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Lets Talk About Soap

Lets Talk About Soap

At least once every day most of us use a cake (bar) of purchased soap. Some we like, some are okay and some we just don’t buy again.

Like all products you need to read the ingredients and understand what you are putting on your skin every day. So lets go on a journey to understand one of the most used products we cover ourselves in.

What is soap made of?

Soaps are made from fats and oils that react with lye (sodium hydroxide). Solid fats like coconut oil, palm oil, tallow (rendered beef fat), or lard (rendered pork fat), are used to form bars of soap that stay hard and resist dissolving in the water left in the soap dish.

Soap making is essentially the chemical reaction between oils, which are acids, and lye, which is a base. Together they will form a completely new material which will be gentle and nearly neutral in PH.

You use water in soap making to activate the lye and disperse it through the oils. Most of this water evaporates out of your bars during the curing process

Oils such as olive oil, soybean oil, or canola oil make softer soaps. Castile soap is any soap that is made primarily of olive oil, and is known for being mild and soft.

As warm liquid fats react with lye and begin to saponify, they start to thicken like pudding. At this point dyes and perfumes are often added. The hardening liquid is then poured into molds, where it continues to react, generating heat. After a day, the bars can be cut and wrapped, but the saponification process continues for a few weeks, until all of the lye has reacted with the oils.

Soaps are often superfatted, so after all of the lye has reacted with the fats, there are still fats left over. This is important for two reasons. First, the resulting soap is easier to cut, and feels smoother on the skin. Second, the extra fats make sure that all of the lye reacts, so no lye is left to irritate the skin, and the resulting soap is not too alkaline.

The chemical makeup of each different oil has an effect on the finished bar of soap. For example, olive oil makes a very hard bar of soap, with bubbles that are small and slick. Coconut oil, on the other hand, makes big, fluffy bubbles and a hard bar of soap, but it can be drying to the skin.

The saponification process results in about 75% soap, and 25% glycerine. In homemade soaps, the glycerine is left in, as it acts as an emollient (skin softener) and adds a nice feel to the soap. In commercial soaps, the glycerine is often removed and sold separately, sometimes showing up in skin moisturizers that remedy the damage done by drying soaps.

Handcrafted soapmakers have the advantage of being able to formulate soaps using all types of basic and specialty oils in order to make their unique "perfect bar." While you are very likely to find coconut or palm kernel, olive, soy or palm oils in many soaps, you will also see oils such as castor, apricot, avocado, almond, jojoba, hemp or other nut or seed oils, or butters such as cocoa, mango or shea butter.

Many soapmakers are also becoming more globally aware and are choosing their ingredients and oils not only for the quality they bring to the soap, but for their sustainability and fair trade.

You should try and avoid soaps that contain palm oil. This is not necessarily bad but it is so difficult to evaluate whether the palm oil is harvested in a sustainable manner.


It is the reaction between the lye and the oils that produces soap. Once that reaction (called saponification) is complete, all of the lye is converted into soap; there is no lye remaining in the finished soap bar.

There are two types of lye used by soapmakers - sodium hydroxide and potassium hydroxide. Sodium hydroxide is used to make solid soap; potassium hydroxide is used to make liquid soaps. A combination of the two is used to make cream soaps.


Water is used to create the lye solution that is mixed into the oils. The amount of water is dependent on the specific soap recipe, but it must be enough to allow the lye and oil molecules to get together and make soap, but not so much as to result in a soft bar of soap. The majority of the water evaporates out of the soap as it cures and ages.


Although some handcrafted soaps are left unscented, most are scented using either plant-based essential oils or fragrance oils, depending on the preferences of the soapmaker and consumer.


Essential oils come from plants and are generally considered "natural". There are several methods for extracting the essential oils, but even so the range of possible scents is limited. Perfumers, and soapmakers who have experience blending essential oils, can produce some amazing scents with just essential oils. Essential oils are often expensive making it unrealistic to use them in true soaps.


Fragrance oils are synthesized from aromatic chemical compounds which are then blended to produce the scents we know and recognize. Some fragrance oils blends may include essential oils or "nature identical compounds" (compounds which are produced in a laboratory but have the same molecular structure as those found in nature).

Most food-like fragrances (i.e. butter, coffee, chocolate) or fruity scents (i.e. apple, blackberry, cucumber, mango) are synthesized fragrance oils. Soap scented as real florals, such as jasmine, lilac, or rose are usually made with fragrance oils as essential oils from these flowers are either impossible or extremely expensive to produce.


Dyes are often used to change the colour of soap. In addition to colour additives, some specialty ingredients may cause the color of the soap to change. For example, adding french green clay to a soap will cause it to have a green color, cinnamon will turn the soap brown and paprika will turn it orange.


True soaps, made from oil, lye and water, don't generally require preservatives. You will rarely find preservatives added to handcrafted soap. Some liquid soaps, which have a high proportion of water may require preservatives.

Preservatives are only used in ‘wet’ products since water creates a habitat where bacteria can grow. Soap does not require preservatives since the water that you use in the recipe will evaporate out.

If Super-fatting is used in the soap making, and it generally is, then an antioxidant will be used to help free-floating oils stay stable and not go rancid.


You can use any oil or fat to make soap. Most soap recipes include 3-6 oils but some have a lot more, or less. Soaps made from a single oil, such as castile (olive oil) soap are uncommon because very few single oils make a good soap. Different oils give different properties to soap including hardness, lather, creaminess, and conditioning.

Most soap recipes are also super-fatted. This means adding extra oils at the very end of the soap making process that will be free-floating in your bars. These extra oils don’t combine with lye and makes the difference between a bar of soap that’s cleansing and a bar of soap that’s cleansing and moisturizing.

Common oils used in soap making

  • Beeswax – Vegetarian but not Vegan, this wax will add hardness to your soap and a beautiful scent. Use only small amounts of beeswax in your recipes since it stops lathering at larger quantities.
  • Cocoa Butter – provides gorgeous moisture and skin protection and also helps to harden your soap. Use in smaller percentages as a ‘superfatting’ oil.
  • Coconut oil – creates a hard bar with loads of fluffy lather and cleansing power.
  • Olive oil – soap made with olive oil is sensitive, conditioning, and great for all skin types.
  • Palm oil – a great oil for soap making but one that is very controversial. Palm plantations in south-east Asia have led to devastating deforestation and loss of habitat for animals such as Orangutans. If you choose to use Palm oil please consider using oil that’s been certified as sustainable and try to learn more about where exactly its being grown and by whom.
  • Soybean oil – helps create a conditioning bar with a stable lather
  • Shea Butter – an interesting oil since it has more difficulty turning into soap than other oils and will often stay in your soap as moisturizing butter rather than soap. Use in smaller percentages as a ‘superfatting’ oil.
  • Sweet Almond oil – used for its light feeling and ability to moisturize and condition the skin. Use in smaller percentages as a ‘super-fatting’ oil.


Preservatives are only used in ‘wet’ products since water creates a habitat where bacteria can grow. Soap does not require preservatives since the water that you use in the recipe will evaporate out.

If Super-fatting is used in the soap (which is common) then there is a need for an antioxidant to help free-floating oils stay stable and not go rancid. There are two main antioxidants that soap makers use in very small quantities at the very end of the soap making process.

  • Grapefruit Seed Extract (GSE) – Grapefruit Seed Extract extracted from the seeds and pulp of grapefruit this thick and clear liquid doesn’t add a scent to your soap and is very effective at keeping other oils from spoiling.
  • Rosemary Oleoresin Extract (ROE) – Rosemary Oleoresin extracted from Rosemary leaves and quite a thick and strong smelling herbal liquid.

Soap Fragrance

Some soap is made so the scent speaks for itself:  simple, clean, handmade soap. Most soaps however use oils in their recipe like sesame or beeswax since they will impart their own unique and natural fragrances. Some unscented soap is fragranced using the natural aroma of oatmeal. It’s proven popular with those with extremely sensitive skin.

However, the most common way to scent soap is with either essential oils or cosmetic grade fragrance oils.

Essential oils vs Fragrance oils

Essential oils will provide a natural scent. They’re concentrated plant and flower extracts and come in a fairly extensive range. The downside of using essential oils is their expense and propensity for fading with time. It’s especially problematic for citrus essential oils such as lemon and orange.

Fragrance oils are commercially produced perfumes for the toiletry industry. They’re relatively inexpensive, have scent that lasts ages, and have a much more varied range to choose from. For example if you like baby powder scented soap or a shampoo that smells like coconut then you’ll be buying soap that uses fragrance oils.

Most fragrance oils are trademarked and patent protected. That means that you’ll never truly know all the ingredients used to make them. In many cases fragrance oils are made of petrochemicals and allergens that cause people to sneeze or have skin reactions

A soap that’s subtly scented and leaves your skin smelling lovely can be obtained by using small amounts of essential oils.

Scent Fixer

The scent of essential oils can fade over time but there are ways to ‘fix’ the scent so that they’ll last longer. Sometimes another essential oil can help the others to stick and at other times it’s best to use another additive that works to absorb the essential oils into it.

Below are some common fixers you may come across:

  • Arrowroot 
  • Benzoin 
  • Cornstarch 
  • Oatmeal 
  • Orris Root Powder 
  • Essential oils

Soap Colours

In natural soap there are several options for colouring the soap which will include speciality powders, flowers and plants thar are naturally grown.

Other options are oils that will impart a natural hue to the soap. These could include clays, plant extracts, or ingredients that will caramelise and give a warm color to the finished product.

Oil Selection – some of your oils, such as olive oil, will impart a more yellow or creamy colour. White and/or light colored oils will create white soap.

Clays – though limited in palette, cosmetic clays can add beautiful natural colour to your soap. Clays can also create bars that lightly exfoliate and detox the skin.

Minerals & Micas – Mineral and Mica powders are available in a wide range of colours. However, not everyone considers them natural. They’re more accurately labelled as ‘Nature identical’ rather than ‘Natural’. Minerals and micas are found in nature but are often tainted with unsafe heavy metals and are unsafe to use. That’s why the ones available for mineral make-up and soap making are reproduced in a controlled environment.

Sugars – milk, sugar, and honey will caramelise.

Herbs, Flowers, & Roots – Nature creates all types of wonderful colours useful in soap making calendula petals for golden orange, alkanet root for purples, Madder root for pink and Spinach to give a brilliant green hue.


There is no doubt that handmade/organics soap will provide a much richer experience and will provide more care for your skin than factory soaps. It is all about the ingredients so you need to spend a little be of effort on product that has a large impact on a large part of you.

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