Creating your own soap recipe is one of the most exciting parts of soap making! It gives you complete control over how your soap looks, feels, and performs, but knowing where to start can still feel overwhelming.
This guide is designed for soap makers who already understand the basics and are ready to start formulating their own recipes. If you are a beginner soap maker, read our guide to soap making first!
In this blog, we’ll break down the process step by step, explaining how different oils and butters affect your soap and how to calculate the right amounts.
Contents
- Why Formulate Your Own Soap Recipe?
- Which Oils and Butters Should You Use In Soap?
- How To Calculate The Oils
- How To Calculate The Water
- How to Calculate The Lye
- Customisation
- How a Finished Recipe Should Look
- Test Your Recipe
- Final Thoughts
Why Formulate Your Own Soap Recipe?
Formulating your own cold process soap recipe gives you full control over every ingredient, allowing you to tailor each bar to meet specific skin needs.
When following soap recipes online, there is always at least one ingredient in there that we don’t want to use. If you create your own soap recipe, you can use all of the ingredients you love and keep those unwanted ingredients out!
Creating your own soap recipes also lets you experiment even more with your soap making, from trying different oils and butters to incorporating unique ingredients like tea!
Which Oils and Butters Should You Use In Soap?
There is a huge range of oils and butters you can use in your soaps and each one will have their own benefits.
We would recommend starting with oils and butters that are commonly used, before experimenting with unique ingredients.
Here’s a list of the most popular liquid oils and their benefits in soap making:
- Olive oil - This is the most popular liquid oil in soap making. It is used to add a lovely conditioning feel to the soap bar and to moisturise the skin.
- Castor oil - This is the best oil if you want a good lather! But don’t add over 5% to your soap, as too much castor oil will make the soap feel sticky.
These two oils are all you need to make a good, high quality soap. They are the most reliable and most commonly used for soap making.
However, adding other oils add extra benefits to the soap! If you’d like to experiment or make the soap feel more luxurious, you can also include other oils. Some oils you can try are argan oil, sweet almond oil, hemp oil, or apricot kernel oil.
We recommended adding the extra oils at around 5% of your recipe as a superfat. So these oils will add their moisturising benefits to the superfat. However, it is important to note that you cannot control which oils and butters will be left as superfat.
Here’s a list of the most popular butters and their benefits in soap making:
- Coconut oil - This is the most popular solid oil for soap making as it creates a hard soap bar. It also adds a lot of lather and cleansing to the soap. An alternative to coconut oil that we love is babassu oil!
- Tallow - This is great for making a hard soap bar. It also adds a lot of creaminess and conditioning to the soap. You can also use lard in your soap for similar benefits.
- Palm oil - This oil provides both cleansing and conditioning to a soap bar. It also adds hardness to the soap and a creamy lather. We know palm oil is a controversial ingredient, and we understand if you don’t want to use this in your soap. We can assure you our organic palm oil is certified as sustainable by the Roundtable on Sustainable Palm Oil (RSPO).
- Cocoa butter - This is great for creating a hard soap bar. It also adds a creamy and conditioning lather to the soap.
- Shea butter - This is a great oil for added moisturising benefits and it adds creaminess and conditioning to soap. We recommend adding around 20% shea butter as it does not add lather to the soap.
How To Calculate The Oils
Once you’ve decided which oils and butters you want to use, you can work out how much to use in your recipe.
To start your soap recipe formulation, we would recommend following these guidelines:
- Hard oils: 60% of the total oils
- Liquid oils: 40% of the total oils
You do not have to follow this exactly, but it is a good place to start.
We use 800g of oil in our soap recipes, as the full soap mixture fills a loaf mould perfectly.
Here is an example of how this might look:
60% of hard oils:
- Tallow 240g / 30%
- Coconut oil 240g / 30%
40% of liquid oils:
- Olive oil 280g / 35%
- Castor oil 40g / 5%
How To Calculate The Water
The water should be calculated as a percentage of the oils. The recommended range is between 28 - 38%, with most soap recipes using between 30 - 33%. In our soap recipes, we usually use 30% water.
You can use more or less water in your soap, but it will have a slightly different affect on the soap. More water will mean the soap takes longer to cure. Whereas, less water may make the soap harder to work with. The less water you use, the hotter the lye solution will be so be careful!
How to Calculate The Lye
Once you know the oils, butters and water amounts, you can put that information into your soap calculator and this will then calculate the sodium hydroxide for the recipe. For our cold process soap recipes, we use soap calc.
If you want to get a good understanding of how the lye amounts are calculated, read our blog about SAP values!
How to Use Soap Calc
1. Type of Lye
In the top left corner, you’ll find the first step. All you have to do is select which type of lye you are using. NaOH (Sodium Hydroxide) or KOH (Potassium Hydroxide). For cold process soap making you need to use sodium hydroxide, so we have selected NaOH.
2. Weight of Oils
For this step, you need to select the unit of measurement you will be using. We always use grams, so we have selected that. Then in the box below that, type in the total amount of oils in the soap.
3. Water
In this section, just type in the percentage of water you would like to use. We use 30% water as a percentage of oil, so we would type 30 into this box.
4. Superfat and Fragrance
You don’t have to superfat your soap, but we do recommend it!
Superfatting soap to 5% gives the soap a moisturising feel and it can also give you a margin of safety! If there’s a small measuring error with the lye, whether from human error or slight scale inaccuracy, the superfat helps prevent the soap from becoming lye-heavy.
If you want to know more about superfatting, read our blog: What is Superfat in Soap Making?
If you are including superfat in your recipe, type in the superfat percentage.
For fragrance, you can type in the specific amount you want in your recipe. We usually leave this at 31g.
5. Oils, Fats and Waxes
This is where you choose the oils and butters you want in your recipe. Simply scroll through the list and find the ingredients you want to use.
6. Recipe Oil List
Now we need to list out the oils and butters we are using and the amounts.
First, click on the ingredient you want to add from the list. Then click on the + and it will add it to the recipe oil list. Make sure to do one ingredient at a time. To remove an ingredient from the list, just press the -.
Then select either the % column or the measurement column depending on which you would prefer to use. Then type in the amounts you want. Here’s our example:
7. Calculate Recipe
Underneath the recipe oil list, you will see a button that says ‘calculate recipe’. Click this and then click the button underneath that says ‘View or Print Recipe’.
This will produce something that looks like this:
You should focus on the two sections we have circled in red. These tell you the exact amounts for your recipe.
Customisation
Now you know how to formulate the oils, water and lye in your soap, you can think about the essential oils, colours and extras that can go into your soap.
Essential Oils
In most recipes, it is recommended to use up to 35g of essential oils for 1kg of soap. We usually add around 2% essential oils to our soap.
However, this does not apply for every essential oil! Before adding essential oils to your soap, you need to check the usage rates for each scent you are adding.
You can find the usage rates for every essential oil on an IFRA document. When looking at the IFRA for your essential oil, look for category 9 (this is for soap products) and check the usage rate percentage.
For an in depth look into essential oils in cold process soap making, click here!
Colourants
If you want to add colour to the soap, you can use natural mica powders. Choose from our range of mica powders here! Natural colourants like paprika, turmeric, madder root and walnut powder can also be used to colour soaps.
The amount of natural colourant you use varies between each colourant. For mica powders, it will depend on the strength of colour you would like.
The maximum amount of mica powder we would recommend is up to 3% - 5%. However, you shouldn’t need to add this much to reach a strong colour in your soap. We usually add around 1% of mica powder to our cold process soaps!
Extras
There is so much more you can add to your soap recipes from botanicals and clays to waxes and salts!
However, you need to be careful when adding extra ingredients, as some may have an adverse effect on your soap.
But don’t worry, we’ll talk you through how much we recommend adding for the most popular extras:
Beeswax - Beeswax must be used in a low percentage of your recipe, as too much can reduce the lather and make the soap feel waxy. We recommend using around 1% to 3% beeswax in the soap.
Clays - Too much clay in soap can cause the soap to become brittle. There are no set rules when adding clay to soap, but it is recommended to start at 1tsp of clay per 1 pound of oil (which is about 5g of clay per 453g of oil). You can then experiment adding more clay, but just be aware that the soap will get thicker and more brittle as you go.
Salts - There are no set guidelines for adding salt to soap, but you must be sparing! Adding salt to soap will make a very brittle and hard soap bar that can be drying on the skin. So start small, and add more if you think it needs it.
Botanicals - Adding botanicals to your soap won’t affect the quality of the soap at all. But you may find they oxidise and turn brown after a while.
Milks - You can add either liquid milk or powdered milk (like our goats milk powder) to soap. There are no set usage rates for milk in soap. You can even make a 100% milk soap.
Juices - Juices should be added in small amounts. There are no set guidelines, but you could start with 1 tablespoon of juice in 500g of soap. Too much juice can disrupt the saponification process and it can also increase the likelihood of mould and bacteria growing.
Aloe vera - We recommend using aloe vera powder in soap as it is pure and concentrated. The recommended usage rate for this is 0.1% to 1%. If you are using aloe vera juice, you can replace the water with the aloe vera juice.
Teas - There aren’t any set usage rates for tea in soap as it will be infused into the water and strained.
How a Finished Recipe Should Look
Your recipe will look different to ours as you’ll be using different oils and you may want to add some extra ingredients, but if you want to check if the basic elements of your soap recipe are correct, then have a look at our example.
Test Your Recipe
Now you have created your soap recipe, you will need to test it!
Don’t worry if it doesn’t turn out exactly as planned, this is all part of the process. Use your results as a guide to tweak and refine your recipe where needed.
Here’s some ideas to fix common problems:
Soap is too soft - You might have too many soft oils in the recipe. Consider reducing the amount of liquid oils or add more butters that harden the soap like coconut oil.
Soap is too hard - There may be too much coconut oil or solid butters in your recipe. We would recommend trying to reduce the amount of butters and increase the liquid oils.
Not enough lather - The oils you have chosen may be the reason the soap does not have much lather. Try adding some new oils that are known for increasing lather like castor oil.
Soap is too drying - If you haven't included a superfat in your soap, try including this for an extra moisturising effect.
Struggling with more soap problems? Read our cold process soap making troubleshooting blog!
Final Thoughts
Creating your own soap recipe gives you the freedom to create soaps that truly suit your preferences, from the oils and butters to colours, scents, and extras.
While it may take some experimenting, once you understand how each ingredient works you will have full control of the final result!
So don’t be afraid to test, tweak, and refine your recipes. With practice and confidence, you’ll be creating beautiful, custom soaps that are uniquely yours.
Continue Reading
Now you know how to make your own vapour rub, why not continue reading?
- Not sure where to start with soap making? Read our guide on how to make soap!
- Want to learn how to formulate your own melt and pour soap recipe? Read our guide to melt and pour soap making!
- Interested in making a unique soap? Check out our grapefruit soap recipe to see how we incorporated juice into soap!
Did you enjoy formulating your own soap recipe? Show us the recipe and how the soap turned out! Tag us on Instagram or Facebook or use our hashtag #thesoaperyuk
