Table of Contents
- What is saponifiable and unsaponifiable matter in soap?
- Why is unsaponifiable matter important?
- Which of the following fat or oil is unsaponifiable?
- Which oil has the highest saponification value?
- Which oil is best for saponification?
- Conclusion
What are unsaponified oils in soap? In soap-making, unsaponified oils refer to the portion of oils or fats that do not undergo saponification—the chemical reaction between oils and lye (sodium hydroxide or potassium hydroxide) that transforms them into soap.
Even though these oils are unsaponified, they play a crucial role in the outcome of the soap.
“Unsaponified oils” are intentionally included in a soap recipe by reducing the amount of lye in the soap or adding excess oil or superfatting,” as they call it (lye discount or superfatting are the same).
This technique aims to enhance the soap’s moisturizing properties and make it gentler on the skin.
Certain oils, such as coconut and palm oil, have a high saponification material due to their fatty acid composition.
The fatty acid composition of oils such as coconut, palm, babassu, and palm kernel oil tends to dry the skin if used in high concentrations in a soap recipe.
This necessitates combining high-saponification oils like coconut and palm oil with low-saponification oils like olive or avocado.
This combination helps to create a balanced soap that is less likely to dry out the skin and contributes to the soap’s moisturizing abilities.
In this article, I’ll explain unsaponified oils, how they impact soap, and why they are essential in crafting high-quality, skin-friendly soaps.
Let’s Start!
What is saponifiable and unsaponifiable matter in soap?
In soap production, the terms saponifiable and unsaponifiable refer to different components of the oils and fats used in soap making.
When discussing fats and oils in the context of soap making, it’s essential to understand that most fats and oils have both saponifiable and unsaponifiable components in different proportions.
However, the term “unsaponifiable” refers specifically to the portion of the fat or oil that does not undergo the chemical reaction of saponification and remains in its original form within the final soap product.
Saponifiable Matter: Saponifiable matter refers to the portion of fats or oils that can be hydrolyzed (broken down) into fatty acids when treated with an alkali (such as sodium hydroxide or potassium hydroxide).
This hydrolysis process is known as saponification. When fats or oils are mixed with an alkali, they react to form soap.
Hydrolysis is the chemical breakdown of a compound due to a reaction with water. The saponifiable matter in these substances contributes to the soap-making process.
For example, triglycerides (the main components of fats and oils) consist of three fatty acid chains attached to a glycerol molecule.
During saponification, these triglycerides break down into glycerol and salts of fatty acids (soap).
In contrast, unsaponifiable” refers specifically to the portion of the fat or oil that does not undergo the chemical reaction of saponification and remains in its original form within the final soap product.
For example, shea butter has a high amount of unsaponifiable matter because it contains steroids; steroids are unsaponifiable.
Suppose you’re using a high percentage of oils high in lauric acid, like coconut, palm kernel oil, palm oil, or babassu oil in your recipe.
Even though these oils have intense cleansing abilities, they are susceptible to drying the skin and contain high saponifiable matter because of their fatty acid properties; hence, blending oils with high saponifiable matter and those with high unsaponifiable is critical to having a balanced soap.
Why is unsaponifiable matter important?
When we create soap through a process called “saponification, fats and oils react with an alkali (such as sodium hydroxide or potassium hydroxide) to form soap.
However, some components within these fats and oils resist this transformation—they remain “insoluble in water” and do not turn into soap.
These components are known as “unsaponifiable’.
Unsaponifiables can have various beneficial properties, such as moisturizing and conditioning effects, and they affect the texture and consistency of soap.
For instance, shea butter contains non-saponifiable components that give it unique texture and emollient capabilities.
Shea butter mainly consists of saturated stearic acid and unsaturated oleic acid. However, it’s essential to strike a balance.
An excessive proportion of oils with high unsaponifiable matter in a soap recipe can lead to inferior or defective soap.
Which of the following fat or oil is unsaponifiable?
Which oil is not saponifiable? To identify unsaponifiable oils or fat, it’s not accurate to say that any fat or oil is entirely unsaponifiable.
Instead, certain fats and oils have higher percentages of unsaponifiable matter, making them particularly beneficial in soap-making.
Also, an oil should not be considered unsaponifiable because it contains unsaponifiable materials.
Those materials still exist within the oil, but they will not turn into soap when they go through alkaline hydrolysis because they have no fatty acids in their composition.
Common Oils with High Unsaponifiable Content:
- Olive Oil (Extra Virgin)
- Avocado Oil
- Shea Butter
- Jojoba Oil
- Wheat Germ Oil
- Rice Bran Oil
- Rosehip Oil
- Hemp Seed Oil
- Sesame Oil
- Argan oil
Lye reduction, or superfatting a soap, is a technique soapers use to avoid excess lye and add moisturizing properties to the soap, mainly when their recipe contains a high percentage of oils high in mystic and lauric acid.
Which oil has the highest saponification value?
Oils with a high percentage of lauric and myristic acids tend to have the highest saponification values.
For instance, coconut, palm, and palm kernel oil fall into this category, with saponification values ranging from 235 to 260 mg KOH/g of oil.
These values indicate the amount of potassium hydroxide (KOH) required to saponify 1 gram of oil.
Which oil is best for saponification?
Different oils contribute unique characteristics to the soap, such as lather, hardness, cleanliness, and conditioning.
Every oil saponifies! When lye and oil are well mixed, they undergo a chemical reaction called saponification to become soap.
However, some oils saponify faster and contain more saponification material than others—such as coconut, babassu, palm kernel oil, etc. Read more about oil properties.
Every soap recipe demands a different base oil and butter combination, so the oil combination will depend on the kind of soap you want to make.
Examples of oils that saponify fast are coconut oil, shea butter, cocoa butter, palm oil, lard (animal fat from a cow), tallow fat, lauric oil, and many more.
Furthermore, depending on the soap in question, the oils should combine hard oils, butter, and soft oils, at least for a simple soap recipe.
The hard oils are saturated fats that give your soap hardness, longevity and lather. Here, you find oils like babassu, coconut, palm oil, etc.
The soft oils are unsaturated fats; they add conditioning properties to the soap.
The section consists of oils such as olive oil, almond oil, sunflower oil, rapeseed oil, rice bran oil, and more.
In the butter section, you will find cocoa butter, shea butter, mango butter, etc. These butters also condition and harden your bar soap.
Even though it doesn’t fit into any category, Castor oil is an excellent addition to the soap recipe.
Oil Combination for Basic Soap Recipe:
As a guide, try 35% hard oils. That would be palm oil, coconut oil, lard animal fat, or tallow fat. They all have similar properties.
So just try one of them or a mixture of them. Most people will go for coconut oil because it’s relatively easy to obtain, and you can use any coconut oil you get in the shop.
So 35% of your recipe will be hard oils; 15% can be butter, so that could be cocoa butter, shea butter, mango butter, or whatever butter you like the look of.
If you wish to add fragrance to your soap, the remaining half of the oil blend can consist of soft, luxury, and essential or fragrance oils.
So, you could use 30% olive oil or rice bran oil, which has very similar properties, 10% castor oil, 5% luxury oil like grapeseed or avocado oil, and 5% E.O. or fragrance oil.
When creating soap, the choice of oils plays a crucial role. Each section in a soap calculator presents several oil options.
The type of soap you intend to make determines the ideal oil combination.
Conclusion
In soap making, both saponifiable and unsaponifiable matters play essential roles.
Saponifiable matter is crucial for the soap’s cleansing and structural properties, while unsaponifiable matter enhances the soap’s skin-care benefits.
Additionally, consider your Budget and accessibility when selecting oils. Some oils are more expensive than others.
Therefore, choosing items that are both affordable and readily available to you is essential.
