How to make soap without lye (your questions answered)

An introduction to what natural soap is and how you can make it at home—both with and without handling lye.

As a soap maker, one of the most common questions that I get asked is how to make soap without lye. It’s an understandable one since a lot of people are afraid of using sodium hydroxide or potassium hydroxide (lye) and are concerned about “chemicals.” Others want to make soap at home with the kids and don’t want to worry about accidents.

Over the past six years, I’ve run in-person beginner soap making workshops, and I can assure you that if you want to make cold-process soap, you can. Many anxious people have crossed my doorstep, and each one has left not only feeling confident but with handmade soap in their hands. I want you to have that experience too, but to understand the answer to how to make soap without lye, you need to understand what soap is.

What is soap anyway

Soap is described in chemistry as a salt of a fatty acid and a surfactant. It’s a substance that pulls oil and grime from our skin, pans, or clothing, and helps it to rinse away in water. In essence, soap makes water wetter.

Don’t get nervous over the word chemistry, either. We rely on chemistry for life! To make soap, you do need to understand a little of what happens, and if you find a passion for soap making, learning the chemistry of customizing and formulating soap recipes will come after. To make your first batch, though, just follow my instructions, and you don’t need to worry about the science stuff.

You make natural soap by saponifying oils and lye. This begins to happen when the soap comes to ‘trace’

Soap vs. detergent

Most of the ‘soap’ that you’re probably used to using isn’t real soap at all. Most body washes, shampoos, kitchen soap, bars of soap, and liquid hand soap are actually detergents. Detergents are also surfactants, but they are not soap. Instead, they’re made using manufactured compounds such as Sodium Lauryl Sulfate (SLS) – the stuff that makes toothpaste foam and cleans your teeth. For most people, it’s not harmful, but detergents are also not natural.

Even the bars of soap that you grew up with or see for sale in shops could be a detergent. The best way to know is to look at the packaging. If you can’t find the word soap on the label, then it’s not soap. If it says ‘beauty bar’ or something like that, then it’s probably a detergent. Laws dictate what manufacturers can put on their labels, but they’ll do their best to fool you.

Batches of handmade cold-process soap decorated with flower petals

The invention of soap

No one knows when soap was invented, but it was thousands of ago. Scientists speculate that people discovered it by accident when hot oil from a cooking pot fell into an ashy puddle underneath. Perhaps the person cooking spotted a weird new substance and started experimenting with it and trying to see if they could make it again. Remember that these three ingredients are essential to the most primitive soap making – fat, ash, and water.

So what happens to transform it into soap? Wood ashes, when leached in water, create Potassium hydroxide – a type of lye. If it’s cooked with fat, it breaks apart the molecules apart and bonds with them. This process is called saponification and leads to soap being it’s own natural chemical compound. A special homemade substance that keeps our bodies and homes clean and hygienic.

Caustic potash, also called potassium hydroxide, is what you use to make liquid soap

How to make soap (real soap)

We don’t use wood ashes to make soap anymore, and if you come across a tutorial telling you otherwise, please don’t try it. There is no way for us to know how much lye is in the final liquid from wood-ash leaching so it may be weak, and won’t make soap, or very high, and it will burn your skin. Instead, we use Potassium hydroxide and Sodium hydroxide from soap making suppliers.

You can use these types of lye to make soap from scratch using the cold-process or hot-process methods. It may also be used to create some kinds of melt-and-pour soap.

Sodium hydroxide is what you use to create bar soap

Types of Lye

Potassium hydroxide is used in a hot-process method to make a kind of soap paste. You can dilute it in water to make a fabulous natural liquid soap, though it’s not a quick project. Sodium hydroxide is the lye you use to make bar soap. No other substances can be used in place of either sodium hydroxide or potassium hydroxide to make soap.

When you introduce lye to fats and oils, it breaks the molecules apart and bonds with them, creating a new compound – soap! You can watch it happen when you’re making soap from scratch. The oils and lye begin liquidy then start turning opaque and thick. When soap comes to ‘Trace’, it’s the sign of a successful natural chemical reaction. Most of the lye is used up at that point, but after two days it’s usually always transformed into soap. That’s why natural soap does not contain lye when you use it. That lye is now soap.

On an aside, I use food-grade sodium hydroxide – though it’s caustic and yes, used to clean drains, it’s also important in some parts of the food industry. Pretzels are dipped into a weak lye solution before being baked, and lye is even used in processing cocoa and chocolate, among other things. If bakers aren’t afraid to use it in making food, you shouldn’t be worried about using lye to create gentle, handmade soap.

Melt and pour soap arrives in a solid form that you melt, customize, and mold

Can you make soap without saponification

If all this is sounding complicated to you now, you might be asking if you can make soap without saponification. The short answer is no – all true soap begins as fats and lye. If you want to make soap from scratch, then you need to saponify fats and lye to create it. There’s a way that you can skip having to handle lye, though.

Here’s my recipe for No-lye Sensitive Soap

How to make soap without lye

The main way that you can make soap without handling lye is by using melt-and-pour soap. It’s already been through saponification (oils reacting with lye) and is safe to use and handle straight out of the package. All you do with it is melt it, add your scent, color, and other additives, then pour it into molds. It’s easy-peasy and a quick project and fun for both adults and littles. There’s even an incredible book that’s come out with all kinds of natural ideas to color, scent, and customize melt and pour soap.

Melt-and-pour soap comes in all types. Clear glycerin soap, creamy goat milk soap, palm-oil free, the list goes on. Melt-and-pour soap can also be a detergent, so watch out for the ingredients. I don’t think it’s cheating to use m&p, and it’s a great way to begin your soap making journey. I even have a recipe for you to try.

Another way to make soap without lye is to use plants rich in saponins. All you need to do with them is warm the roots, leaves, and fruit of these plants in water and they create all-natural cleaner for home and health.

See how the rebatching method works in this parsley soap recipe.

Rebatching

There’s kind of a second way to make soap with lye. Soap makers tend to have a stash of ugly soap – basically, batches that didn’t turn out the way you’d planned. One way that we make it pretty is by rebatching it. It involves shredding the bars down, mixing with a little water, and melting them to a kind of paste. Afterward, you can add color, scent, etc. and push the soap batter into molds. You do need to make soap from scratch before, though, so that may defeat the purpose of your visit.

Can you make soap without chemicals

If you’ve read this piece through, you’ll know that all real soap is made, one way or another, with lye — but also, that handmade soap doesn’t contain lye. If it’s made correctly and with a good recipe, then handmade soap is gentle and can be a hundred percent natural. You can’t avoid lye if you want to make soap from scratch. If you hear otherwise, that source is incorrect.

As for handling ‘chemicals,’ honestly, everything is made of chemicals. Water is a chemical, chocolate is made of chemicals, kittens are fuzzy purring balls of chemicals. If you’re worried about substances that are toxic, poisonous, or that could otherwise harm life, the natural world is full of plants and minerals that could kill with just the tiniest taste. Handle lye with care while you’re using it, but know that science is on your side. There will be no lye in your soap when it’s finished curing.

If you’re still worried, I encourage you to try your hand with melt-and-pour soap, and if your interest is piqued, check out my free 4-part soapmaking for beginners series and the soap making videos on my YouTube channel. I hope this piece has answered your questions and I wish you the best of luck in your soap making adventures.