About Lye For information on Potassium Hydroxide or Potash - CLICK HERE

People have been using lye as a detergent or soap for thousands of years!
Up until the 18th Century, the old-fashioned ingredients for making soap were: wood ashes, water, animal fat and salt. This was used all around the globe.

Below are links to Vintage Pamphlets (PDF) showing the many uses, historically, of Lye. The uses of Lye in these vintage pamphlets is for historical review only and may not be safe to be used in the manner indicated in the vintage pamphlet. Lye is a dangerous chemical; and as such, you should be very careful when using Lye.

Note: Download of the pdf files below can take a few minutes depending on your internet connection speed. Once downloaded, you can then view them online or print the pamphlets.


Lye, also known as caustic soda, is the common name for Sodium Hydroxide (NaOH). Lye is commercially used, most commonly, in the manufacture of paper, textiles and detergents. Some common household products that use lye in the manufacturing process are soaps, detergents, oven cleaners and drain cleaners (* Red Devil Lye being the most famous). Pure sodium hydroxide is a white solid which is available in flakes, pellets, beads, granules and also a 50% saturated solution. It is highly caustic and care should be taken with storage and handling. There used to be a product called "Red Devil Lye" available (pure lye) which unclogged drains - this product was 100% lye but has been pulled off the shelves because of storage and safety issues! For more chemical information on lye, check http://en.wikipedia.org/wiki/Lye

Simply described - ashes, soaked and heated in water is the way to make lye. The lye, then mixed with fat, through a process known as saponification, creates soap.The added salt is what hardens the soap.

Lye can be traced back to use in soap as far back as the Babylonians in 2800 B.C.

The Ruins of Pompeii revealed a soap factory together with finished bars of soap. This soap was not used for personal cleansing,,, it was used mainly for cleaning textiles such as wool and cotton in preparation for weaving into cloth.

By the middle ages soap was being used for personal cleansing throughout Europe as well as textile and household cleaning.

The American Colonists brought soap with them when they settled and then, after a while, at butchering times, began to make it for themselves.

Nowadays the electrolytic process is used for making lye. An electric current is passed through a sodium chloride solution which splits the salt molecules into atoms of sodium and chlorine. The sodium atom displaces one of the hydrogen atoms of the water hence forming sodium hydroxide, aka lye, aka caustic soda.

* Note: by 1998 it was estimated that the world production of sodium hydroxide was around 45 million tonnes! A MUCH demanded product Red Devil Lye was withdrawn from the market because of the health risks!
If you wish to purchase lye for homemade lye soap please click here.

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