There is a lot of folklore surrounding homemade lye soap. Most stories came from our grandparents who were very familiar with lye soap making. One of the most common tales was that it was a cure for poison ivy. From others we heard that it was so harsh it would take your skin off. Because the same bar with which we bathed, was also used to for laundry, we were also told, "nothing cleans clothes like lye soap".
We might not need a cure for bed mites nowadays, there are still many suffering from such common skin maladies as eczema and psoriasis. It has been reported that lye soap relieves psoriasis the symptoms of these afflictions in relatively short order. It may just be that discontinuing the use of store bought soap, which is laden with chemicals and preservatives was enough to start the healing process.
The difference between lye soap that was made by our ancestors and lye soap today is that we have exact measurements that will make the desired bar much more easily. You could choose either a harsh, lye heavy bar or a milder fat heavy bar, easier on the skin and with all of the soothing qualities desired in soap today. Making soap in years past was a very inexact science where the soap maker, made adjustments on the fly according to such strange measurements as, does an egg or potato float in the lye water mix? This was the test of lye to water proportion in colonial soap making. Also the mixture was sometimes boiled for between four and twelve hours during which plenty of evaporation occurred. It was impossible to determine exactly how much water had evaporated and many times during the process water-lye solution would be added to the mix if deemed necessary.
I have seen many an old fashioned lye soap recipe that is described as and similar to;
1 box of lye
4 lbs of lard
20 ounces of water
Can this type of old fashioned recipe still work? Sure it can, except for the fact we don't know how much a box of lye weighs. If we use a lye calculator we can find right amount of lye to add to the recipe. The sap value for is 138. Multiply that by the total number of ounces of lard (64) and we get 8.832. This is the amount of lye, in ounces we would need to turn the lard into soap. Another way to say this is, it would take approximately 8 ounces of lye to saponify 64 ounces of lard. If you use slightly less lye you will attain a softer bar and if you increase the lye you will attain a harsher bar much more like the one Grandma used to make. Soon, after experimenting for a while, you will find one that suits your tastes perfectly.
After some evaluation the true value of lye soap is the fact that it is homemade from natural ingredients that are part of our collective heritage. Yes, the soap has many attractive qualities, but would it be so appealing if we did not make it ourselves? Maybe, though the fact that we have made it with our own hands is sure to add to the universal appeal of a homemade natural product.