Like all soap, melt and pour soap base (a.k.a. Glycerin soap) is created by using lye in the soap making process. But the final product does not contain lye.
Many larger producers of melt and pour base mix in additional glycerin to make the final product easier to work with. Believe it or not, the added glycerin often comes from large soap companies that sell it off and replace it with much cheaper detergents in their own products.
This is one of the reasons melt and pour is also often called “glycerin soap”. It has added glycerin in order to provide the eventual soaper with an easier to work with batch.
I should also mention another, less common nickname; “no lye” soap.
Why call melt and pour soap “no lye”?
Again, all soap is made by using lye, however, should not contain any lye in the final product. The reason melt and pour soap base (MP) is sometimes referred to as “no lye” is because the person working with the MP does not need to handle lye, which can be dangerous – especially if not done properly.
The lye that was used to make the MP base was used up in something called the saponification process. This is where the lye combines with fats and oils to make soap. It’s an organic chemical reaction and happens in nature under specific conditions.
The legend of lye and soap…
Legend has it that soap was accidentally invented by ancient Romans as a result of religious rituals. Warning to animal lovers – skip this part…
The story goes that during religious sacrifices animal remains were often burned on an altar. When the fire was made from hardwood, the ashes burned to lye. When combined with mineral-free water (such as rain). it would become a lye solution. The lye solution would mix with the rendered animal fats and go through the saponification process, naturally producing soap.
It might just be a clever way to explain where soap came from. Even the name of the mountain where the rituals supposedly took place is spot-on; Mount Sapo (where we get “Saponification”).
It is a fun story and does wrap up the origins of soap in a nice neat package.
- Lye is made from ashes (the white ashes) of hardwood trees with enough potassium, such as ash and hickory.
- Rainwater is as close to mineral-free as you can get without using a distillery.
- And finally, having animal fat sit in a pile of water-soaked lye to saponify is not difficult to imagine.
Is all “no lye” melt and pour soap base the same?
Not at all. You can get MP that is all natural, organic, and even those with added detergent for bigger bubbles. There are also newer types called LCP. This means “like cold process”. There are also “suspension” types that are ideal for solid additives.
There is far too much to cover in this post. I’ll post another dedicated just to the subject of discussing different types of glycerin soap. For now, however, let’s get back to the subject of lye.
Should I avoid lye?
There are plenty of reasons people either do not wish to work with lye – or simply are unable. We will get into those in a moment. But before we get into the dangers of working with lye, let’s get a fuller picture. I don’t want to instill any unnecessary fear. I respect lye, but I don’t fear it and I use it nearly every single week.
One of my favorite soap bloggers, Mommypotamus, summarized it best when she said:
“Lye is definitely something we want to be careful around, but it’s not something we want to be scared of. Our great grandmothers made lye by burning hardwood ashes.”
Heather Dessinger of Mommypotamus.com
In my experience, Heather is spot-on. In fact, my great grandparents made their own soap and lye, during the great depression. It worked out so well, they continued making it rather than buying it. By the way, Mommypotamus has a great video tutorial on making hot process coconut oil soap below. The lye discussion starts at 5 minutes 12 seconds in – but the entire video is well worth watching.
Reasons to respect lye (but NOT fear it)
Lye can burn on contact: Lye is a base that will burn the moment in comes in contact with moisture. It is also excellent at finding every bit of moisture around it and drinking it in. Your skin, for example, is loaded with moisture. This means if you get even a single crystal of lye on your skin, it can burn you almost instantly.
For this reason, it’s recommended that you wear appropriate gear. THis should include, but not necessarily be limited to:
- Eye and face protection
- Long sleeves
- Waterproof & chemical proof protective gloves that do not have wide openings that lye crystals can get into
- Long pants or a full protective apron
- Any scalp protection such as an appropriately protective hat.
This might sound like overdoing it. However, once you’ve had a good lye burn or two, you learn to respect it.
Full Disclosure: I do not take all of these precautions myself. I always make sure my eyes are well protected. I also work in a well-ventilated area free from children and animals at the bare minimum. However, I am not as cautious as I should be some of the time. Unfortunately I have accumulated a few lye burns to prove it 😉
Keep in Mind…
Following are a few important facts about working with lye.
Lye contact can lead to eye damage: I won’t even look at lye without eye protection. No, I’m not joking. I have no desire to have my corneas scarred from getting a lye crystal or lye water in there.
Even the fumes can damage your eyes if you’re not careful. I handle this by wearing actual protective lab goggles – NOT just safety glasses. I use goggles that fit my face around my eyes and offer protection from upward and sideways splashes, should they occur.
Ly water produces noxious gases: Once lye combines with liquid it creates noxious gases. These can overpower anyone in the immediate area – especially in an enclosed area that is not well ventilated. This is very big deal and needs to be taken seriously.
Whenever possible I make my lye solution outside. No matter what, I am always far from any animals that might get curious. Cat and dog parents, you know what I mean.
If I’m not able to get outside to mix the lye and water, I try to do it in front of an open window. Now that I have a shop, I use a vent hood that pulls it out and dissipates it outside after it has been scrubbed. But that’s a recent addition and doing it outside, or in front of an open window works just as well.
MP Success Story
A close friend owns a soap business that does strictly melt and pour because she has respiratory issues. She cannot risk exposure to any noxious gasses. For her, Glycerin soap is a miracle cure for being able to run a successful soap business.
Lye water can scald: Okay, we already said that lye burns. But I was talking about the lye crystals or powder coming in contact with the moisture of your skin. Once lye has been added to liquid at room temperature, such as water, it reaches a temperature of about 200 degrees Fahrenheit almost instantly.
Keeping in mind that the boiling point of water is 212 degrees Fahrenheit, I’m sure you can imagine how much getting even a drop of lye water on your skin would hurt.
The lye water will cool down. You can also keep the temperatures from getting too high by adding the lye to ice water or even directly over ice cubes in the water. Just be aware of the potential heat you are working with.
To Lye or Not to Lye
We started by answering a simple question: “Does melt and pour soap contain lye?” The answer, of course, is No – the lye was used up during the saponification process just like it is in all soap.
Just as importantly, we looked at why someone might ask the question in the first place. Lye has a reputation for scaring people to the point they have no desire to work with it. Now that you have a better understanding of what lye is – and is not – hopefully, you are in a better place to decide which route you’d like to go. I personally use both and it has worked out very well for me.
>>> The Inside Edge
We have a post detailing how you can save 40% with the right MP supplier. Check it out if you want to use melt and pour and save time and money: Finding the Best MP Supplier.
The FDA has great info on lye
If you would like more – and more official – information on lye, you can visit the US Food and Drug Administration’s page dedicated to lye.
Happy soaping!