How to make natural soap from scratch (cold process)

There are tons and tons of information online on how to make soap, but I still thought I would make a guide of my own, to add what I’ve learned from my years of soap making. The perspective I can add is how to make ‘all Indian’ soap in the spirit of ‘Thinking Global, Buying local’. Keep in mind this is a guide to Cold Process solid soap making.

What is soap?

Soap consist of liquid, fats and sodium hydroxide (lye), mixed together causing a process called saponification. If done in the right measurements there is only soap left once completely saponified.

Fats in soap can consist of vegetable or animal fats. In the context of India I will only be discovering vegetable fats – or better known as oils. Carrier oils or Base oils, to separate them from Essential oils, are measured and mixed according to the property they add to the soap. Properties include cleansing, moisturising, hardness and lather just to mention a few. Even though a few oils can be used as the only oil in a soap, most soaps are made out of at least 3 oils. This is to balance the properties of the soap. I will get into more details when we start planning the soap.

Liquid is typically distilled water, but can also include juices from fruits and vegetables, spirits such as beer, vinegars, milk – and the list goes on. Adding another liquid than water can serve to colour the soap, or to add decided properties. Beer for example adds lather and moisture, vinegar adds cleansing properties, and carrot juice both adds a orange colour and other skin loving properties.

Sodium hydroxide, also known as lye, makes solid soap. It’s not to be mistaken for Potassium hydroxide that makes liquid soap.

These three will make you a simple bar of soap, though the possibilities of added elements is (almost) only limited by your imagination. Today soaping has become an art form, and I promise you if you love being creative as much as I do, this is a great way to satisfy the artistic itch.

For the sake of keeping this simple, I won’t go into how to make a recipe, but simply give an example of one I used recently. Later I will make a separate post on how to make your own. So here is what you need:


  • Carrier oils/butters – Coconut, Castor, Sesame, Sunflower, Neem and Kokum butter
  • Essential oils – Pine, Eucalyptus
  • Additives – Multani Mitti, Activated Charcoal, Aloe Vera gel
  • Sodium Hydroxide
  • Water (note: I just use normal clean water)


  • Rubber gloves (Thick)
  • Safety glasses (covering your eyes completely)
  • Stick blender
  • Pitcher
  • Bowls (plastic or stainless steel)
  • Pot (not aluminium)
  • Spatula
  • Hand whisk
  • Electric scale
  • Measuring spoons (best with millilitres)
  • Soap mould of choice

Note: even though I have heard of soapers that use kitchen utensils for soap making, I prefer to keep them separate. You don’t know if lye is left when you’re cooking in them, so don’t take the chance.

Step 1: Calculate your recipe

I will give percentage for the recipe, so the calculation basically depends on the size of the mould you want to use. The percentages are as follows:

  • Coconut – 25%
  • Castor – 10%
  • Sesame – 10%
  • Neem – 10%
  • Wheat gem 15%
  • Sunflower 15%
  • Kokum butter 15%

Now my mould fits 900 grams of oil, so the oils would be as follows:

  • Coconut – 225 grams
  • Castor – 90 grams
  • Sesame – 90 grams
  • Neem – 90 grams
  • Wheat gem – 135 grams
  • Sunflower – 135 grams
  • Kokum butter – 135 grams

This is the base of your recipe. Now you need to calculate your lye and water amount. Instead of getting into the technical stuff of how this is calculated, I’ll recommend you  to use any of the many saponification calculators available. I use the mobile app called Saponify, which also saves your recipes with dates and notes, so you can keep track of your experiments.

Here is a snapshot of the app:

Untitled design

Picture 1: Name you recipe something that you remember. When you start making a lot of batches using the same recipe, I recommend you start a soap diary with the details of each batch, but we can get to that later.

  • NAOH is Sodium hydroxide, so don’t change that unless you want to make liquid soap which is KOH (Potassium hydroxide).
  • Liquid % of oils is 38 by standard for beginners, but can be modified when you’re more experienced. Soapers put more or less water to control how fast or slow the soap saponifies, giving more time or less time to finish it.
  • Super Fat % of oils is how much of the oil is kept in the soap without being saponified. Usually soapers don’t go beyond 7 %, and in some of the Indian seasons too high super fat can make the soap ‘sweat’ (moisture drops appearing on the soap surface).

Picture 2: The next picture is where you add the oils. Simply press the the plus sign and choose the oils you want in your recipe. You will be putting the oils in grams, which we calculated above.

Picture 3: On the last picture the final recipe has been calculated. Water and NAOH has been calculated for you, and you are good to go.

Step 2: Prepare you work area

Making soap is a chemical process, and that needs to be respected. Cover your work area with newspaper, unless you have a stainless steel surface to work on. Note that lye can ruin soft surfaces, so make sure you got it well covered. If you have kids or pets, make sure they don’t have access to your area. Sodium hydroxide is very dangerous if ingested or if it gets in contact with eyes etc., so I cannot emphasise this enough.

Step 3: Mix up your lye water

I like to start with mixing the water and lye, since it takes some time to react, leaving me time to prepare the rest of the ingredients. Now there are a few important things to keep in mind when you deal with lye. First of all, protect yourself! Lye can make you blind if you get it in the eyes, so wear your safety glasses and gloves. Second, never pour water on lye, pour lye on water. I once read that you should just remember ‘the snow falls on the lake, not the lake on the snow’, and it really helped me in the start to remember. When you have measured out the lye and water, add a spoonful of Aloe Vera into the water, and then pour the lye and stir until its dissolved. Now set it aside.

Step 4: Mix your oils

I tend to mix the oils in the pot I’m going to blend them in, to save on the dishwashing. If using any butters, or coconut oil that hardens in winters, you will need to heat these to make them fluid. Simply measure all your oils on your scale (in grams), and gather them in your pot. Put your pot in a water bath to melt the butter, or melt it separately in a double boiler and add. When all oils are mixed and melted set it aside.

Note: if you are mixing several oils put them on one side on the scale, and move each to the other side once added to your pot. I have several times forgotten which I have already added, having to start over!

Step 5: Prepare the rest of your ingredients

Essential oil is the only thing I don’t measure in grams, but in millilitres instead. Now there are ‘fragrance calculators’ online, but I rely only on my personal experience. I have tried these calculators, but feel like they recommend very small amounts, ending up in a scentless soap. My principal is 15 ml per 100 grams of oils for ‘weak’ essential oils, and 10 ml per 100 grams for ‘strong’ essential oils. How exactly to say if its weak or strong is a bit on the personal experience too, but basically if the smell is fleeting its weak and if it stays in the nose for a long time its strong.

Clays and other additives I very rarely measure out. I just prepare them so they are easily accessible for me to use until it has the colour I want. Though it should be noted that some additives will ‘bleed’ colour if added in access, and others can make the soap ‘scratchy’. Still, the colour depends so much on which other oils are in the bar, so I prefer to have plenty and add as I feel. You can find lots of information online with recommended amounts, if you want to be 100% sure.

Step 6: prepare to make your soap

Soap is all about timing, and once you start making your soap, everything should be ready so you can concentrate on it fully. Otherwise you might risk the soap hardening in your bowl before you pour it in your mould.

I do the following:

  • Put your mould ready on the side
  • Essential oil measured out and put on the side
  • Additives ready with a spoon to add
  • Two bowls to divide the soap when adding Clay and Activated charcoal
  • Blender plugged in and a clean surface to rest it on between blending
  • A whisk ready to hand whisk if you need to slow down the process
  • A spatula to get the last soap out of your bowls
  • An extra mould – if the soap gets too hard to pour, I have an extra mould where I put the remaining, and then use these for hand wash at home. Could be little heart shapes for example. You can also intentionally make a little extra and use these to send out as samples if you want to make soap for business.

Step 7: Mix lye in your oils

Now, this is what you came for. Disclaimer: many soapers say you should measure the temperature of the soap and lye water, and mix them when reaching a certain temperature. I have stopped doing that after reading a lot of soapers that didn’t. I simply wait until my lye water becomes clear (transparent). When it does – you’re ready to make your soap. Pour you lye water into your oils while slowly stirring. When all the lye water is poured, emerge your stick blender fully and start blending. Make sure not to let it surface since it will splatter if you do. Now you need to pay attention to the texture of the soap mass. The time to pour your soap is called Trace, which is when the soap mass has thickened enough for the stick blender to leave a little mark when you lift it. Since you will be adding additives, stop blending at a thin trace. This is when the stick blender leave a mark when lifted, but the mark immediately disappears. When you reach this stage, go to next step.

Step 8: Add your essential oils and additives

At this stage add your essential oil, and whisk with your hand whisk. After its completely into the soap mass, divide the soap into two bowls. Now add your clay to one and activated charcoal to the other. When they have the colour you desire, you’re ready to pour your soap.

Step 9: The bowl swirl

Swirling is when you mix different colours of soap masses into a pattern. It’s a fun way to get creative, and keep developing your skills. The bowl swirl is one of the easiest I have come across. You simply pour one colour into the bowl on the other, and then pour it in your mould, making it swirl in different patterns.

Note: the two colours have to be contrasting. Otherwise it won’t be very visible in the soap.

Step 10: Pour your soap

Pour your soap carefully into the mould. You can use the whisk to make little shapes on the top of the soap. Set it aside to harden. Another thing I don’t do, is to pack my soap in a towel to get it into gel phase. Gel phase is when the soap turns gel like as a part of the process. This happens when heat is added, hence many pack it in old towels to make it warmer. Some soapers like it better after gel phase, because the colour changes a bit, but it doesn’t matter for the soap itself. I often experience the soap goes through gel phase here in India without doing anything, because the temperature is naturally hot.

Step 11: Wait, cut and cure!

Cold process soap needs to cure for min. 3 weeks. Depending on the oils and mould, it will be hard in everything from 1 day to 3 weeks. When completely hardened, you can un-mould and cut it – but you will still need to set it aside. The longer a soap cures, the harder and gentler it gets. For shampoo bars min. 6 weeks is recommended, for face and body bars 4 weeks minimum.

Now, you have made your first soap. Do let me know if you have any questions, tips or experiences!


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17 thoughts on “How to make natural soap from scratch (cold process)”

  1. Wow, Louise, seems like we are Soap Sisters! 🙂
    I have experimented and learnt-by-doing for about 3 months or so, and have come to pretty much the same conclusions as you do. So much fun! So far, I am developing three different soaps, which are currently being tested on real life human beings, mostly female, of the DNS type.

    One is a castile soap, which my saponification calculator claims to be an absolutely fabulous mix:
    78% olive oil, 17% coconut oil and 6% castor oil. (Superfat 7%) I use apple cider vinegar as liquid, and add a spoonful of coconut syrup to the lye solution. Sugar is said to improve the bubbles, but I can’t really tell.

    The other recipe is my “33/11” formula, with olive oil, infused with flowers… dandelions are fab, or lavender or calendula. We have loads of lavender in the park, so I have some soaking right now.
    I like this recipe because I can buy all ingredients in our local Netto (except the castor oil).
    So this is the lavish 33/11 soap formula: Olive oil 33%, Coconut oil 33% Macademia nut oil 11% Avocado oil 11% , Castor oil 11%

    I have found that this soap bar also makes an excellent shampoo, and my otherwise flat, dull, hair-product- needy hair is now in a better, natural, volumised shape because I use this soap. No conditioner, strong-hold foam or styling wax needed ever again!

    The third recipe is much like yours, actually, with coconut, sesame, sunflower and castor oils, but with shea butter instead of your ingredients. And clay that I got from a Portuguese woman. It is grey and very humble looking, but the lather is so smooth .

    I look forward to following your blog and see what else we can share of ideas.

    Have you tried to make skin care products?


    1. I didn’t even see this till now!!!!!!! I’m so happy to hear from you. Have been thinking about you. Want to make a proper reply so let me do it a little later. Just wanted to send a hug.


  2. Wow..this article explained me basic concept of cold process soap making..after watching soapyqueen videos, i think this one explains me theorically very basic of soap making.
    Can you please explain the concept of trace with pic if possible. Thank you!


    1. I have a supplier I got through a Facebook Group called Soap Making India – I’d be happy to invite you to the group, or give you the mail of my supplier. You can contact me on


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