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When making liquid soap using the soap paste method, you’ll need to dilute it to use it. Learn how simple it is to dilute a liquid soap paste, and how you can customize it during the process.
Over the years, I’ve made many liquid soaps using what is called the liquid soap paste method. In the liquid soap paste method, you make a thick, putty-like, pliable paste that needs to be diluted in water to use as a liquid soap.
On the blog, you can find a recipe for a liquid soap made with coconut oil, a pure Castile liquid soap made with only olive oil, and a combination liquid soap, Dr. Bronner’s copycat recipe.
For help deciding which one to make and more information about making liquid soap, check out my post on how to make a liquid soap (start here).
Benefits of the liquid soap paste method
I choose the liquid soap paste method because it’s easy and comfortable to use. The soap paste doesn’t take up a lot of room and stores very well. To save time, you can make large batches of liquid soap paste and safely store it away compactly for many months, (Or years!) only diluting the amount you’ll use relatively soon.
How to dilute a liquid soap paste
There are several ways to dilute the soap paste, depending on how quickly you need it. It can be as simple as just adding some distilled water to the paste and allowing it to dissolve into the water on its own, or you can speed up the process by using a bit of heat.
Using a slow cooker
A lot of people choose to dilute their liquid soap paste in a crock pot or slow cooker.
This is the method I use to dilute a fresh batch of liquid soap paste as it’s already in the crock pot anyway. I don’t like to dilute all of my paste at once, though, so I take a lot out and store the paste in glass jars with a wide mouth for easy removal later on.
(The more water something has, the more likely it will go bad more quickly, so I prefer to leave most of the soap in its paste form so that it will last.)
When using this method, I’m not very precise in my dilution rates. I usually eyeball the remaining amount of paste and pour in an “equal-ish” (yes, that’s the technical term, I think) amount of hot water. I then stir it all up as best as I can.
It’s important to add hot water if your soap paste and crock pot are still hot from making the soap paste or your crock pot can crack if you add even warm water to the hot paste mixture. (Don’t ask me how I know that.) 😉
You can then turn the crock pot off and leave it alone for several hours, or overnight. If you happen to walk by, consider stirring it to help it dissolve more quickly. In the end, though, if you aren’t in any hurry, just let it do its thing. It will dissolve on its own.
If by the next day the soap paste hasn’t dissolved, you can turn the heat to low for several hours or just let it sit for longer. If you still have big pieces of soap paste, you should probably add in a little more water and can also break them up to help dissolve them more quickly. Eventually, the soap paste will dissolve.
Of course, if you’re in a hurry, turn on the heat and stir the soap paste until it dissolves. It may get foamy at first, but it should clear as the foam goes away.
On the stove
As you can probably imagine, diluting the soap paste over the stove is very similar to the crock pot method. If you are in a hurry, you can cook the soap paste and water over low heat to help dissolve the soap paste. If you’re in less of a hurry, but want to get a head start on dissolving the soap paste, heat the water to almost boiling and then turn the heat off and add the soap paste. Stir it in as best you can and then allow it to rest until it dissolves.
Just as with the crock pot method, you can heat up the mixture again if, after several hours it hasn’t dissolved much and you want to help move things along more quickly. Or, you can just leave it be for as long as it needs.
Leave it alone method
Honestly, this is probably the method I use most. Take some soap paste, pull it apart into relatively small chunks and pour some distilled water over them in a jar. Cover the jar, and leave it alone for several hours/days.
If I happen to be near the soap jar and think about it, I may occasionally give it a shake or stir. Mostly, though, I just leave it alone and forget about it until I need it.
I think it’s impatience that frustrates most people when diluting their soap base, but if you give it enough time, and enough water, it will eventually dissolve on its own. That’s why I start diluting when I see that we are starting to run out of diluted soap, not when we’re already out!
Dilution rates
Many people have asked me how much water they should be adding to their soap paste to get a proper liquid soap. For me, it’s more of a personal preference.
While I don’t normally weigh out the ingredients to follow a particular dilution rate, I normally visually judge how much water and soap paste I’m using. It generally ends up being around 1 part of soap paste to 1-3 parts distilled water.
Thin soap
The more water you add, the thinner the soap will get. Just because your soap is on the thin side, though, doesn’t mean that you don’t have a decent soap. Without thickeners, liquid soap will seem thin, even while still pretty concentrated.
I used to only dilute my liquid soap enough to make it a thick, dense liquid like many commercial soaps. By doing so, though, I decided that I was just wasting a lot of soap.
You know those commercials for dishwashing detergent that try to convince you that their product is so powerful that you’ll use less and save money in the long run?
I always roll my eyes at those commercials because I think, “Even if people could wash their entire load of dishes with one drop of soap, nobody is going to do it!”
We get used to pumping out a certain amount of soap, no matter how thick it is or how cleansing the soap is. So, even if we use a thicker, more concentrated soap, that doesn’t mean we are going to use less of it.
As an experiment, I started diluting my soap quite a bit more, leaving it a thinner consistency, not unlike Dr. Bronner’s soap. I found that we ended up using a lot less overall. We didn’t feel less clean, but were using up the diluted soap at about the same rate as we were using the thicker, more concentrated soap.
Plus, when the weather got colder, my thicker liquid soaps got cloudier and more opaque at higher concentrations! If I wanted my soaps to be more clear and transparent in the winter, I was needing to dilute them further anyway.
When I finally got around to buying a bottle of Dr. Bronner’s liquid Castile soap, out of curiosity, I was surprised to find that theirs was pretty thin too, despite them stating that it is very concentrated. That showed me that the density of the soap doesn’t necessarily correlate with its concentration or cleaning power.
Dealing with thin soaps
Most commercial soaps use some sort of thickening agent to thicken them. While I’ve read that you can successfully thicken liquid soap with salt, I’ve never been successful at thickening my homemade liquid soaps with salt. (I do use salt to thicken my non-soap homemade laundry detergent.)
Some people use gums and other similar type thickeners to get a thicker soap. (That’s the method I use to thicken my clarifying shampoo.)
For easier usage of a thin liquid soap, I generally use a foaming dispenser rather than try to thicken it. A foaming dispenser will add air to the soap as it’s dispensed, giving a foam that is easy to apply. We also use regular pump dispensers in some areas of the house. While the soap still dispenses on the thinner side, it’s easier to dispense and use a proper amount that way.
Perhaps I’ll start experimenting again with the best ways to thicken liquid soap and will write a post dedicated to the subject.
Second dilution
Most people make one type of soap, dilute their soap to the consistency they like, and that’s that.
I, on the other hand, like to have some concentrated liquid soap ready for mixing and for a second dilution. My concentrated liquid soaps are generally made at a 1:1 concentration of soap paste to distilled water or thicker. (They may have even less water than that.)
Because different oils have different properties in soap making, you can combine several different types of liquid soap to obtain the benefits of each of them. When making bar soaps, you’d have to decide on your concentrations and make the whole batch the same way, but with liquid soaps, you can combine the already made soaps after the fact.
Soaps made with olive oil tend to be conditioning, but they don’t usually give off a lot of lather, and aren’t usually as cleansing as a soap made with coconut oil.
Soaps made with coconut oil tend to be very cleansing and they make a nice bubbly lather, but they can be drying on the skin.
For face and body uses, you could combine them, using more of the olive oil soap. For general cleaning around the house, you could use only coconut oil (or add a bit of olive oil soap if you’re cleaning something delicate like a leather sofa).
I’ve found it’s easiest to have two big jars of thick, yet diluted liquid soaps (one made with only olive oil and one of coconut oil soap) ready for mixing and further dilution.
When it’s time to refill a dispenser, you can fill the dispenser around half full with distilled water (or more or less, despending on how thick you want it), and fill the rest with either of the soaps, or a mixture of both.
Adding fragrances
During the dilution, or second dilution when using that method, it’s the best time to add in any essential oils or fragrance oils.
Liquid soap is great in that it doesn’t need as much fragrance to be noticeable. Many people choose to use essential oils to add fragrances to their soaps in a more natural way, but they are frustrated that they need to add large quantities for the scent to be noticeable.
While you can get away with using much less fragrance in liquid soaps, essential oils and other natural fragrances still last much less time. That’s why it’s best to add the fragrances right before you are going to use them. (In bar soaps, the fragrances have to survive the cure time before you’ll even be able to use your soaps.)
Cloudy liquid soaps
If you find that the soap becomes cloudy when you dilute it, don’t worry too much. It’s generally safe to use, but it’s normally more of a cosmetic issue.
Cloudiness can be due to a number of factors.
One of the most common reasons for cloudy liquid soap is that it has been made or diluted with tap water instead of distilled water. Tap water can include impurities and minerals that can change the appearance of liquid soap.
Depending on the oils used to make the liquid soap, or how many oils were used, a soap can also be more or less cloudy. (Some oils, like jojoba oil, have unsaponifiables that can cause cloudiness in liquid soap.) Most of the time liquid soap isn’t superfatted (or at least not by much) because superfatted liquid soaps can become cloudy or even separate.
The other common problem is that the soap paste may not have finished the saponification process (or may just need to be cooked a bit more). To check for safety, you can do a “zap test”. If the soap passes, you can use iteven if the soap is cloudy.
The zap test
To check for safety of the soap, many soap makers rely on what is called the zap test. To zap test a liquid soap paste, run your wet finger over the surface of the paste and then touch your soap-covered finger to your tongue. If the soap is caustic, it gives a zapping sensation. (This has nothing to do with flavor.)
If the soap doesn’t zap (if you can’t tell, it doesn’t), then it doesn’t have any more active lye, and should be safe to use.
May times, a cloudy liquid soap will clear on its own if allowed to rest for several hours/days. This is called “sequestering” the liquid soap. Often times solids will fall to the bottom or unsaponified oils will float to the top. You can then carefully remove the clear soap from the center if that happens. (Or you can leave it as-is if the cloudiness doesn’t bother you.)
For more information, read my post about troubleshooting liquid soap problems.
Homemade Liquid Coconut Oil Soap
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Thomas
Hi Tracy,
I love your blog. I followed your most basic Dr Bronner recipe (just coconut and olive oil) to make soap last week. Except, I halved the recipe, used a rice cooker (because of smaller volume), and accidentally added like an extra 5grams of coconut oil than your recipe by accident when I was measuring out everything.
The soap paste still came out okay, I think. However when I diluted it in distilled water, it was fine at first but has separated. The lighter top part still foams and cleans, so it’s not oily.
Just wondering if this has happened to you before, or whether you know what I have done wrong?
Thanks,
LThomas
Tracy Ariza, DDS
Hi Thomas,
That’s interesting and not something that has really happened to me. (I have had an oil separate out as a thin top layer, but nothing else.)
What do the various layers look like? Are they similar thicknesses?
Maybe, send a picture to tracy@thethingswellmake.com and I can make a better guess?
Sun
If I diluted my soap paste and now have liquid soap, do I need to add more water in order to add it to a foaming pump bottle or can I just add add diluted soap as is?
Tracy Ariza, DDS
Hi Sun,
Normally, diluted homemade soap is thin enough to be able to use in a foaming dispenser at most dilutions. On the other hand, foaming dispensers allow for adding more water and saving soap, so I generally dilute the ones that I plan on using in foaming dispensers slightly more than the ones I plan to use in other dispensers.
meister
Hi Tracy, great tutorial, I have a question for you. Do you find your liquid gel base getting more concentrated over time. For example, I was using about 2 to 2.2x water to gel base to dilute. But I’ve found out that if I leave the gel for more than a year before diluting, I use a lot more water to gel ratio. Have you found out that to be the case? Or am I doing something wrong? TIA
Tracy Ariza, DDS
Hi Meister,
I haven’t noticed that, but it could be due to evaporation of the water from the soap paste, depending on how you have it stored.
If it isn’t sealed in an airtight container, the paste can dry out, so you need to add more water to hydrate it again.
Nasly Duarte
Thank you so much for this! I also make soap paste and always want to make sure that I’m keeping up with trends and my dilution is on point.
Johanna
Hi so I’m pretty new to soap making. I followed a basic tutorial from YouTube on how to turn bar soap into liquid soap. I got a bar soap (4-5oz) shredded it and then melted it down with about 10 cups of water. I don’t have any glycerin so I didn’t add any but the person I watched said it would fine still. I put the cooled mixture in some jars for about a day until it turned into a gel, hard jello like consistency. I blended it until smooth for a thick liquid.
My problem is that after a few days the soap has solidified into a slime. I put some into a soap pump and now its too thick to get through the pump. I don’t know if I can dilute it like you have here, if I should reblend it ir what I can do. Please help, much thanks.
Tracy Ariza, DDS
Hi Johanna,
The problem here is that you’re trying to turn bar soap into liquid soap. Bar soap is meant to be bar soap, and liquid soap is made with a different type of lye.
Yes, some people try that, and some like it and seem to be successful with it. (I’m not a fan of it. I make bar soap to be used in bars and liquid soap when I want liquid soap.) I only tried that once myself- hated it- and never did it again! (I’m sorry to be the bearer of bad news!)
Pris
Thank you for sharing. I was wondering if you have a substitute for hemp, I’m trying to stay away from that and lye.
Tracy Ariza, DDS
Hi Pris,
I have several liquid soap recipes on the blog that do not use hemp.
Unfortunately, it’s impossible to make soap without lye. (I have more information about that in my post about lye).
Leigh
Hi!
The second time I made castille soap in my crock pot, the crock pot cracked, pouring unprocessed lye and oils all over my floor! It was a disaster! I figured it had cracked the first time I made it, and I just didn’t notice, or alternatively that the lye was corrosive enough to crack the ceramic? Now I’m worried about making soap again, as I don’t want to break another crock-pot! If you have any tips on this, that would be greatly appreciated. Is it possible that the temperature of the oils is not right when adding the lye to make it crack? Or, is it more likely as you described above that the temperature of the water is not high enough when diluting the soap paste?
Thanks!
Tracy Ariza, DDS
Hi Leigh,
Wow! I’m sorry to hear that!
I’ve cracked several Crock Pots over the years, but it’s been when I’ve been cooking. They seem to be quite sensitive to changes in temperatures. I’ve added warm water to a hot one, thinking it will be fine because it’s not cold, but even the minor difference was enough to slowly crack mine. (I was able to use it for months cracked, though.)
I’m not sure why yours would have cracked, but I assume it’s more of something to do with temperature than with the composition of the lye solution. (I’ve made many, many batches in this new one without any issues.)
I would add the oils before turning on the Crock Pot. Don’t add cold oils to a hot Crock Pot. If you find that the lye solution is extremely hot- try to add it when it’s a similar temperature to what is in the Crock Pot. I hope that helps.
Prossy
Can i use palm oil to make Castile soap?
Tracy Ariza, DDS
Well, technically, it wouldn’t be Castile soap. Castile soap is made with olive oil. (Although, I guess some modern uses of the name do include other vegetable oils. It should still contain some olive oil, though, to be considered a Castile soap.)
You can make a liquid soap with palm oil, but I’ve never tried it, so I don’t know what the final product is like. You’d have to run it through a lye calculator (I explain how to use a lye calculator in this post.)
Denise Berger
I would LOVE to see a recipe for dishwashing soap. I have looked EVERYWHERE including here. I did make the liquid laundry detergent and have a gallon of “foam”, which I use and works ok, just weird how it all foamed up and stayed that way. I was thinking of modifying that recipe somewhat to use on my dishes, perhaps with some d-limonene which I happen to have. Any ideas?
Tracy Ariza, DDS
Hi Denise,
For hand washing, I successfully use both my liquid Castile soaps and/or the laundry detergent- as you tried.
Neither have worked for me for a dishwasher, though. (They seem to at first, but then leave a buildup.)
That said, I’ve been successfully using a dishwasher powder for several weeks now. I think I mixed sodium percarbonate, washing soda, and some powdered surfactant. I can’t remember what I ended up using exactly, though- and have to find where I wrote down the recipe. I’m really happy with how it works, though, so I do plan on posting as soon as I can. 😉
Bles
Hi Tracy,
My husband is quite particular regarding the type of soap he uses, especially with hand wash. Apart from doing a 1:1 ratio to make the soap thick, can you recommend a thickener I can use? Maybe xanthan gum?
Thank you,
Bles
Tracy Ariza
Hi Bles,
I’ve read it works, but haven’t personally tried it. I guess I should give it a shot so I can give a more confident answer. I’ve tried thickening with salt (because I’d read it also thickens soap), but wasn’t successful with that with my soaps. (It does work as a thickener in my homemade laundry detergent, but that isn’t soap-based.)
I usually add mine to a foaming dispenser- which is why I don’t worry about thickening.
I do thicken my shampoo with xanthan. I was going to make a batch tomorrow, so maybe while I’m at it, I can give it a try for my liquid soaps.
Micaiah
Hi Tracy,
I’ve been making homemade soap following your recipe and have been adding some guar gum to thicken the diluted soap. I’ve found that it leaves my hands feeling really dry and almost sticky while washing. Any ideas on how to fix the texture?
Thank you!
Tracy Ariza, DDS
The texture could be from the guar gum. Does it feel sticky to you if you don’t thicken it?
I need to find a good way to try to thicken soaps. I usually use them in foam dispensers, though, so I leave them on the thin side.
Dizzy
Hi Tracy & Bles,
If you want to thicken your liquid soap you can do so with the cheapest table salt from any supermarket, not fancy salts, just bog standard fine table salt.
Once you have your diluted soap make a salt solution (15g of salt added to 43g warm distilled water and stir until the salt is fully dissolved). If you’re adding EO’s to your soap and haven’t done it then do it before adding the salt solution as some EO’s will thicken the soap, just as they can make it seize at trace.
Add 1ml at a time of the cooled solution to your soap and stir, wait and check consistency, add 1ml at a time, if you add too much at once within half an hour you can have soap jelly, or worse a yucky over diluted runny soap that doesn’t foam (think of over whipped cream and how it starts to separate). ?
Hope this helps ? I’m not a fan of xanthan gum in soap, I don’t like the feel it gives it.
Marianne
Hi! I was wondering what to do when my soap paste isn’t diluting into the water. Do I need to add more water?
Tracy Ariza
Hi Marianne,
I’ve never had that issue, but I pretty much always use glycerin in liquid soap recipes and I’ve read that it really helps to make the soap easily dilutable.
I would first try using heat to help dilute the soap with the amount of water you’ve added. If heat doesn’t work, then I guess adding more water would be the next step to try.
Leave the soap paste with water for as long as it is needed. If you have a stubborn soap paste, that may mean you need to leave it for days in water. Ideally, you’ll want to shake or stir it as often as you remember, until it dissolves completely.