Soap making oil properties that are great for cold process soap.

Soap making is an art form that many will find to be rewarding and even therapeutic at times. To get to this state however takes some practice and much patience. The beginner will find it utterly frustrating, and the learning curve can be costly when making mistakes. As you grow you will learn that using various oils help develop different soaps and techniques, hence it’s great to know your soap making oil properties.

The soap making oil properties of basic oils for cold process soap making are good to know when designing your personal soap. These basic oils include olive oil, coconut oil, castor oil, sweet almond oil and palm oil (sourced sustainably).

Learning more about the oils or fats used in soap making will help you develop new soap recipes with various benefits all based on the oils, fats or butters used in your soap. To do this however you will need to gain and understanding of what each oil, fat or butter does in your soap.

I have compiled a list of oils, fats and butters below that states if they are considered Hard or Soft Oils, their properties and benefits in soap, how much you can or should add to your recipe and more information to consider on each of them.

Let me break things down into sections. Here is a list of Oils I will discuss

soap making oil properties

Soap making oils

  • Coconut Oil
  • Palm Oil
  • Olive Oil
  • Lard
  • Tallow (beef)

Hard or Soft Oil?

When an oil is considered hard or soft it refers to its natural state. For example, cocoa butter is considered a hard oil. A better example would be Coconut oil. Coconut oil melting point is 76 degrees. Which means in an environment cooler than 76 degrees the oil will begin to solidify, that is harden.

Olive oil or sweet almond oil on the other hand is considered a soft oil because even at cooler temperatures it remains in its liquid state. There are more soft oils than hard oils available on the market.

A third state of an oil can be brittle. Brittle oil such as cocoa butter and palm kernel oil get extremely hard that they can be broken into pieces like a frozen chocolate.

NOTE – be careful of where you source your oils from as not all oils are created equally. There are fake oils on the market that can wreak havoc with your recipe. Learn more about Unadulterated oils

soap making oil properties oil mixture

How much oil should I add to my soap recipe?

Knowing how much oil should be added to your soap recipe is mainly determined by the size of you mold. The good news is that there is a formula that works very well in determining how much total oil is needed in your recipe for a certain mold.

Oil amount calculation

Not all soap recipes are the same. The key to using a certain recipe is to ensure you have all your measurements based in percentages.

What this means is that instead of stating weight amounts such as 32oz of oil for a 40oz mold you determine the percentage of oils in the overall soap recipe.

In this case when you add your lye, water and any other type of embedded additives such as essential oil you can develop a percentage of each ingredient that will help you reproduce the final results of your soap in any mold size or shape.

There is a two-step technique to determine how much oil is needed to make soap in a particular mold

Step 1 –

Find the total volume of mold cavity. This can be done by placing the mold onto a scale, zero the scale and then add water to the mold.

The weight of the water will then have to be converted into size volume using a simple formula.

Step 2

Once you have the weight in ounces of the water that filled your mold cavity. Use this formula to determine the amount of oil needed to make soap to fill that mold.

Wo x 1.8 X .4 = Oil Needed

– Water Weight in ounces multiplied by 1.8 multiplied by 0.4 = Oil needed in ounces

How does this work? Let’s try it out.

Take a typical 40oz loaf mold. We know the volume size because we use it all the time, but for this purpose let’s see if our recipes were all correct

With your soap mold on your scale, zero out the scale and begin to pour water into your mold. All things being equal you should reach the top of the mold with a water weighing in at 45oz of water by weight.

  • 45×1.8 = 81
  • 81×0.4 = 32.4 or 32oz of oil

This number reflects the total amount of oils needed by weight to fill your soap mold. Keep in mind that some oils are lighter while some are heavier than others. Then there are butters which are the heaviest and all have different characteristics that will show up in your soap.

From this total amount of oil, you can develop your soap recipe for one or multiple oils dividing the amount of oils into a percentage base that will all add up to 100% of your 32oz of oil needed.

Oil types and behavior in cold process soap

There is a caveat to using various oil. Not all oils behave the same or have the same properties when converted to soap. For example, coconut oil when converted to soap creates a hard bar with lots of bubbles but it can be very drying to the skin.

Olive oil on the other hand makes a moderate to mid-level hard bar with low bubbles and can be moisturizing to the skin.

Knowing how much of an oil works best in a recipe is also a key component. Usually, some oils work best at a low percentage while others can be measured at higher amounts.

For example, Castor oil is best used when it is kept at or below 5% of the oils in the mixture while coconut or olive oil can be used up to 100% with a slight modification of the recipe.

The general practice for many oils lie between 5 and 50% with a few rising above the percentage.

Soap making oil properties

The properties of the oil refers to the end result of the oil in your soap. How your soap will perform with the particular oil in the recipe. This could range from the type of lather how cleansing is the bar and even the color of the finished bar without any other colorant added.

This is where you pay attention to the information as the properties will help you develop a soap to your liking by mixing oils with certain properties together with each other.

Basic Information for soap making oils

Almond Oil, sweetSoftMedium lather, mild cleansing5-12%Sweet Almond oil is a wonderful sub for some of the olive oil in a recipe.
Coconut Oil – HardAbundant lather, large fluffy bubbles, high cleansing, hard bar, white color15-50%High amounts of coconut oil can be drying, however you can always use a higher superfat to counteract the drying effect. The more un-saponified oils in your soap the more moisturizing it is.
Experiment with a 100% coconut oil soap with a 20% superfat.
Palm OilHardMild stabilizing lather, hard, long-lasting bar25-50%Palm oil is great for those that don’t want to use animal fats such as lard or
tallow. I personally do not use palm oil because of the environmental effects of producing it.
Olive Oil – SoftLow slippery lather, almost no bubbles, low cleansing25-80%The low cleansing properties of olive oil make it very mild and nourishing. Soap for sensitive skin, elder skin or baby skin should include high amounts of olive (60%). Castile soap is made with 100% olive oil. I classify this
as a soft/hard oil because it makes a very soft bar of soap initially upon unmolding but cures into a rock hard
bar. Soaps high (50%+) in olive oil need longer to cure and unmold.
LardHardMild stabilizing creamy lather, hard, white bar25-50%100% lard soap with no superfat makes great laundry
Cocoa ButterBrittleMild stabilizing lotion-like lather, hard, long-lasting bar5-15%You can experiment using cocoa butter and other butters in high amounts –
up to 80%. Try a bar made from 60% cocoa butter and 40% coconut
oil. You might like it!
Shea Butter –HardMild stabilizing lotion-like lather, medium hard, long-lasting bar5-20%Same as cocoa butter. I typically use 5-15% but occasionally will
experiment with using up to 20%.
Castor OilSoftBoosts lather by making a soap more easily dissolved in water5-10%Some soap makers like to use 15-20% castor oil in their shampoo bars or shaving bars.
Avocado Oil – SoftMedium lather, mild cleansing5-12%Avocado oil is a wonderful sub for some of the olive oil in a recipe. It is high in vitamin E and other vitamins and minerals making it a great addition to facial bars or bars for elder skin.
Sunflower OilSoftMedium lather, mild cleansing5-12%Sunflower oil is a wonderful sub for some of the olive oil in a recipe. Use high oleic sunflower for a longer shelf life.
Grapeseed OilSoftMedium
lather, mild cleansing
5-12%Grapeseed is a wonderful sub for some of the olive oil in a recipe.

Soap calculator information

Each oil has its own rating when combined and made into soap. Knowing what each of the pointers are when you use a lye calculator can help you determine and develop a soap that is to your specification or required use.

The list of final properties of soap are as follows.

  • Hardness
  • Cleansing
  • Conditioning
  • Lather
    • Bubbly
    • Creamy
  • Iodine
  • INS

Soap making oil property for Iodine.

Iodine in soap refers to the polyunsaturated fats in a given soap formula and is measured by the amount of iodine that can be dissolved per gram of fat or oil. More information on this HERE.

A good range for Iodine on a soap calculator is below 65.

Soap making oil properties for hard soap.

Oils such as coconut or palm oil help produce hard long-lasting bars of soap, however each also have other effects such as overly cleansing or sometimes creamy.

A good number for a hard bar of soap generally lands somewhere between 29-54. Experiment with these numbers as you make soap and decide what number suits you best.

Soap making oil properties for a cleansing soap.

A cleansing soap refers to the ability of the soap to remove oil, dirt and grime from your skin. The side effect of this is that such a bar would leave your skin overly dry as it strips all the oils from your skin.

A way to combat this overly cleansing bar of soap is to superfat your soap by 10% or more. A good range for a cleansing bar would be between 12-20

Soap making oil properties for a well-conditioned soap.

A better way to think of a conditioned soap is how well does it moisturize your skin. This ability to add moisture to your skin can be achieved by ensuring you always superfat your recipe with a minimum of 5%.

The emollient content of a soap is the technical term, and a good, conditioned bar of soap would be between 44-69.

Soap making oil properties for bubbly soap.

A bubbly soap can be harder to achieve balance than most people think. OfCourse soap has bubbles, but a really bubbly soap requires less soap to do its job of cleaning your skin.

A side effect of this is that the bar of soap tends to be heavy on the cleansing side which means it leaves your skin dry after washing.

This fluffy type of lather is often preferred by person who get soiled more often than not. Make sure you balance this type of bubbly soap with a good percentage of super fat to add moisture back to the skin.

A good range for a bubbly soap on a soap calculator is within a range of 14-46.

Soap making oil properties for creamy soap.

A creamy soap refers to a soap that doesn’t lather as fluffily and bubbly as a bubbly bar of soap. Instead, this type of lather is often low but filled with skin loving moisture.

Creamy later soap is often prefered by persons with naturally dry skin as it helps the skin retain some of the oils that were used to make the soap.

A good range for a creamy lather soap on a soap calculator is within the range of 16-48.

Bahamas Soap Maker

Rashad has been making soaps since the inception of Bahamas Candle and Soap in 2008. Since this time he has taught a number of students how make homemade soap using the melt and pour process or the cold process of soap making. His preference is cold process soap making because of the versatility you have in designing not only the ingredients but the aesthetics of the soap. Soap making became more than a hobby for Rashad and he loves trying new techniques and teaching others how they too can make their own soap at home.

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