Make Your Own Soap, Sodium Hydroxide (Lye)

Where to Buy Lye (Sodium & Potassium Hydroxide) in Singapore

Where to Buy Lye in Singapore

Where to Buy Lye in Singapore?

Looking for lye to make homemade soap in Singapore or where to buy lye? As any soap maker will know, lye (sodium hydroxide and potassium hydroxide) is a necessary chemical to make real soap. Whether you are using hot process or cold process soap making method, you need lye. So where can you get lye in Singapore?

The problem for soap makers in Singapore is that lye is a controlled substance in Singapore.

Sodium hydroxide and potassium hydroxide are industrial chemicals controlled as a hazardous substances under the Environmental Protection and Management Act (EPMA) and its Regulations.

No individuals are allowed to import/purchase such controlled chemicals for personal/domestic use.

Soap makers in Singapore can only get lye by renting a soap making workshop approved by NEA with a license/permit. These workshops must meet the strict safety requirements imposed by the authority and be located in an industrial building.

Then how? Does it mean that people in Singapore won’t be able to enjoy the process of soap making?

Actually, you can! By simply booking a soap making workshop with us at Singapore Soap!

By booking a soap making workshop from us, you can use our lye provided in our workshops safely! Rental for the workshop (not guided) is only at only $20 per 60 minutes block (Per Person).

Sodium hydroxide (for bar soap) are priced at only $0.08/g.

Potassium hydroxide (for liquid soap) are priced at only $0.10/g.

Other soap making ingredients and materials are available as well.

There is no need to purchase a whole list of soap making equipment and ingredients to start as a beginner!

Alternatively you can bring your own ingredients and equipment if you are already a soap maker.

Contact us @ 9483 2196 to find out more!

Are you new to soap making? No worries, understand more about lye by reading on.

Why Cannot Buy Lye in Singapore?

Many new Singaporean soap makers face this problem when starting out to learn about soap making. No matter, cold-process or hot-process soap making, you will need lye and face difficulty to buy lye in Singapore.

Unlike some countries where pure lye can be bought easily, it is controlled in Singapore because of safety and protection for the environment.

Concentrated lye solution can cause bodily damage if you are unfamiliar with the usage and you should always wearing gloves, eye protection, and an apron—especially if you are new to soap making.

Without proper protective equipment and knowledge of usage, you could harm yourself or someone beside you.

What is Lye?

Soap is technically a salt product that is made by combining an alkali with fats or fatty acids. The alkali is the lye. The fats (or fatty acids) are the oils.

The type of soap you make, bar versus liquid, is determined by the choice of the lye you use for your salt, sodium hydroxide (NaOH), or potassium hydroxide (KOH).

Lye in the form of both sodium hydroxide and potassium hydroxide is used in making soap.

While both potassium hydroxide and sodium hydroxide are strong alkali bases, the amount of KOH (potassium hydroxide) required to neutralize x grams of oil is different from the amount of NaOH (sodium hydroxide). As such, the amount of NaOH and KOH amount used per gram of oil (e.g. coconut oil) is different. soap makers need to refer to the SAP chart for the different.

Difference between Sodium Hydroxide and Potassium Hydroxide

Lye are essentially strong alkali bases (pH 13 to 14) which is highly soluble in water producing a concentrated alkali solutions. Soap makers uses lye for mixing with oil and butter to create soap. This chemical reaction process is called saponification.

pH Table

The first step of soap making involves the dissolution (or dissolve) lye (sodium or potassium hydroxide) in water.

This chemical reaction process can cause a high exothermic reaction where large amount of heat is liberated during the process and could pose a threat to safety e.g. through the possibility of splashing.

The resultant solution (of water and lye) will be used to saponify base carrier oils or butters to make soap. Lye solution is colorless, odorless and feels slippery when it comes in direct contact with your skin. This happens because oils on your skin such as sebum are converted to soap.

Note of precaution: ALWAYS pour lye slowly in small moderate amount into water, NEVER the other way round. Adding water to lye can cause a volcano-like reaction.

What is Sodium Hydroxide?

Sodium Hydroxide (NaOH), also known as lye, is an essential ingredient in the soap making process. When sodium hydroxide beads or flakes are mixed with a liquid, a lye solution is created. This solution, when mixed with fats and oils, will cause a chemical reaction called saponification. The result of saponification is beautiful handmade soap.

In soap making, sodium hydroxide is used to make bar soap. It is also the most commonly used lye when you are learning about cold process soap making.

Sodium hydroxide is also known as caustic soda. Chemically, it is an inorganic compound with a formula NaOH (the compound consisting of sodium cations Na+ and hydroxide anions OH−) [1]

Pure sodium hydroxide is highly soluble in water but has a lower solubility in ethanol and methanol.

Sodium hydroxide can be made (with chlorine and hydrogen) using the chloralkali process. If you are interested to learn more, check this youtube video out.

A solution of sodium chloride is electrolyzed and sodium hydroxide is made around the cathode, where water is reduced to hydrogen gas and hydroxide ion. The hydrogen is released and the hydroxide bonds with the sodium to make sodium hydroxide. [2].

What is Potassium Hydroxide?

Many people only make solid bar soap, and it’s easy for those soap makers to get the impression that the word “lye” means only sodium hydroxide (NaOH).

Potassium Hydroxide is a type of lye specifically used to make liquid soap. It is the main akali used in the production of liquid soap and, other than sodium hydroxide. A common example of liquid soap or soft soap is the castile liquid soap e.g. Dr Bronner.

Commonly used to make liquid soap, shave soap, and cream soap, it is sometimes found in bar soap recipes too.

Structurally, it is an inorganic compound with the formula KOH (commonly called caustic potash). Along with sodium hydroxide (NaOH), this colorless solid is a prototypical strong base.

Also known as potash, lye or even KOH, it induces saponification of the fats and oils to create liquid soap.

Like sodium hydroxide, it is highly hygroscopic (meaning it attracts moisture), so be sure to keep it in a sealed container in a cool dry place.

If you leave it in an open container for even a day, it can attract enough moisture to throw off its weight enough to ruin a recipe and always remember, it is just as caustic and it is advised that you practice precautions when using it as well.

Potassium Hydroxide Lye Flakes KOH

Traditionally, soap makers makes lye using wood ash. Wood ash is the powdery residue remaining after the combustion of wood, such as burning wood in a fireplace or bonfire. The ash should come from hardwoods as soft woods are too resinous to mix with fat and water (preferably rainwater).

To make wood ash lye, ashes of wood or other plant material are soaked in water to dissolve water-soluble alkaline compounds in the ash. The liquid that is collected from this process is wood ash lye or “potash” solution.

If the water in this liquid is evaporated, the solid crystals of impure potash can be heated and further purified to “pearl ash”.

The problem with making lye from wood ash, although it is a simple process, the end result can be that your lye water is either too strong, or too weak. Either way, it could spoil your batch of homemade soap.

Check out this youtube video if you are interested to learn how to make your own woodash from scratch.

Can I Make Soap Without Lye?

There are many ways to make soap, but more commonly used are hot process, cold process and using melt and pour soap bases.

If you are planning to make your own handmade soap from scratch, either by hot or cold process method, you will need lye. Period. But its no secret by now that you will not be able to purchase lye as an individual in Singapore. No point searching for where to buy lye online as you will not be allowed to import.

It is impossible to make real soap without lye because there are no substitution for the purpose of saponification of oil. You need lye to saponify base oil and butter in order for it to turn to soap.

There is a way for Singaporean soap makers to make soap without using lye, that is thru the use of melt and pour soap bases. Soap bases are essentially made through hot process with added humectant (e.g. glycerin and propylene glycol) for moisturizing and melt-ability.

With melt and pour soap base (also known as glycerin soap base), you can easily make soap in the comfort of your home without the need to source for lye.

If you are looking for a better soap base, consider detergent free melt and pour soap bases. At Singapore Soap, we are also a manufacturer of detergent free melt and pour soap bases. Our soap bases are made from natural coconut oil for cleansing with no synthetic surfactants.

There are some of melt and pour soap bases with added detergents e.g. SLES or SLS as a foaming agent. These soap mimicking chemicals are generally used to reduce cost or for foaming.

Look at the soap base ingredients for words like e.g. Sodium lauryl ether sulfate, sodium laureth sulfate, phthalates and many more. These are potential skin irritant and could complicate skin conditions.

Just check the ingredients listed on these bases and do a google search for each of the items. Sadly, there are very few true soaps on the market. Most store bought body cleansers, both liquid and solid, are actually synthetic detergent products.

Detergent cleansers are popular because the chemicals used are cheap, 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 or genuine soap according to the regulatory definition of the word.

“Melt and Pour Soap” is the name given to soap bases that have already undergone the usual soap-making process – in which particular oils are combined with an alkaline solution to create a reaction known as saponification.

Melt and Pour soaps are ready to use; simply melt the base, then pour into a mold, and allow it to set. In other words, Melt and Pour soap is pre-saponified soap that can be used with or without further chemical processing or customization.

Like “true” soap, Melt and Pour soap has been made through the saponification process with a combination of ingredients that are also used in traditional soaps – which might be considered to be more “true” – and these include natural oils as well as lye, thus Melt and Pour soap does not need to have lye added to it, as doing so would be an unnecessary extra step that would cause the soap base to potentially burn the skin.

Additional Glycerin is added to the Melt and Pour soaps, offering more soothing and hydrating properties to the skin. It also helps produce clear soaps that can be easily colored and shaped and that are gentle on the skin, making Melt and Pour soap ideal for use on sensitive skin types.

At Singapore Soap, we are also a leading manufacturer and wholesaler of melt and pour soap base in Singapore. You can buy them here.

Where To Buy Lye (Sodium & Potassium Hydroxide)?

Stop wondering where to buy lye in Singapore and start making soap by renting our soap making workshop approved by NEA today!

At Singapore Soap, our workshop is approved by the authority for soap making and you can simply purchase lye (sodium hydroxide & potassium hydroxide) to make your hot or cold processed soap and bring them home.

Now who says Singaporean soap makers can’t make real genuine soap in Singapore?

Start making your own soap, without the headache of how to get lye in Singapore and the need to purchase a whole list of soap making equipment and ingredients to start!

So stop worrying about where to buy lye in Singapore and book a room for your soap making session.

Simply book our soap making workshop, click here to find out more

Rental rates are at $20 per 60 minute block (Per Person) only with no minimum blocks per rental (comes with all the basic equipment to make soap) and come on site to make your soap!

Additional soap making materials like lye, oils, butters, colorants and molds can all be purchased at site!

Frequently asked questions

Can I find lye in stores?

No. Lye is a controlled chemical under EPMA in Singapore. Forget about searching for where to buy lye in Singapore. You will not be able to find or buy lye in any stores in Singapore. Looking for drain cleaners in Singapore? Those in Singapore are not 100% pure lye.

Is caustic soda the same as lye?

Yes. Caustic soda, also known as sodium hydroxide or NaOH, is lye used for making bar soap. Lye for making liquid soap e.g. castile soap, is potassium hydroxide, also known as potash or KOH. Both sodium and potassium hydroxide are lye.

Is there a substitute for lye?

No. You need lye for the saponification process in order to make real soap. Else, you would need synthetic surfactants e.g. SLES, SLS to mimic real soap in terms of the sub, foaming and cleansing.

Can you make soap from scratch without lye?

No. You need lye for the saponification process in order to make soap from scratch. Alternatively, you can consider making soap without the need to handle lye by using melt and pour soap bases. Melt and pour soap bases, also known as glycerin soap or soap base, are ready made soap that can be melted down into a liquid and pour into mold for hardening. Once it harden, the soap is ready to use.

Do all soaps have lye in them?

Real soap are made with lye (sodium hydroxide for bar soap and potassium hydroxide for liquid soap). Any skin or hair cleansing product that is not made with sodium or potassium hydroxide is a detergent. Real soap are made with lye but there is no lye left in the finished product after saponification. During saponification, the chemical reaction between lye and other ingredients form soap.

Does Castile Soap have lye inside?

Castile soap are commonly referred to as liquid soap, although there are also castile soap bar. Both are made with lye but there is no lye left in the finished product after saponification. During saponification, the chemical reaction between lye and other ingredients form soap.

What is the pH of lye?

Lye are strong bases or alkaline. They have a pH of 13 to 14.

Is Lye Legal in Singapore?

Lye is a controlled chemical in Singapore under the EPMA and can only be used in an approved premise like our soap making workshop. It is illegal to use lye to make soap at home.


[1] Sodium Hydroxide:


[3] The Truth About Lye and Soap

[4] Is there lye in your soap? Won’t it harm my skin?

[5] Can you make soap without lye (sodium hydroxide)?

[6] Making soap without lye: How to avoid the dangers of lye?

[7] How to make your own sodium hydroxide (lye)?

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Singapore Soap is a wholesale supplier for soap making supplies, candle making supplies and manufacturer of natural castile soap, melt and pour soap bases, liquid soap bases and hand sanitizer in Singapore. We carefully source and select quality and cost effective ingredients to ensure our customers receives only the best quality products at the most economical wholesale price. You can also learn to make your own DIY soap with our soap making lessons in Singapore. We conduct soap making classes for soap makers to learn how to make soap. Join our easy-to-learn classes and learn the benefits of why handmade soap are better and healthier for you.

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