day’s wages for a skilled labourer in England. The white version was for cleaning the skin and the black version was for cleaning cloth. Similar types of soap were eventually made in Italy and Provence when they began importing soda ash from Egypt and Syria.
In England softer, more liquid soaps were made using tallow. They were white, grey and black and were used for cleaning cloth. They were fairly caustic, leaving washerwomen with blistered hands and legs.
Not surprisingly, for most people washing their skin meant using nothing more than water.