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How to Create a Soap Recipe

Soap Recipes

I have realised over the years that so many of my clients have loved the Soap Making workshops, gone on to make soap at home for friends and family, loved every moment of it and then decided they wanted to create their own bespoke soap business – hence my One to One Business Counselling workshop was formed. This workshop helps my clients take that next step, apply for Safety Cosmetic Assessments and start up a unique business with an aim to making a very good profit.

I know that some people are happy using the first recipe they were taught in the workshop as it makes a fantastic soap that’s also great for the skin in the bathroom, shower or kitchen but many of these entrepreneurs finally want to create a recipe that’s unique to them and their business. If you are one of those people this step by step guide below can help put you on the right track and hopefully stop you wasting precious profit, time, energy and heartbreak.

Grab yourself a pen and some paper or notebook, cup of coffee and sit somewhere relaxing and quiet.

Know your product

Write down what you want in a bar of soap, what it must be capable of doing and what it needs to look like.

Is it to be a nourishing, moisturising soap, a soap that will help skin complaints, a baby soap, a soap intended for people who hands are dry and cracked i.e. nurses or gardeners or just a soap that looks lovely and smells lovely.

How much of lather do you require.

How much do you want this soap to cost – is it a bar for everyday use or is it a luxury, bath soap that will lift your spirits and make you feel good every time you use it and you refuse to let anyone else wash with it.

Choosing Oils/Butters

Once you have decided on the product you want to make you now need to look at different oils and butters to see if they contain the properties you will need for your soap. Write each one down and then by the side list all of the properties each one contains, delete each oil/butter that does not provide you with the properties you need for your soap and keep all the ones that do.

Now look at each oil/butter you have remaining on your list and see if they are easily sourced and reasonably priced - there is no point choosing one that is so expensive to buy that each bar of soap would cost you more than you can realistically charge for.

INS Value – Iodine Number Saponification Value

In the 1900’s scientist developed a rough way to predict the ‘hardness’ of soap when made with certain oils and butters and they came up with this INS value.

The iodine number is how much unsaturated and oil is and the saponification value is used to work out how much lye is needed to convert the oil to soap.

The INS value is saponification minus the iodine number. Values range from a zero number to over 250. A value to achieve for a good soap is 145-160.

The higher the number the harder the soap.

So, now you need to place each INS number beside each of your chosen oils/butters.

Google is a great place to find out INS values, just put in your oil/butter and ask away.

Deleting Oils/Butters

Start to whittle down your list until you have approximately two or three really great ones that are great for the skin, readily available, reasonably priced and will produce a great soap.

Your Mould

You need to know what mould you are going to be using and how much this mould will hold. No good making 1,000gms of soap and your mould or moulds only hold 750gms! Once you know this you will know how much you are going to make.

Working out your INS value

Once you have chosen your oils/butters and your mould and you know how much you are going to be making you can now do some simple mathematics to see if your soap will actually ‘work’ and the correct ‘hardness’ can be obtained. Remember a good figure to be working towards is 145-160.

Achieving your recipe

The example below will show you how to work out if your chosen oils/butters will produce a good soap.

Soap using Grapeseed oil, Coconut Butter and Shea Butter

Mould holding 900g.


Grapeseed oil x 250g (INS value of 66)

Coconut oil – refined x 250g (INS value of 248)

Shea Butter – refined x 200g (INS value 112)

Total weight – 700g which will fit into my mould.

Divide the weight of the oil/butter by the total weight i.e

Grapeseed :

250g divided by 700g = 0.4

Multiply this number by the INS value (round up)

0.4 x 66 = 27

Coconut oil

250g divided by 700g = 0.4

0.4 x 248 = 100

Shea Butter

200g divided by 700g = 0.3

0.3 x 112 = 34

Add all totals together

27+100+34 = 161

Although just 1 over you can see this will make a really good soap

Your Lye

Now you have your oils/butters you now need to find out how much Sodium Hydroxide and how much liquid you will need.

This is so easy as we now have soap calculators that do this job for us. Use an easy one like the Brambleberry or SoapCalc and go through their step by step information and your recipe will be displayed for you complete with Sodium Hydroxide and liquid amount.

If you need any more help on creating a new soap recipe please get in touch.

Happy formulating

X Diane

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