LET’S TALK ABOUT TRADITIONAL SOAPS
Introduction
As we learned in previous blog posts, every culture eventually developed their own form of soap. Traditional soaps were cooked hot. Some were cured for months on end. Some for only two to four weeks. Geography determined the ingredients, but the concept was the same throughout the world. Wood ash or cocoa pod/plantain skin ash leached through water, plus fats and oils, cooked until paste-like consistency. Allowed to harden. Shaped. Boom. Soap. Today, we are going to take you through three lineages of soap, from the original Aleppo soap, to Marseille Soap and end in West Africa where lye takes a different shape, but similar process.
Aleppo
Olive Oil, Laurel, Lye. Three ingredients, the backbone of Syria’s “green gold”. Legend has it Cleopatra of Egypt and Queen Zenobia of Syria used this soap, but those claims are not verified. What isn’t up for debate is the meticulous nature of production. Cooked only in cooler months, olive oil and water are added into an in-ground vat. Lye is added. Then the underground furnace is stoked, and the mixture is brought to around 200 degrees Fahrenheit. This large vat of saponification could cook for three days. When the soap paste is sufficiently hot, laurel oil is added. Stirring continues. When the consistency is perfect, the soap is then poured onto the floor and allowed to set. As it is setting, the workers, the soapmakers themselves, in wooden shoes even out the sheet of soap. Once the green gold is hard, it's time to stamp, then cut, again all by hand. In ancient times stamped and cut by hand, and today, stamped and cut by hand. This soap is aged for six months. Minimum. Oftentimes longer. This simplicity. This attention to detail is what made Aleppo one of the original centers of soap.
Marseille
Savon de Marseille. Stamped with “72%”. The grandchild of Aleppo Soap. Soap with legal decree behind it. The 1688 Edict of Colbert specified no animal fats, and Marseille soap had to be made in Marseille. Four simple ingredients. Olive oil (at minimum 72%), water, sea salt, soda ash (the alkali source). This soap began its journey in the 14th century, and would not exist without the backbone Aleppo soap provided. By the 17th century, Marseille was a preeminent soap capital.
Now some chemistry because it's what makes these soaps what they are. The process begins with a kettle cook that could last for two weeks. The salt here does something interesting. Once the soap is cooked, the salt is added, and a process of “graining out” begins. Aleppo soaps and historical jabón de Castilla also did this. The graining out process is a chemical reaction where the salt reduces the solubility of the soap, forcing it to float at the surface. The impurities, the glycerine and excess lye remain in the murky water below.
African Black Soap
Now, what happens if instead of using sodium hydroxide, potash is used? Instead of using wood of coastal shrubs, cocoa pods and plantain skins were used? The ashes leached through water, and cooked in a kettle with fats? Well, you get a softer soap. In this case, black soap made in West Africa. That’s because the potash is actually a form of lye, but the ions are larger than sodium hydroxides so the soap structure is looser. When combined with palm kernel oil and shea butter cooked for a few hours, or even a whole day, the result is soap the texture of cookie dough. The process can be tumultuous though. The strength of the lye is determined more by feel than numerical measurements. The knowledge is passed through the matriarchal line. The cocoa pod ash has to be burned to the right consistency. Then leached for the proper amount of time. The cook can’t be too hot, or the soap will burn. The cook can’t be too cold, or the soap won’t saponify. When the soap is removed from the kettle, it is molded into blocks, bricks or spheres, and allowed to rest for two weeks. This soap is made with a slightly different chemistry than the harder bars, but it is still very cleansing, and gentle on the skin.
Conclusion
The knowledge of soap is an ancient one. From soft soaps, to hard bars, these traditional soap makers have set the stage for all those that followed suit. Through trial and error, lye burns and scalding hot soap batter, soap was shaped into what we know today. Fall down 1,000 times, get up 1,001, then just leave well enough alone.