Lye , also known as caustic soda, is defined as a strong alkaline liquor rich in potassium carbonate leached from wood ashes and essential in making soap and for washing.
The ancient use of lye for soap-making and as a detergent is the origin of the English word, deriving from Proto-Germanic *laugo and ultimately from the Proto-Indo-European root *leue-, “to wash.”
Sodium hydroxide is commonly the major constituent in commercial and industrial oven cleaners and clogged drain openers, due to its grease-dissolving abilities.
Sodium hydroxide is VERY caustic and must be used with care. It can burn holes in clothes and leave burn marks on skin.
Lye looks like water once it is dissolved in water, so you must take every precaution and keep it away from kids and pets.
Never stand directly over lye when mixing it with water. It will release fumes into the air for about 30 seconds. These fumes can cause a choking sensation in your throat, but are not harmful unless you inhale them directly.
Keep vinegar handy. Vinegar, an acid, counteracts lye if you do get burned.
Lye mixes with oil and saponifies, or becomes soap. At first, you have lye, water, and oil. Then the curing process begins and after a few days the lye, water, and oil is transformed into soap. At the end of the curing process, perhaps 3-4 weeks (sometimes more), there is no lye left in the soap, no oil, and no water. What is left behind is pure soap with nothing of the original ingredients left behind. (https://www.diynatural.com/sodium-hydroxide-lye/)
