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Cold Process Soap Making Method & Easy to follow Recipe


Castile Soap Making Kit
Our Natural Soap Making Kit This Pack = Castile Soap Kit


I’d just like to point out that I’m NOT the be all and end all – when it comes to natural soap making.  This is how I make soap and other persons may find it useful, if you are embarking on a journey to reduce the chemicals in your home and opt for a more environmentally friendly, healthy alternative to nasty commercial soap products on the market.  This is how Natural Soap has been made for centuries and is called the ‘COLD PROCESS METHOD’.  It uses natural ingredients to create soap that is actually GOOD FOR YOU.  People that suffer with allergic reactions to detergent based soap, surfactants and God knows what in the commercial kind – will find this natural soap a ‘RAY OF LIGHT’.  Many folks enjoy the process immensely and become very artistic too.  It’s basically wholesome goodness in a bar of soap.  It’s nourishing and cleanses beautifully.

Soap Making is a very rewarding and relaxing hobby. I have put together some basic soap making techniques and principles for the beginner to experiment with.

What is happening when we make ‘soap’ in basic language.

1. Basically – a chemical reaction called ‘Saphonification’ takes place between the oils and the alkali called ‘Lye’.

2. So you must follow basic guidelines and use the correct measurements of oils vs alkali to make this reaction happen.

3. You must then wait for the saphonification phase to complete before you use the finished product.  This usually takes about 4-6 weeks.  It’s important to wait this period of time before using your soap, so that it becomes mild and lasts well too.  Soap used before it’s cured properly, will be rather harsh on your skin and will waste too, it’s certainly best to allow it to harden, during the initial cure of 4-6 weeks.

So what do we need to make soap?

First of all we need to consider safety.

An accident is never planned for, but we can plan for it and protect our most valuable assets. You will be working with and arround caustic liquid. Splashes and spills can happen. So we need to be prepared for the event.

1. Googles (Eye Protection)

2. Face Mask (Fumes)

3. Glooves & Apron


1 x Digital Scales that measures in 1gm increments.

2 x Thermometers that will read temperatures commencing at 25 Degrees Celcius/90F

(One is for the Lye Mixture and one is for the Oil Pot)

1 x Jug for mixing and holding lye solution while cooling

Measuring Cups/Spoons and droppers for measuring essential oils and additives

Old Towels

Mould (enough to hold your mixture – my recipes are all 1kg)

1 Large Pot (enough to hold your oils and liquid mixed together)

1 Stick Mixer

Basic Soap Making Ingredients

1kg Oil of your choice (read up on the different properties of oils and design your own)

There are many recipes available for use on the internet, just find a basic recipe that you like to start with.

The recipes I have included here are what I use in my soap creations, I don’t sway too much from these recipes as they work and can easily be changed by changing the essential oil, additives and colour.

Caustic Soda – You will need to multiply the weight of the chosen oil by the saponification value to find the weight of the cuastic soda required eg. 1000grams olive oil – .134 x 1000grams = 134 grams caustic soda. Allow around 5% less so that your soap is more moisturising).

380 grams water @ 38% of Oil weight

Essential Oil 2-3% of Oil weight

Botanicals (Lavender Buds, Rose Petals, Spices) the amount is your choice.

You can also add (Cosmetic Clays and Exfoliating Additives now), please read up on what these ingredients are used for).

So we are going to make a basic COLD PROCESS soap recipe…….there are different Methods.

The recipe we will use here is a very basic CP Recipe:-

500gms Olive Pomace Oil
250gms Palm Oil
250gms Coconut Oil

145gms Sodium Hydroxide
380gms Water

25ml Lavender Pure Essential Oil (This is 2.5%, based on the weight of oil used)
Lavender Buds to Mix through

Here’s another recipe for those that would prefer not to use Palm Oil –

600gm Olive Oil

400gm Coconut

146gm Caustic Soda (this allows for a 5% reduction in Caustic, so the soap is more nourishing)

380gm Distilled Water

Add 3% Essential Oil of your choice (at Trace)

This will make a batch with a total weight of approx 1380gm.  So, you’ll need two (2) x 1Ltr Waxed Milk Cartons to hold this quantity.

If you’d like to purchase a kit that has everything you’ll need to make this Traditional Natural Soap GO HERE to BUY a Natural Soap Making Kit.

Steps to follow –

Collect all the ingredients and equipment that you are going to use during the process
Line your mould with heavy film now (glad bake is great), and have it ready
When you are ready to begin, put on all of your personal protection equipment
Take your time and DO NOT be rushed when you are going to make your soap.
Relax and take your time

Measure the Oils using digital scales for exact measurements

Place pot directly onto your scales and zero out the weight so that it will start weighing from zero.
Weigh out the required quantities of solid oils, straight into the pot that you will be using on the stove.
Set aside while you prepare the lye solution.

Before starting to heat your oils……Prepare lye solution

Measure out the water into the jug that you are going to use to make your lye solution, on the scales. It must be by weight.
Then measure the caustic soda the same way, and add the caustic to the water, always add the caustic soda to the water and never the other way around.
Add the caustic soda in one steady slow movement and stir very slowly to combine. At this stage the solution will heat very rapidly and now needs to be put on a window sill or outside to cool down, to 60 Degrees C, once cooled and at this temp. you can bring the solution back to your immediate work area. This could take up to half an hour. (You can speed it up in a cold water bath if you want to). Always keep in mind that you must check on the temperature of your lye solution, at the same time as checking the temperature of your oils if you have them happening at the same time. For your ease of learning – we are doing the two components somewhat seperately.
Be very careful not to splash the solution onto yourself. In the event of an accident you can neutralize the caustic with white vinegar. Use the vinegar directly on yourself and on any effected work area. To stop any burning sensation experienced.
Once you have the caustic soda mixed into the water, this is called ‘Lye’

The trick is, you need to have these two things – Oils and Lye Solution, happening at the same time as you become more experienced, you need to balance the temperatures before adding the ingredients together. This balancing is the key. Take your time with both mixes and be patient. With practice you will become much faster at this and you’ll learn how to do the two things at the same time, which in effect makes the whole process faster. Once you’ve done it this way and understand the process, you’ll also develop your own ways of doing things.

Take the solid oils that you measured out first (Palm and Coconut Oils), and place onto the stove and slowly start to warm these two oils until liquid.
Now measure out the Olive Oil and add it to the Palm and Coconut Oil once they have become liquid. We melt and liquify the solid oils first, so as not to unnecessarily overheat the liquid oils. You can add them all together from the start if you want, in my experience – it just takes longer.
Remember the total weight of all oils needs to be 1kg for this recipe.
Continue to heat the combined oils to approx. 50 Degrees C using your thermometer to keep check. Vary the temperature control and even turn the temperature off the oils, if you think that you need to slow it down. DO NOT OVERHEAT YOUR OILS, YOU’LL NEED TO COOL THEM DOWN BEFORE PROCEEDING IF YOU DO. A COLD WATER BATH IS GOOD FOR THIS.

I have found that the best temperature to combine the two parts is to have the oils at approx. 40-50 Degrees C and the Lye Solution also at 40-50 Degrees C. Remember it is easier to control the temperature of the oils.

Be guided by the speed at which the Lye is cooling down.

You can not reheat the lye solution if it becomes too cold.

There is lots of speculation over the correct temperatures. For this recipe, these temperatures work. You can experiment yourself over time with what works best for you. If your lye solution cools down too much, continue on and simply allow your oils to also go cold and at the same temp. continue on even at a very low temp. If you can reach trace you’ll be fine.

NEVER COMBINE YOUR OILS AND LYE WHEN THE HEAT IS OVER 60 Degrees C. It is also ok to have the two components within 5 degress C of each other, they don’t have to be exact.

When you have balanced the temperatures of the oils and lye you can add the lye solution to the oils, again in one steady slow stream. You will see the lye solution sitting on the bottom of your pot, immediately start to mix and combine which will in turn take the mix to a cloudy oily consistency. Begin to mix with whatever you’re going to use, I like to initially use a long handled spoon or whisk to initially combine the lye with the oils.

Then take your stick mixer and mix in slow 20 second bursts, being very careful not to splash the mixture everywhere. YOU CAN CONTINUE TO MIX BY HAND – IT WILL TAKE LONGER TO REACH TRACE, A WHISK WILL GET YOU THERE IN APPROX 10 minutes. Some recipes can take up to 50 minutes if mixing by hand.

My favourite is a Stick Mixer – It will only take a few bursts with a stick mixer and you will see the mix begin to thicken and become a thick creamy consistency, this is what we call “Trace”. It looks something like a pancake consistancy – you can draw images on the top of the mix before it dissapears into the mix again. At this stage put down your mixer and begin to add your essential oil or fragrance and any other things that you want to add to your soap. There is no colour added to this recipe, but if you wanted to add colour you would do it now. I recomend using natural colourants in CP Soap to keep it natural. Things such as cinnamon, spice, tumeric, honey, oatmeal, cocoa.

You will need to add 20-30mls of Essential Oil, or up to 100mls of Fragrance Oil (Lavender Essential Oil for this recipe, so as to keep it natural)


And if you want you can add lavender buds to the mix and stir through, or you may like to sprinkle the lavender on top after it is in the mould. You will need to work quickly at this stage as your mix will continue to saphonify and become very thick, it is best to get it into the mould quickly.

Once your additives have been mixed through you can carefully, but working quickly at this stage, pour the mix into your mould that you have previously lined and have ready.

Even out the mix in the mould and cover with a lid and some towels, like a baby, to ensure that your soap doesn’t cool down too fast.

Leave the soap in an out of the way spot, for 24 – 48 hours.

You can then unmould your soap and slice into bars.

The soap will be soft at this stage so you need to take care. The soap is also still caustic to touch and should be kept in a secure location away from little fingers.

Allow your soap to harden and cure for at least 4 weeks, the longer the harder the bars will be.

So this is a basic cold process soap recipe that you can experiment with and enjoy.

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