Hey!
It's Kathleen, the Owner and Maker behind West Grove Soaps. Here is my blog post about the scary-but-not-so-scary ingredient in soap... LYE!
A common question is: "Is there lye in your soap? Is it safe?"
The short answer is yes, and yes! I shall explain...
So, what exactly is lye?
Lye, scientifically known as Sodium Hydroxide (NaOH), is an alkali salt. On its own and in its raw form, Lye is a very caustic substance -- meaning it can cause serious burns if it comes into contact with your skin or eyes in its raw form. Ouch!
And I put this in my soap?! Yes! Here's why:
Lye is an absolutely essential ingredient in real bar soap! No lye, no soap. (and that's no lie! Ugh....)
So um... if lye is going to burn you more than a "yo mama" joke, how is it safely used in soap?
This is where the magic of saponification comes in. (I talked about this in my Cold Process soap making post — go check it out if you haven't!)
When lye is combined with oils and butters, a chemical reaction called saponification occurs. The lye reacts with the fatty acids in the oils and completely transforms into a lathery, sudsy butterfly! After 24-48 hours of blending lye with oils, the lye that went in no longer exists and therefore, is not in the end product.
What you're left with is soap and glycerin (Glycerin is a sugar alcohol liquid that draws moisture into the skin. It comes from plant and/or animal fats, and acts as a moisturizing, sweetening, and thickening agent and is frequently used in skincare products.)
What starts as your skins worst enemy, becomes your skins BFF. Classic love story!
This is why the curing phase in Cold Process soap making is so important. During those 4–6 weeks of curing, saponification completes fully and the excess water evaporates, leaving you with a hard but gentle, nourishing soap bar. By the time a West Grove Soaps bar reaches your hands, there is zero active lye remaining.
Curious about store-bought soap?
Many commercial "soaps" you find at big box stores aren't technically soap at all — they're detergent bars made with synthetic surfactants. Real soap, by definition, requires lye. So if a product claims to be soap but says "lye-free," it's either a detergent bar or the lye has already been fully consumed in the saponification process (which is what happens in handcrafted soap!).
Safety First! How do I handle lye safely in my studio?
Even though lye transforms completely in the finished bar, I take safety very seriously when working with lye in its raw form.
Here's how I stay safe in my studio:
- Protective gear always — chemical resistant disposable gloves, safety goggles (shout out to STOGGLES!), and long sleeves are non-negotiable when handling raw lye.
- Add lye to water, never water to lye — this prevents a dangerous, volcanic reaction. Always lye to water!
- Work in a ventilated space — when lye is mixed with water, it releases a lot of fumes. I always work near an open window or with a fan. Most of the time, I put my newly batched lye outside in a safe space to cool down.
- Keep children and pets away — the lye solution gets extremely hot (up to 200°F!) and is caustic until fully saponified.
- Use dedicated soap-making tools — I keep separate containers, spoons, and equipment just for soap making.
The bottom line:
Lye gets a bad rep, understandably so, but it's simply a misunderstood ingredient. In the hands of a careful, experienced soap maker, lye is the key to creating a truly nourishing, all-natural bar of soap. Every West Grove Soaps bar is made with care, cured fully, and safe for your skin!
Thank you for stopping by!
-Kathleen