Pros and Cons:
Making Your Own Lye
Yes, you can make lye from scratch.
Lye making can be a bit of pain, depending on your living conditions. If you've got the space, ashes from your fireplace that would get thrown out anyway, and a burning curiousity to understand what soap-making was like in the days before lye could be delivered to your front door at the click of a button... then, by all means, give it a try.
If (like me!) you're in a tiny apartment with no place to set up a lye making system, no convenient fireplace to plunder ashes from, and little patience for imprecision (such as not knowing the exact concentration of your lye-water)... then you'll probably want to sit this one out.
|Commerical Lye||Homemade Lye|
Lye marketed for soap-making has a high level of purity. Avoid draincleaners, even if labeled "100% lye" (they usually aren't!)
- Precise Concentration
You control the concentration of lye. This allows you to use the easier cold-process method.
Learn how lye was made thousands of years ago.
Do it yourself, and don't worry about where to find lye.
- Use Up Waste Products
If you have hardwood ash on hand (from a fireplace), you can get some use from it, rather than just throwing it out.
You must purchase the lye, and possibly pay additional costs for shipping a hazardous material.
If lye is not locally available, you will need to wait for it to be shipped to you.
|- Raw Materials
Lye may be easier to find then the materials, if you don't have access to ash and straw.
- Unknown Concentration
You can not use this lye for cold-process soap-making (you will need to use hot-process).
- Time Consuming
You'll need to spend several days letting your lye water build up it's potency before it can be used.
- Softer Soap
Lye making produces potassium hydroxide, NOT sodium hydroxide. This creates a softer (or liquid) soap.
You'll need to take proper safety precautions while making lye.
Overall, making your own lye introduces more work to every step of the soap-making process: making lye is more time-consuming than purchasing lye; homemade lye will force you to use hot-process methods, which are more intense than cold-process, and you need to add steps and ingredients to harden your soap at the end.
Which is why I stick with commercial lye.
However, if you really want to know how it's done - for the sake of historically re-enactments or extreme self-sufficiency, here's a basic set of directions to get your started: How to Make Lye.