Essential oils have been used for thousands of years. We have evidence dating back to Ancient China, India and Egypt of the use of fragranced oils (they’re mentioned in the Book of the Dead).
Frankincense was mentioned in the New Testament of the Bible and lipid residue analysis from archaeological sites shows plant oils were being used throughout history in a range of places such as Ancient Rome and Greece. The Romans used olive oil to get clean by covering their bodies with it then scraping it off with a special scraper. This was commonly done at bath houses.
There is a story that soap was first discovered by Roman women washing their clothes in the River Tiber below where the animals were sacrificed and the animal fat had somehow reacted with the clay in the river.
On the surface, this makes no sense because clay is not a source of sodium hydroxide (lye) and common wisdom says you cannot saponify without it. However, in reality, you could technically saponify with any aqueous alkaline (e.g. one with some water in it), and some types of soil are alkaline (these are almost always clay soils). I would want to do some experiments before being able to say one way or the other about whether this could really work or whether it’s just a nice fairytale about where soap came from.
The practice of putting oils into soap came later. In fact, while solid bars of soap seem old-fashioned to some people, they were only invented in Victorian times. Before this, people had a special jar of liquid gloop that was used for cleaning themselves, and they didn’t use it very often. So if you’re ever reading a Regency romance, when the author has a bath scene and the characters are using a bar of soap, you’ll know they haven’t done their research!
The Victorians were the originators of many of the unpleasant and outright dangerous chemicals that permeate our modern lives, and Victorian soap was no exception. The most popular type of soap was Carbolic Soap, aka Coal Tar Soap, which is about as unpleasant as it sounds.
It was made using the disinfectant carbolic acid, which is a carcinogenic and poisonous substance made from tar. It also has a distinctive ‘disinfectant’ scent that anyone who went to school in the 20th century would instantly recognize. Soap doesn’t need to contain any disinfectant to kill bacteria, however (we didn’t understand this back then — germ theory hadn’t been confirmed until Louis Pasteur’s work in 1863 and we didn’t have microscopes yet so couldn’t see them, either), something I will write more on in a separate article.
Soapmaking in Victorian Britain was an industry of mass-production using the cheap and disgusting byproducts of other industries (the standard ingredients were beef tallow, which is the fat that’s been removed from dead cows, carbolic acid, a byproduct of the tar industry, itself a byproduct of the coal mining industry, and sodium hydroxide, still used in soap today).
We tend to see the sodium hydroxide lye as the most dangerous and unpleasant aspect of soapmaking nowadays, but it’s the least awful of the three traditional soapmaking ingredients (fancy killing a cow and stringing it up to drain the fat, anyone? No?).
As a sidenote, tallow was also used for candle making. There’s a pub in York called the Guy Fawkes which I went in a few years ago and I couldn’t breathe while I was in there because it was lit by hundreds of candles. It was really beautiful and atmospheric but the smell of evaporated beef tallow was really sickening because I was vegan at the time.
It’s not clear when the first essential oils were used in soap, although it was only in the twentieth century that essential oil soaps became mass-produced as the New Age revolution of the sixties rejected the artificial byproducts of capitalism that were making people sick and destroying the landscape, and they started to question the way things were. Thanks, hippies! I love that there’s another connection between vanlife and soapmaking in the history of the use of essential oils in soap.