All soap is created by combining fats/oils with an alkali (i.e./ lye). BUT you can use something called melt and pour soap base, which no longer contains lye, to make soap products.
Also known as “glycerin soap,” you simply have to melt the soap block and then pour it into a mold in order to “make” a bar. You can do a lot more however by adding color, fragrance, essential oil, and exfoliates.
Combining the MP soap bases, choosing the mold, adding the color, fragrance and add-ins, then forming the bar if how you can make a melt and pour soap product without having to make the soap base itself.
Can I make soap products without using lye?
Yes – absolutely! Many soap makers use something called “melt and pour” soap bases, or glycerin soap, to create soap bars, liquid soaps, and shampoos. It works just like the name implies. You melt pre-made soap from a block (base) and then pour it into a mold to get the desired bar shape.
To make it your own, you can add color, scent, exfoliates and much more. Some people even use clear melt and pour base and embed small plastic toys in eth bars of soap to encourage children to use the soap.
Why is lye needed to make soap?
This will sound strange, but soap is a salt (specifically a fatty acid salt). It is created when fats and oils (aka/ triglycerides) are combined with an alkali such as sodium or potassium hydroxide (aka/ lye) to undergo a natural bio-chemical process called “saponification,” which is just the technical way of saying “to become soap.”
Lye is an alkali, also known as “caustic soda,” is a liquid soluble compound. This means it breaks down in certain liquids, such as water. This is important because caustic soda alone will not turn fats into soap. It is the “alkali solution,” or lye water, that interacts with the fats and oils to cause saponification.
Is lye dangerous?
Working with alkalis can be dangerous – especially if you don’t know how to do it properly. Although lye is a “base,” once added to water the solution becomes acidic – as in super hot and expelling noxious gases.
Lye should be handled with caution and respect. The instant the alkali is added to water it begins to dissolve and creates a what is known as an exothermic reaction. This means the “solution” undergoes a dramatic temperature increase.
When using room temperature water, the alkali solution can reach – and potentially exceed, 200 degrees Fahrenheit (93 degrees Celsius). Nearly boiling, this will scald, and cause severe burns to the skin.
The solution also results in fumes, which can sting the eyes and should never be inhaled.
Lye Safety
I’ll create a separate post on lye safety, but for now here are few general rules to follow when handling alkalis such as caustic soda:
- Store lye in a clearly labeled sealed container, in a cool and dry place, NOT accessible by children or pets.
- Use safety goggles when mixing it with liquid (good goggles with full protection from splashes).
- Protect yourself from burns by wearing good safety equipment and not having exposed skin when mixing your alkali solution. This can include, but is not limited to, long sleeves, full length pants, protective gloves, etc.
- Always add the lye to the water – NEVER the other way around. Also be sure to add it slowly and gently stir it in. This is so the liquid does not have to dissolve a massive amount all at once.
- Only mix the alkali solution in a well-ventilated area as the fumes can be dangerous if inhaled.
- Never work with lye in area where children and animals can potentially come into contact with it.
- Do not use aluminum bowls, cups, or utensils. It reacts poorly with the lye solution.
- Only use containers that can safely handle the alkali solution (temperature, etc.)
These are just a few basic tips.
Does soap contain lye?
No. Once the saponification process is complete, the caustic soda has been used up. It is gone. The reason lye is listed as an ingredient on most bars of soap is because the soaper (aka/ soap maker) is telling you what went into producing the soap.
Some soapers will simply not list any of the ingredients used purely for making the soap and simply state “soap” as the product output. They still need to list any essential oils, clays, colorant, scents, etc. However, as long as the product is true “soap,” they can summarize under that umbrella.
What is “true soap”?
Most people use the term “soap” generically to describe any solid or liquid cleaning product – but the description is often inaccurate. For a cleaning product to be genuine “soap” it has to meet certain criteria as defined by the governing body where the product is manufactured and/or sold.
Here is the link for the Unites States FDA.gov page that provides this information: https://www.fda.gov/cosmetics/cosmetic-products/frequently-asked-questions-soap
It’s very confusing because manufacturers can often still get away with calling a product “soap” even if it doesn’t match true definition. Here’s a quote from the aforementioned FDA.gov webpage referenced above.
“Today there are very few true soaps on the market. Most body cleansers, both liquid and solid, are actually synthetic detergent products. Detergent cleansers are popular because they make suds easily in water and don’t form gummy deposits. Some of these detergent products are actually marketed as “soap” but are not true soap according to the regulatory definition of the word.”
United States Food & Drug Administration – Excerpt from FDA.gov
What is the difference between “soap” and detergent?
As we saw a few minutes ago, true soap is derived from the organic bio-chemical reaction of saponification. Detergent, on the other hand, is made through artificially forced chemical reactions that produce a synthetic cleaning agent.
In general, detergent is often used because it is cheap and produces large bubbles that most people assume means great cleaning power. It does not, by the way.
Natural deep-cleaning power comes from the glycerin that is a natural output of the saponification process. The bubbles might be smaller and lather creamier, but the cleaning power is tremendous.
So why add detergent to the glycerin in those mass-produced cleansing products? The truth is many large cleaning product manufacturers sell off the valuable natural glycerin and replace it with chemical detergent. This is why you might see a product called a “bath and beauty bar,” or “moisturizing cleansing bar,” etc. It’s how they can sell detergent based “beauty and cleaning” bars, without calling them soap.
Even though it is still legal to use the word “soap” on these labels, in the United States and some other nations, smart marketers want to avoid any future issues with the FDA.
Rebranding a product from “laundry soap” to “laundry detergent” would cost millions of dollars and make people question what changed in the product. Most manufacturers were smart enough to get ahead of the curve by branding with the term “detergent,” which is now second-nature to most folks – at least in the United States, where I live.
What is this “no lye” soap I keep hearing about?
The term “no lye soap” can mean a couple different things so let’s get a clear understanding of what we mean.
Most commonly “no lye” refers to the melt and pour (aka/ glycerin soap) that we talked about a few minutes ago. The soap base was made with lye, but that got used up. The person now making the bar soap does not need to handle any alkali solution, powder or crystals.
The other meaning behind “no lye soap” is that once something is technically considered soap – the lye is already gone. It got used up completely in the saponification process.
You can think of lye as the fuel source that “cooks” the oils and fats into soap. That is NOT a good technical description. It is just intended to help explain the process more clearly. Not coincidentally, the most common form of lye comes from reduced hardwood charcoal ashes. In fact, another common name is “potash” (pot-ash).
Different types of lye – and Common names
There are two main types of lye used in soap making: sodium hydroxide and potassium hydroxide.
- Sodium Hydroxide (NaOH) is used for making hard soap, such as for bars. This type of lye is also known by common names including Caustic soda, Sodium hydrate, and Soda lye.
- Potassium Hydroxide (KOH) is used for making soft soaps, such as liquid or gel. Common names for this type of lye include Caustic potash, Potassium hydrate, and Potassium lye.
Sometimes both lye types are used in a single batch of soap to make a softer solid soap that required a creamier texture. This is common is shaving soaps and is a bit more of an advanced technique.
A final note on working with lye – or not
Working with lye for the first time can be scary – but then again can guiding a 3,000lb missile at 70mph (aka/driving a car.) That said, I use the same strategy when doing either. Respect the process and the rules and always think safety first.
If you don’t want to use lye, but still want to make soap, no problem. Use melt and pour soap bases to create your very own masterpieces.
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There’s a quick post on this site that gets a lot of great feedback from those who want to make soap – but NOT work with lye. It’s called Is Melt and Pour Soap Cheating? Check it out if you have 5 minutes. You can build a profitable business specializing in melt and pour. This article will get you started.
Happy soaping!