Getting Ready to Make Liquid Soap


I’m studying on liquid soap. I always have to study on something new for awhile before I take the plunge. Study is possibly another word for procrastination, but even if you’ve made “regular” hard soap, liquid soapmaking is a little bit different, just different enough to require some study.

What goes into liquid soap? Liquid soap, like any soap, is created by combining fat with lye. The fat can be all sorts of things–-but for liquid soap, as opposed to hard soap, coconut oil (for lathering) in combination with soft oils is recommended. Soft oils are generally oils that are liquid at room temperature (such as olive oil).

The lye used in hard soap is sodium hydroxide, otherwise known as caustic soda. Liquid soap requires a different type of lye–potassium hydroxide (caustic potash). Potassium hydroxide is more soluble than sodium hydroxide, which makes liquid soap possible. The same safety precautions remain–use goggles and gloves when handling potassium hydroxide, avoid inhaling fumes, and store securely out of reach of children and pets.

You don’t have to learn how to make hard soap before learning to make liquid soap, but if you’ve already tried your hand at hard soap, you’ll find some of the procedures in liquid soap to be comfortingly familiar. I’m going to be making liquid soap by the hot-process method. You can use a crock pot, a double boiler or even the oven. Liquid soap starts with melting the fats/oils then combining the lye and water. (Use soft or distilled water. The minerals in hard water cause cloudiness in liquid soap–so while you may get away with that in hard soap without notice, it will hurt the look of your liquid soap.)

There are two distinct methods for making liquid soap, both of which diverge from the process of making hard soap after the first few steps. The “paste” method is much more similar to making hard soap. In the paste method, you use a stick blender to stir to trace then cook the soap to a paste before proceeding with dilution. In the “alcohol” method you add ethanol or isopropyl alcohol to the liquid soap mixture immediately after adding the lye/water mixture to the fats/oils and rather than stirring with a stick blender to trace, you stir until you have a homogenous mixture then cook a sort of soap “soup” on a continuous boil.

In either method, the soap is diluted with more soft or distilled water after it finishes cooking. The alcohol method has the advantage of being more easily diluted and producing a clearer soap. (The alcohol can be evaporated out of the soap, by the way.) The alcohol method also doesn’t require the stick blending to trace, so it’s a little easier that way, too, but you have to wrap the top of your pot with thick plastic held on by bungee cords, so it’s a little more like a mad scientist project.

Because it’s so important that all the fatty acids in clear liquid soap are saponified (to avoid cloudiness or separation), many soapmakers formulate their recipes with a lye excess. Potassium hydroxide flakes intrinsically contain water and other impurities, up to 10 to 12 percent, which means the lye excess in liquid soap recipes is not as high as it initially appears. Even so, liquid soap made this way must be further neutralized to get rid of the excess and lower the pH. This is done by adding a solution of boric acid, borax, or citric acid after diluting the soap (in either the paste or alcohol method). Until you are experienced enough to formulate your own recipes, it’s a good idea to use recipes from expert sources. I’m using the book Making Natural Liquid Soaps by Catherine Failor, among other resources.

After neutralizing the diluted soap, you can add dyes and fragrances then the liquid soap is “sequestered” for one to two weeks, meaning it’s allowed to sit undisturbed to settle. (Actually, you could safely use it right away, but allowing the soap a “rest time” will add brightness and clarity.)

Today, liquid soap tends to be much more popular than hard soap. While I love the look and feel of old-time hard soap bars made in a plain mold and cut in thick slices (wow, what looks more awesome than that?), in practical terms, many of us want the convenience of a liquid soap. Morgan, in fact, refuses to use the hard bars I make. She prefers liquid soap. I know that many of the people I give gift bars to also prefer liquid soap. I want to learn to make liquid hand soap, shower gels, and shampoos. And so, while hard bars have their place, there is a lot of room for liquid soap, too. It’s the next step in my soap journey.

Who’s coming with me?

Here’s a list of things to gather if you’re going to get ready to make liquid soap. If you’ve made hard soap before, you probably already have most of what you need.

*Your choice of fats/oils (most likely, coconut oil plus soft oils)
*Potassium hydroxide
*Soft/distilled water
*Citric acid, boric acid, or borax
*Your choice of dyes/fragrances (optional)
*Stick blender and large stainless steel spoons
*Large stainless steel or unchipped enamel pot or unchipped enamel crock pot
*Scale, thermometer, bottles and jars

You can find potassium hydroxide on the internet at soapmaking suppliers, along with various fats/oils (some of which can also be found at the grocery store), and dyes and fragrances. You can find borax at the grocery store. You can find citric acid at some grocery and health food stores or online at various types of suppliers. If shopping online, just do a search on the ingredients you’re looking for. A couple of suppliers I use are Wellington Fragrance and Bramble Berry. You can get potassium hydroxide at Bramble Berry. I prefer Wellington for essential oils, etc.

Get ready! I’m laying in the supplies and will be posting my adventures soon. Liquid soap, here we come!

P.S. You can also make liquid soap with milk, and I’ll be trying that, too. Gels, by the way, are a slightly different process, and will be another adventure. There’s more than one way to make a gel, one being the inclusion of alcohol and glycerin. (Another method, for gel recipes with high proportions of soft oils, is borax.) Liquid soapmaking includes many mini-adventures within it.

Want to try hard soap first before taking the liquid soap plunge? See all my soapmaking posts here for my hard soap tutorials.


  1. Rachel says:

    I am so excited about this adventure you’re about to start! I’ve been wanting to try my hand at liquid soap for quite a while now. I even got the Natural Soapmaking book you mentioned from the library and read over it, but I never got around to actually making to soap. Maybe you’re adventure will be the inspiration I need to start my own!

  2. Deb says:

    How strange, I’ve been thinking I would like to learn to make some too…just haven’t got to the point of researching it yet (which I do a lot to, before actually doing it). I’ll enjoy reading about you making it, as it will give me some ideas for when I get around to doing mine. 🙂

  3. Susan says:

    Wow – you did all the work, now let’s get started!

  4. Ruth C says:

    In your research, did you find anything on how to make the watery-liquid soap that can be used in the dispensers that make soap foam? I’d like to not have to keep getting refills of that and make it myself!

  5. Ramona says:

    I haven’t heard of part of that stuff on your list.

  6. Ruth C says:

    I think I’ll try it! I’ve been making your laundry soap and love it. Thank you!

  7. Jblank says:

    I often wonder how much a lot of these projects cost you to start. It might be helpful if you gave the readers an idea so that we know how it might fit in our budgets if we wanted to try.

    • Suzanne McMinn says:

      Jblank, the cost of fragrance or essential oils varies (and they’re optional–fragrance oils are less expensive). You can check out various fragrance and essential oils at Wellington or Bramble Berry. The potassium hydroxide is $10/pound at Bramble Berry. Coconut oil is $18.95 for a gallon from Wellington (this goes a LONG way and will make a lot of soap!). For other fats/oils, you can use what you can buy at the grocery store, such as olive oil. The other necessary items–pots, utensils, kitchen scale, etc, are usually things you have on hand in your kitchen.

  8. B. Ruth says:

    Ruth C.
    I got for a gift..some foam soap I loved…when I went to buy it all they had left was non-foam…bought it…I had saved my dispenser and put the regular soap in it…added some water…shook to mix and did a squirt foamy foamy…LOL
    So it is working for me…and the foam soap was the same price as the regular liguid soap…go figure…now I make my own foam just need the bottles…
    Suzanne…do you think making liguid laundry soap would be cheaper in the long run?…I am sure the chemicals would be safer but would like cheaper as well?

  9. iowacowgirl says:

    How nice of you to read my mind (not a great feat!!); this is exactly the tutorial I need. I employ home-made dishwasher detergent and HE laundry detergent…now for the liquid stuff….yay…I’m all eyes and ears.

  10. Mary Fran says:

    I have many bars of commercial soap that my children refuse to use. They prefer liquid hand soap and liquid shower soap. Rather than toss them out do you know how to melt these bars down to make your own liquid soap?

    In regards to how to turn store bought liquid soap into foam soap, place approximmately 1 TBSP of liquid hand soap in an empty foam soap dispenser and fill the rest of the dispenser with warm water.

  11. Kat says:

    I’m stoked! I’ve been making my own soap for a little over a year now, and I’m ready to move on to the liquid soap. Let’s do it!

  12. Amerayl says:

    :sun: How exciting! I love making soap of all sorts. Although I have only made liquid soap for making my dish soap so far. I like making cream soap to use as bodywash and shaving soap. I use the calculator at summer bee meadow as they have a more accurate cal for KOH. I haven’t used borax to neutralize make pastes as yet. But that may have been a fluke. I thought about use KOH for my laundry soap, but it is more $$$ than NaOH for me right now. But the idea of a non gloppy egg drop soup like laundry soap is very appealing.

  13. hawkswench says:

    Suzanne have you ever read the Foxfire series?

  14. Mandy says:

    I’ve been wanting to make homemade liquid soap for a few months too! I can’t wait to see your next posts!

  15. princessvanessa says:

    I don’t think “studying” is procrastinating. I have found that if I carefully think through the steps before starting a project I can often think of a better way of doing it. Or, I realize that I will need to take things slow….for safety’s sake. When I have rushed into something I often find that the results are less than perfect and I am dissatisfied with the end result.

  16. Sarah says:

    My idea of “studying” is saying “Oh that sounds like something I’d loooove to do” and then keep saying that over and over and over but never do it. I have a long list of things like that. Soap and cheese making are on that list. It’s ultraprocrastination. Someday, though, I will do it. And I’ll write a blog for all the other ultraprocrastinators!

    Now I’m going to be a super-nerd and correct you.. you say “isopropyl and ethanol alcohol” which is incorrect. If you say ethanol you’re implying that you’re using ethyl alcohol. When you say isopropanol you’re implying you’re using isopropyl alcohol. So saying ethanol alcohol is redundant.

  17. Mountain Blessings says:

    Suzanne, do you ever sleep??? I’m exhausted, you have cleaned out your fridge, your downstairs room, making list and making soap, not to mention the other million things you do a day :bugeyed: ! Where do you find all the time??

  18. Jessica Tibbetts says:

    OOO! I’m in. I’ll order potassium hydroxide next week and then get going! I have been “studying” how to make liquid soap from the same book for about five years now. It will be nice to have someone else doing this, too.

  19. Carmell says: has a pretty easy tutorial.

  20. mammaleigh says:

    OK I just got all of my stuff to do the hard soap…I want to do the liquid soap too!!! My family will smell so good…Thank you for everything that you teach us and research for us!

  21. Linda says:

    Thanks for sharing this….I have never made my own liquid soap….very interesting so I printed it off and I will give it a try.
    Have a Blessed Day!

  22. Spiderjohn says:

    Suzanne, do you really think you can save money making your own? I can buy a big bottle of liquid handsoap at Dollar General or one of those places for next to nothing!

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