• Erin

Is there lye in natural soap? Will it hurt my skin?

I have had a few questions and comments over the years about lye and how folk have found soap made without lye. I’d love to share with you some information about lye and its purpose in saponification (soap making) and what it means for us!

What is lye anyway? Lye is an alkali, a soluble salt of an alkali metal like sodium or potassium. The alkalis used in soapmaking used to be obtained from the ashes of plants!

The question asked many times is: Do you use lye to make soap? Yup, we sure do!

Why? Because without the alkali, you cannot saponify the oils and make soap. All real soap is made with lye. Skin or hair cleansing products made without lye is not soap, it is detergent.

What I belive folk really want to know is: IS THERE LYE SPARROW SOAP BARS?

No. There is absolutely no lye in your Sparrow Soap bar.

But wait – you use lye to make the soap, but there isn’t any in your soap? That doesn’t make sense!

I know, but let me explain… You may have seen me talk about saponification before at market days or on social medias, so you will know that when the chemical reaction of making soap, called saponification is complete, the lye and oil molecules have combined and chemically changed into soap and glycerin. If the soap is made carefully and correctly, the lye is used up in the saponification process to turn oil or fats into soap. There is no lye present in the finished bars of soap. While all real soap must be made with lye, no lye remains in our finished soaps after saponification.

Lye isn’t listed on the ingredients though! If it is real soap or contains real soap, it is made with lye – there is absolutely no way around it – consider it a law of nature!

Commercial "soap" bars and handmade soap bars are also made with lye even though the words "sodium hydroxide" or "lye" may not appear on the labels. Some ingredients you may find are:

• saponified oils: oils and butters are mixed with sodium hydroxide and a liquid (usually water)

• sodium tallowate: the generic name for the mixture of beef fat (tallow) with sodium hydroxide (lye).

• sodium cocoate: the generic name for the mixture of coconut oil with sodium hydroxide (lye).

• sodium palm kernelate: the generic name for the mixture of palm kernel oil with sodium hydroxide (lye).

• sodium palmate: the generic name for the mixture of palm oil with sodium hydroxide (lye).

• sodium olivate: the generic name for the mixture of olive oil with sodium hydroxide (lye).

I have had so many folk come to speak to me about how they cannot use soaps and they can only use Dove or other body washes because of the lye. Be careful of what large manufacturers advertise about their soaps (what is the ¼ moisturiser anyway?) Even though the words "lye" or "sodium hydroxide / potassium hydroxide" did not appear on the ingredient label, read what the first ingredients listed can be, such as sodium tallowate or sodium palmate. Yes, these commercially mass produced soaps are also made with lye! Also, keep an eye out for other wording styles such as “potassium soaps” or “sodium soaps”. It’s the same thing and means that Potassium Hydroxide or Sodium Hydroxide lye was used to make soap from oils.

At Sparrow Soap, we like to keep things simple and avoid the technical stuff, even though many natural soap makers know that consumers are afraid of the word “lye”, we know that it is better to educate our highly valued customers, rather than to try to hide from a word that is so often taken out of context and misunderstood. You can easily find all this information on the world wide web too but I thought I’d make it easy for you to get it all in one spot! Just be careful what you read though because some of it is just downright ridiculous.

So what is Saponification? Saponification of fats and oils is the most widely used natural soapmaking process. This method involves heating fats and oils and combining them with a liquid alkali to produce soap and water, plus glycerine. In commercial soaps, the glycerine is often removed and sold separately, sometimes showing up in skin moisturizers that remedy the damage done by drying commercial soaps. Yup.

Fatty acids that make up the triglycerides present in oils. Once we select the oils and mix them with sodium hydroxide and lye, the molecules combine and the chemical reaction called saponification occurs. A totally new substance is created (soap) with no lye remaining. Note: this is why all Australian soap makers must be registered with the relevant government body and have substantial experience in these chemistry processes. Ask me about that if you’re really curious!

Superfatting One special thing to remember... all handmade soap is not created equal! It takes the careful and considered education of an experienced soap maker to produce a truly gentle and effective bar of soap. Not all oils are equal, and the quality of ingredients has a huge range here in Australia. Superfatting is one way we can ensure that all Sparrow Soap bars contain more fat in the mixutre than the lye can react with during saponification. We add extra oils and calculate the recipe precicely so that our superfatted soaps have superior moisturising and lathering qualities. One of these days I'll write another post explaining how not all handmade soaps are the same.

Chemical reactions happen all the time in many different ways. Here is another example: Sodium (Na) is a highly reactive element that explodes if it comes into contact with water and Chlorine (Cl) is a deadly poisonous gas (its green too so that must make it super deadly!) However, when they come together in a chemical reaction a totally different substance is created - table salt (NaCl). There is none of the explosive sodium or deadly poisonous chloride gas left at the end! You can see it being made here https://youtu.be/d2geiGKFveE

More interesting facts about lye...

Lye has many uses in the food industry, including but not limited to washing and chemical peeling of fruit and vegetables, preparation of olives, German pretzels and rolls. Most crazy thing I found out was that lye is used in the processing of CHOCOLATE and COCOA. Love that yummy looking caramel colour? Lye is used to produce that too, as well processing and thickening ice cream!

Well I hope I have been able to answer the queries on the use of lye in making natural soap. If you have a question you’d like to me to investigate, feel free to contact us!

Until next time, be kind to your skin.



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