Discovery of 9th Century Soap Factory in Israel Sheds Light on Ancient Trade

The Israel Antiquities Authority (IAA) announced the dis­cov­ery of a 1,200-year-old olive oil soap fac­tory near Rahat, a Bedouin city in south­ern Israel.

This is the old­est known soap fac­tory in mod­ern-day Israel and one of the world’s ear­li­est exam­ples of solid soap pro­duc­tion.

According to IAA, the fac­tory was found inside the house of a wealthy fam­ily. The archae­ol­o­gists believe that the family’s afflu­ence was derived through the sale of the olive oil soap.

“This is the first time that a soap work­shop as ancient as this has been dis­cov­ered, allow­ing us to recre­ate the tra­di­tional pro­duc­tion process of the soap indus­try. For this rea­son, it is quite unique,” said Elena Kogen Zehavi, the IAA exca­va­tion direc­tor. ​“We are famil­iar with impor­tant soap-mak­ing cen­ters from a much later period – the Ottoman period. These were dis­cov­ered in Jerusalem, Nablus, Jaffa, and Gaza.”

Olive pits found at the dig and chem­i­cal analy­ses show that this 9^th-cen­tury soap fac­tory used olive oil as its base. The olive oil was mixed with ashes from salt­wort plants, which are com­prised of potash salts and water.

According to the IAA, the result­ing mix­ture was cooked for seven days before being allowed to cool harden for another 10 days. After hard­en­ing, the soap was cut into bars and left to dry for an addi­tional two months.

Kogen Zehavi told the Times of Israel that this method of pro­duc­tion is still being used by olive oil soap pro­duc­ers in Nablus. The Palestinian city has been a cen­ter for olive oil soap pro­duc­tion since at least the 10^th cen­tury.

This process took a while, but once com­pleted, the olive oil soap was eas­ier to ship and sell. Kogen Zehavi added that the soap was a valu­able export com­mod­ity at the time. From Egypt to Baghdad, wealthy peo­ple bought soap as quickly as soap mak­ers could pro­duce it.

The mayor of Rahat, Fahiz Abu Saheeben, added that the dis­cov­ery of the 9^th-cen­tury fac­tory fur­ther demon­strated the deep ​“Islamic roots” of the city.

Scholars have long sup­posed that the 9^th cen­tury marked a regional down­turn in cul­ture and eco­nom­ics. However, the soap fac­tory, among other recent dis­cov­er­ies, sug­gests a great deal of trade and com­merce con­tin­ued, with much of that trade being in olives and olive oil prod­ucts.

After the Islamic con­quest, wine pro­duc­ers were largely out of work. However, fol­low­ers of Islam view olives and olive oil favor­ably and regional pro­duc­tion of both increased con­sid­er­ably.

Sometime in the 8^th cen­tury, Islamic chemists mas­tered the cre­ation of hard soap. At the time, Europe was using greasy soap lotions made with lard to clean clothes and floors. In place of ani­mal fat, Islamic soap mak­ers used olive oil. These new odor­less soaps could also be used for per­sonal hygiene.

• Ha’aretz
• Times of Israel
• Bulletin of the American Schools of Oriental Research