How To Make Liquid Soap – Traditional Lye-Based Liquid Soap Making Recipe

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I’ve recently investigated making DIY liquid soap in a few different ways, and I have to say I’m beginning to become a little hooked. If I’m honest, it’s something that’s been alluding to me for a while now.

As you know, I love making soap, so I decided to take the plunge and have a go at the most traditional liquid soap-making process, and I’m so glad that I did.

Here’s how to make liquid soap at home! 

natural homemade liquid soap

Traditional Lye-Based Liquid Soap Making

If you are familiar with making cold process or hot process you shouldn’t find liquid difficult, however, that’s not to say that you wouldn’t be able to make it if you haven’t, you may find it a little more taxing that’s all.  

I’ve chosen simple but effective oils that are easy for a beginner to work with and are suitable for all skin types. No surfactants here to irritate my skin, just nourishing creamy soap packed full of moisturizing oils. 

You can, of course, choose your own carrier oils and cosmetic butters to make some wonderful unique natural liquid soap using our very own calculator here at SavvyHomemade.

You can use this for shower gels, body wash, hand soap, shampoos, and even bubble bath. It can be packed with many vitamins, minerals, and cleansing properties.

If you have young children try my liquid castile soap recipe, this is mostly olive oil, with a little coconut. It’s gentle, nourishing, and great for mother and baby, or anyone with sensitive skin.   

Below is the video of how I make my liquid castile soap, it’s the same process, the only difference is the oil ingredients.

Watch How To Make Homemade Liquid Soap  

Oils For This Liquid Soap Recipe

Castor oil

Castor oil is rich in ricinoleic fatty acids which gives a longstanding fluffy lather with lots of moisturizing properties.  

Coconut Oil

The Coconut oil also has good lathering qualities and helps to lighten the finished color making it a little clearer.

Olive Oil

Olive oil doesn’t give much of a lather however its moisturizing and conditioning properties are second to none and it also gives a lovely silky feeling on the skin.   

Liquid soap making - how to make bottles of lush smelling totally natural liquid soap


The recipe shows almost 2 days to make this soap, but remember that most of the time is not really active, it is spent waiting for the processes to complete.

Stage 1: Making The Soap Paste  The soap paste in this recipe will take around 6 hours to cook depending on the heat setting on your crockpot. 

Stage 2: Dilution  Stage The dilution time usually takes around 24 hours, you don’t need to do anything to it during in this stage, however, it’s almost impossible not to give it a quick stir now and again.   

Homemade liquid soap

How To Make Liquid Soap At Home

After a few weeks testing and perfecting the process of liquid soap making, I'm now the proud owner of several colorful bottles of lush smelling totally natural loveliness.

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Prep Time: 30 minutes
Active Time: 6 hours
Diluting Paste: 1 day
Total Time: 1 day 6 hours 30 minutes
Yield: 16 Bottles (approx)
Difficulty Level: Intermediate
Author: Angela Wills

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The Oils

The Lye solution


Making The Soap Paste

  • Weigh out all the oils and place them in the slow cooker, set the cooker on low to warm them up and melt them. You can quicken this process by melting the coconut oil in the microwave first.
    600 grams Olive Oil, 105 grams Coconut Oil, 45 grams Castor Oil
    how to make liquid soap 1: Melt your oils and butters in a crock pot. You can save time by microwaving them instead
  • Make sure you are working in a well-ventilated area and wearing your protective clothing (apron, gloves, and glasses).
    When you’re ready, prepare the lye solution by weighing the water and potassium hydroxide into separate containers. Carefully add the potassium hydroxide to the water and stir until dissolved, so that you are not inhaling any fumes you may want to turn your head away from it as you stir. As this is an alkali that can cause serious burns.
    Place the lye in a safe and secure place where it won’t be knocked over until its fully dissolved and clear.
    429.63 grams Distilled Water, 143.21 grams Potassium Hydroxide KOH
    how to make liquid soap 2: Add your lye to the water to make the lye solution
  • Once the oils have fully melted give them a good stir to make sure they are well combined. Keeping the slow cooker on low add the lye solution. There is no need to wait for it to cool as you do when making solid cold processed soap.
    When ready, pour the lye solution into your oils
  • As always I prefer to start mixing manually with a spatula for the first few minutes before changing to an electric hand blender. Always be cautious and remember to give the blender a quick blast before using it just to release any trapped air bubbles.
    Using a stick blender, bring your batter up to trace
  • Using the electric blender bring the mixture up to a light trace. Once you have reached a light trace you will need to bring it up to a nice thick one, so that it looks a bit like mash potato.
    This may take a while depending on the speed/power of the blender and the oils you have used so be prepared for it to take anywhere between 10 to 30 minutes. As you don’t want to fry your blender try blending in 1 or 2 minute blasts.
    Once you've allowed the mixture to cook, it will begin to look like mashed potato, let it cook further
  • When you have reached the mashed potato stage it’s time to let the cooker do its bit, so pop the lid on and let the mixture cook. This could take around 4 to 7 hours depending on how hot your slow cooker gets when it’s set on the lowest heat setting. If you have a warm setting this may be a better option.
    Keep the lid on and stir every 15 minutes
  • As your soap batter cooks it will need stirring every 20 to 30 mins. You may notice the it go through various stages whilst it’s cooking, the final result should be a glossy golden translucent color similar in texture and look to Vaseline but not in color. This is what we call the soap paste stage.
    If you are not sure if it is fully cooked and ready for diluting there is a quick test you can do. Take a teaspoon full of the soap paste and mix it with 25g of distilled water, as the soap dissolves the water should just be fairly clear or just a little cloudy.
    If it’s very cloudy give it another 30mins cooking and test again. It’s worth mentioning that the water in your test will only go clear when using distilled water, any other type of water can result in remaining cloudy.
    At this point, you can move to Part 2 (dilution) right away or you can leave the paste to sit in the crockpot overnight and deal with it the next day. Just make sure the crockpot is turned off and the lid is on.
    You'll know when to move on once your batter becomes a thick, glossy, amber mixture

Diluting The Soap Paste

  • You can now choose to dilute some of the paste and store the rest for a second batch later. Just make sure that any paste you are saving is stored in an airtight container for later. The paste will last for up to one year if kept in the fridge and can be diluted when you need it in exactly the same way.
    Deciding how much water to add to your paste to thin it down can be a little tricky as many different oils and butters require more liquid than others. Although you can thicken the soap if it is too thin, it’s much easier to get it right the first time.
    I usually work on a ratio of 1 to 2, so if I have 700g of paste I will dilute it with 1400g of water. You can do this by placing a container on the weighing scales and setting them on zero before adding the soap paste. Once you have the correct weight (700g) place it back into the slow cooker and weigh out double the amount of hot distilled water (1400g).
    2 liters Distilled Water
    Now we need to dilute it. You can add your water directly to the crock pot
  • Once you’ve added the water to the paste, give it a good stir, it will at this point feel a bit like you are pushing it around the pot rather than stirring it. Then put the lid on the slow cooker and turn it onto the lowest setting for around an hour.
    You can leave it on for longer but you will need to keep an eye on it and give a stir now and then. The soap could take a good 24 hours to dissolve so you do need a bit of patience here.
    Never be tempted to leave the cooker on overnight, the soap will continue to dissolve in the water even without the heat, it just takes a bit longer.
    Allow your mixture to fully disolve
  • Don’t worry if skin begins to form on the top of the soap, this is just undiluted soap and it can be moved to one side so that the diluted mixture bellow can be poured into a fresh container.
    You can then add a little hot distilled water to the skin and leave it to dissolve. Once the soap has dissolved it should be the color of the liquid oils you have used. If it’s too thick, add more distilled water until you are happy with its consistency.
    You will have no visible lumps left once it has dissolved
  • Now it’s time to PH test your soap. If you have cooked it long enough and measured the ingredients accurately it should be between 6 to 9 (green) when you dip a PH strip into it. This is a good level and is now ready for color and fragrance. If it’s not then you will need to lower the PH value.
    To neutralize the soap and give it a lower PH value, mix 14g of citric acid with 56g of boiled distilled water. Adding this should bring the PH level down, but it can make your soap cloudy and also give a temporary curdling effect. Give it a good stir then leave it alone to settle for a while.
    Be sure to test your liquid soap to make sure it is at a safe PH level
  • Adding a preservative is always controversial, as the soap has a high PH you don’t need to add a preservative however if you are likely to be keeping it in the bathroom or selling the soap, I would recommend adding one. This will also extend the self-life from 6 to 18 months.
    Add the preservative
  • You can add fragrance or essential oil at 2%. Many fragrances and essential oils can cause a reaction when you add them, making them cloudy or/and most commonly making the soap thicker or thinner. It may be an idea to remove a small amount of the soap for a trial run.
    For colors I find liquid soap color is the best to use as mica seems to fade over time. Add a drop at a time until you reach the desired color.
    Essential Oil or Fragrance Oil, Liquid Soap Dye
    Now we can divide into smaller batches, adding liquid soap dye and fragrance/essential oils as needed
  • It is a good idea to keep a cup of distilled water (room temp is fine) to add to the soap if it becomes too thick.
    If it becomes too thin, which is common when using citrus essential oils, it can be thickened with salt that’s been dissolved in hot distilled water. I work with 20% salt and 80% water, adding it a bit at a time until I’m happy with the consistency.
    bottles of lush smelling totally natural liquid soap


Shelf Life: Without a preservative, your liquid soap will last around 6 months. using one will extend the self-life to 18 months.
The recipe shows almost 2 days to make this soap, but remember that most of the time is not really active, it is spent waiting for the processes to complete.
Stage 1: Making The Soap Paste 
The soap paste in this recipe will take around 6 hours to cook depending on the heat setting on your crockpot. 
Stage 2: Dilution  Stage
The dilution time usually takes around 24 hours, you don’t need to do anything to it during in this stage, however, it’s almost impossible not to give it a quick stir now and again.   
Category: Soapmaking
Cuisine: N/A
Difficulty: Intermediate

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Final Thoughts

There we have it, natural liquid soap making that produces a wonderful product that’s both colorful and smells gorgeous. While this is quite basic, it’s important to get the techniques right before you waste money on more expensive ingredients.

One thing I really like about this recipe is just how much soap you can get from your paste. Each bottle can have its own unique fragrance and color and really gives you the opportunity to play around with fragrance combinations and scent profiles. You can pop leftover paste in the fridge to use later on, too!

I like to think of making liquid soap as one of the 3 pillars of diy soapmaking, along with hot and cold process methods. Mastering all three gives you so many options for you to play around with. You really can get creative!

So have look at some of my cold process recipes, as well as my hot process recipes too so you can get good at all three. Once you do that then the next step is to formulate your own recipes using the SavvyHomemade soap calculator.

You won’t regret it when your home is filled with the aroma of beautiful essential and fragrance oils. You’ll impress your friends, too.

Discussion (21 Comments)

  1. Hi! Thank you for the recipe; very nice! Do you know if replacing the olive with pomace olive will give the same end results in relation to the feeling on the skin and the cleansing?

  2. Hello! ????

    I think I would like to try this, with a twist.. I’ll try to cook it in a pot on the stove. I have done that before, but I don’t know if it will work with every recipe… I also am thinking of using sweet Almond oil instead of the olive oil… I have just bought a big bottle and want to try it.

    I just wish it was easier to find information if how oils will react in liquid soaps since it can be very different from a soap bar.

    A pure coconut oil liquid soap makes runny soap and olive oil makes a hard paste, I have heard from an experienced soap maker.

    Do you know where to learn about thing like that?

    Thank you!

    • Your best bet is to run your amended recipe through a soap calculator. Soap recipes are not very forgiving, especially when you change the ingredients. This is because all ingredients have different SAP values. This is the main problem we have when substituting ingredients like carrier oils, and if you don’t run your subs through a calculator there’s a good chance your soap won’t SAP properly.

  3. Hi Angela
    i make my own herbal shampoo using cold process method
    now i wnt to sell d product
    will u suggest a good preservative for my product

    • Hi There,

      As you’re planning to sell your liquid soaps it probably would be a good idea to add one. I would go for Saliguard PCG/Plantaserve P. You will need something with a very high PH tolerance range, and this one is pretty good for that.

    • Hi Kelly,

      I would just use distilled water. It’s the best thing to use for soap making as it’s pretty standard and easy to get hold of worldwide.

  4. Hello,

    Thank you so much for the recipe. I have one quick question, you said you like to work 1 to 2, if you have 700g of paste use 1400g of water but then it said to measure out the paste and then use that same amount of warm water. Do I double the amount of water?

    Thank you!

    • Hi Angel, thanks for pointing this out, I will alter the post to make it clearer, it’s a bit weird… But yes you double the water. That’s the best place to start, then you can add more water if it’s too thick.

  5. Hi, Angela. Thanks a lot for this Blog. Injust have one question. May I know what is the preservative I should use in liquid soap making?5 stars

    • Hi there,

      I like to use Plantaserve P/Saliguard. Essentially you are looking for a preservative that has a high PH tolerance but is also broad spectrum.

    • Hi Alexis,

      I just use food colouring which I just order from amazon. They come in a variety of colours and are great value for money.


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