Perfect for those with sensitive skin, this homemade glycerin soap recipe makes a hard bar of soap that lathers nicely while gently cleansing and moisturizing your skin.
What is glycerin soap?
It sounds like an easy question, but there is really a bit of confusion about what should be called glycerin soap.
When most people think of glycerin soap, they think of translucent soaps. Many think of the translucent melt and pour soaps that can be melted down to make easy, customizable soaps. (Although not all melt and pour soaps are translucent, of course).
What most people don’t know is that there is glycerin in all soap because it is a byproduct of the soap making process.
The difference between translucent “glycerin” soaps and other more opaque soaps with glycerin in them, is that the glycerin soaps have been cooked with certain solvents like sugar, alcohol, and, well, more glycerin, to help make the soap crystals small so that light can pass through. (It’s the soap crystals that reflect light back at our eyes, making soap opaque).
Glycerin soap benefits
Glycerin is a humectant, meaning that it helps retain, or reduce the loss of, moisture.
What’s special about glycerin, though, compared to some other humectants, is that it is an endogenous humectant, meaning we have it naturally in our skin. Glycerin has been shown to help restore moisture and elasticity in the stratum corneum layer of our skin, helping to restore the barrier that protects us.
Interestingly enough, even after you stop using glycerin topically, it can continue to help form a barrier to help prevent moisture loss for up to 2 weeks.
Glycerin soaps are thought to be milder and gentler on the skin. While that probably depends on each particular recipe or soap, I’ve found that this soap has worked well on my son who has sensitive skin with atopic dermatitis. (That said, I still use soaps, or other washing products like gels, sparingly on his skin, and most days only rinse the majority of his skin with water.)
I find this to be a great overall soap for face and body, and I like how it helps reduce acne on my skin.
Watch how I make glycerin soap
The Glycerin Soap Making Process
Making a translucent glycerin soap is really a two part process.
First, you have to make the soap, using a hot process method. (I use my slow cooker which works perfectly for both parts of the process.)
After you have made your soap, you need to dissolve the soap crystals to help allow the light to pass through the soap, making it translucent. To do that, you will use a combination of several different “solvents.”
On my first two attempts, I didn’t spend a lot of time trying to dissolve the crystals. I wasn’t careful to keep the slow cooker well sealed, and I didn’t leave the solvents to work longer, or add more of them, to try to get a more translucent soap.
If getting a more translucent soap is important to you, I’ve given you a range of different solvent values for you to experiment with. I chose to add an amount somewhere in the middle of the given range of each particular solvent. You may want to try adding a smaller amount, and increase, as needed, until your soap gets more translucent. Using a stronger alcohol will also probably help you get a clearer soap.
If you’re really picky about getting translucent soap, I’d suggest reading the book, Making Transparent Soap: The Art Of Crafting, Molding, Scenting & Coloring by Catherine Failor. Her techniques are the ones that most people follow when making both translucent solid soaps and translucent liquid soaps. She has another book about Making Natural Liquid Soaps. If you’re interested in making liquid soaps, I have a couple of liquid soap recipes up on the blog. (You can choose to make a liquid castile soap, or a liquid coconut oil soap, or make both and combine them to get the best of both worlds.)
Choosing oils for a glycerin soap recipe
Because we are going to be using solvents to dissolve some of the soap crystals, it’s best to use oils that make a harder bar of soap. This will help ensure you’ll still end up with a hard, long lasting bar of soap despite the solvent process.
In general, oils that are solid at room temperature tend to make harder bars of soap. (Olive oil can also make a hard bar of soap, but it usually requires a long curing process to get it to harden.) Tallow and coconut oil are great oils for this type of recipe; not only because they make a nice hard bar of soap, but they are also said to be good for making a translucent, rather than cloudy, glycerin soap.
Castor oil is another common oil used in translucent soap making, not because it’s a solid oil that makes a hard bar of soap (because it isn’t, of course), but because castor oil is said to be somewhat of a solvent on its own.
Even after using the solvents, this recipe made very hard bars of soap, and I really love the way it lathers. The coconut oil adds to the cleaning factor of the soap and helps make a bubbly lather. The castor oil helps stabilize that lather. This was the first time I used tallow for making soap because it’s not very easy to find here. (I wanted to make my own, but couldn’t get any butchers to save beef fat for me for rendering tallow.) I have to say that I really love it, and plan on using it more often.
Choosing an alcohol as a solvent
I would have loved to use a consumable alcohol without any added scents or ingredients like Everclear, but I wasn’t able to find anything like that here.
Funny story…
I actually went to the supermarket with my mother-in-law and bought some 70% absinthe because it was the only drinkable alcohol I could find over 50% here in Spain. I was slightly embarrassed buying it, and felt the need to say that it was for making soap. In the end, I felt bad about using an expensive alcohol in my experiments with making a translucent soap, and wasn’t sure how the green coloring would affect the color of my final soap. (I wanted to see what I’d end up with without adding anything at all to it.)
I decided to use some 70% denatured alcohol instead. I was worried about it leaving an unusual scent to my soap, but honestly I don’t notice any off putting fragrances from the alcohol, despite my having forgotten to add any essential oils in the end for fragrance.
I think next time I’d try with a stronger alcohol to see if my soap turns out more translucent. If anybody gives a 96% alcohol, or something similar, a try, I’d love to hear how it goes!
I now have been left with a completely full bottle of absinthe at my house, if anybody wants to come for a party. (Just kidding about the second part.)
Superfatting glycerin soaps
Because excess oils can make for a cloudy soap, I chose not to superfat this soap. (Superfatting is when you add more oils to the soap than what are needed to react with the amount of lye used. Some unreacted oils remain in the soap, and can leave a hydrating film on your skin when you use the soap.)
The excess glycerin in this soap helps compensate and acts as the leftover emollient that helps make a moisturizing soap. I used the same thought process when making my liquid castile soap and liquid coconut oil soap, and find that both are very mild for use on face and body.
Now that I’ve been using this glycerin soap for awhile, I definitely don’t think it’s missing anything, and love it just the way it is. That said, you could always try adding slightly more oil if you prefer to superfat the soap.
Glycerin soap recipe
Homemade Glycerin Soap Recipe (From Scratch)
Makes around 8 bars of soap.
Materials
For the soap
- 304 g distilled water
- 117.7 g lye NaOH
- 440 g tallow
- 200 g castor oil
- 160 g coconut oil
Solvents
- 120 g glycerin Between 98g and 147g
- 300 g 70º alcohol Between 275g and 321g
- 90 g sugar Between 73g and 110g
- 180 g distilled water Between 147g and 244g
Instructions
Make the soap.
- Weigh out the lye in a small, non-metal bowl.
- Weigh out the distilled water in another, larger, non metal bowl.
- In a well ventilated area, carefully pout the lye into the container with the distilled water. You should wear gloves and goggles to protect your eyes and hands. Stir the lye into the water until it is dissolved. The mixture will heat up and get cloudy at first, but will clear up and cool down with time.
- Leave the lye mixture to cool while you weigh out the oils. I find that the easiest way is to place the bowl on a digital scale, tare it, add an oil to the bowl until you reach the right weight. You then tare again before carefully adding the next oil, and between each addition.
- Add the oils to a slow cooker on low heat, and stir them together well. Allow any solid oils like the tallow to melt.
- Carefully add the lye mixture to the melted oils, and gently stir them together. Once the lye solution is fully incorporated into the oils, you can begin to blend them together with an immersion blender.
- Blend with the immersion blender until the mixture thickens to trace. Once the mixture has reached trace, place the lid on the slow cooker and allow the soap mixture to cook for several hours (around 3) until it starts to get transparent.
- You have now made a hot process soap.
Use the solvents to make it translucent.
- Weigh out the alcohol and the glycerin. You will be mixing them together and adding them to your soap. I would have liked to use a high proof alcohol like Everclear, but couldn’t find anything like that here in Spain. I ended up using a 70º denatured alcohol. they say that if you use a higher concentration of alcohol, that it will do a better job of making the soap more transparent. (Perhaps next time I’ll try with a 90+% denatured alcohol. Rubbing alcohol is said to leave an unpleasant scent behind, but I haven’t tried it to verify the difference.)
- Pour the alcohol and glycerin mixture into the soap. You’ll probably end up with chunks of soap floating in the liquid. Try to break them up as best as you can. (I used my immersion blender to break up the chunks and fully incorporate the alcohol and glycerin into the soap. Work in a well-ventilated area for this step and be careful not to have any open flames in the area. (You should always be careful when heating high percentages of alcohol.)
- Cover the crock pot, sealing it as best you can so that the alcohol doesn’t evaporate. (If it evaporates too quickly, it won’t be able to work its magic on the soap.)
If you really have your heart set on making a translucent soap, you should seal your crock pot with some sort of plastic wrap before placing the lid on top. I didn’t have any on hand, and wasn’t really too concerned about making a fully transparent soap, so I just used the regular lid of my crock pot. - Allow the soap to cook, covered and sealed, for around 30 minutes.
- Meanwhile, make your sugar syrup. Weigh out the sugar and water and mix them together in a saucepan over low to medium heat until the sugar has completely dissolved. Remove it from the heat.
- Once the 30 minutes has passed, you can begin to add the sugar solution to the soap. Gently mix it in, trying not to move the soap too much so as not to form a lot of foam or bubbles.
- At this point, you can begin to test the soap for translucence. It will look translucent to the eye, but as it cools, it will become more opaque. The way most people check is by freezing a glass, and adding a small amount of soap to the bottom of the glass to cool it. Keep in mind that you are using a very thin layer of soap, and that when you have a thicker layer it won’t be as translucent.
- To try to get a more translucent soap, you can continue to cook the soap, adding in small amounts of the various solvents and checking the translucence with the frozen glass. (To be honest, I didn’t bother, and just added the sugar, and went right to pouring the soap into the mold. Perhaps next time I’ll try for a more translucent soap, and will give you my tips for what works best.)
- At this point, you can add in any fragrances or colorings. The nice thing about this soap is that because it has been cooking for so long, and has completed the saponification (soap making) phase, you can even use food coloring to color your soaps. You won’t have to worry about the lye reacting with the colorants and changing them as often happens when adding things to cold process soaps.
- Clear the foam off the soap, and carefully pour the soap into your soap molds. Try to be gentle at this stage as any movement can cause foaming of the soap, which will lead to a more opaque soap. (I wasn’t very careful, and my soaps have a more transparent layer on the bottom, with a thin layer that is more opaque at the top, where the bubbly soap settled before hardening.)
- You can skim the foam off and pour it into small soap molds. They will make a more opaque soap that will work just as well as the rest of the soap.
- Allow the soap to set undisturbed overnight.
- The next morning, check the soap for hardness. If it is hard enough, unmold the soap and cut it into bars as needed.
- Allow your soap to cure and dry for several weeks. This is best done by separating the soaps to allow for air flow over them. It’s a good idea to rotate the soaps occasionally so that all sides dry at the same rate. The curing process will allow it to harden and finish any remaining chemical processes to make for a better soap.
My first experience making glycerin soap
The first time I tried to make a glycerin soap, I decided to try using a new wooden soap mold for my newly made soap. I should have experimented with a soap that was easier and quicker to make like my easy, beginner soap.
What happened?
The mold began to leak, and I ended up with my soap solution all over the counter. I scraped up some of it, and tried pouring it into another mold, but by that point I had a lot of parts that were hardening up and floating in the melted soap mixture. I decided that I was going to use my immersion blender to smooth out the mixture before pouring it back into the other mold.
The result?
Because I didn’t let the mixture settle again, I ended up with a more cloudy soap. The soap started to settle on its own leaving a clearer, harder bar of soap on the bottom, and a foamier, opaque soap on top.
What did I learn?
It’s just as important to be careful how you handle the soap when pouring into the molds. You want to be gentle and not incorporate a lot of air into the mixture. That is, unless you are going for this lemon merengue pie look to your soap! (I have to admit that it is kind of cool. The foamy layer is very soft, and almost like a marshmallow.)
Making a loofah soap
I decided to use the translucency of this soap to my advantage, and made loofah soaps. The loofah serves as a gentle, natural exfoliant for bathing.
To make a loofah soap, you can use PVC piping as your soap mold. If you have a PVC pipe cap, you can seal off one end with one of those. If not, you can seal off the end with some heavy plastic and rubber bands.
Add the loofah to the pvc pipe and weigh it down with something. (I used a spoon.)
Once in place, gently pour the soap into the pipe over the loofah.
When the soap has hardened, the easiest way to pull the soap from the mold is to put the pipe into the freezer for at least half an hour. Not only will this help solidify the soap, but it will slightly reduce its size long enough to help you push the soap out of the mold.
Carefully cut the soap into round bars and allow them to cure like you would any other bar of soap.
I’m sure somebody will ask me why the loofah soaps stayed white, while the other soaps turned yellow after during the curing process…
I wish I had an answer. I will say that they were from the same batch, and I didn’t add any colorants or any different ingredients to one versus the other. I poured the bar soaps first, and then filled up the pvc mold for the loofah soaps. If anybody has any ideas about why they aren’t the same color, I’d love to hear them!
jedearmon
BTW….I did make glycerin soap with pig tallow and it turned out really nice. It has an odd smell to it, but it cures out after a few weeks.
Tracy Ariza
Thanks for commenting on your experience. I’ll have to try sometime. I made a vegan version a week or two ago with mostly coconut oil. I’m waiting to let it cure further before taking pictures and posting about it on the blog. (A lot of people were asking for one that didn’t use animal fats.)
Did it turn out translucent? (Or weren’t you trying much for that? I never really care about it, but so many people ask me about these things.)
jedearmon
Thank you, Tracy…this was really helpful, and I enjoyed the video!
Tracy Ariza
You’re very welcome!
Rao Iqbal
Hi Tracy can you suggest any material to replace alcohal in soap as Muslims and Jews don’t use alcohal products please reply on my email can we try sugar can ferlmentedl solution or any other organic fermented solution to replace alcohal as viniger
Tracy Ariza
Hello Rao,
Alcohol is really the best solvent for dissolving away some of the crystalline structure to make a more translucent soap. You can still make the soap without it, but it won’t get that translucent quality.
It’s said that you can use propylene glycol, but I’ve never tried it. Some people have bad reactions to propylene glycol and I prefer to go a more natural route. Of course, if we must get technical, propylene glycol also has alcohol groups on the molecule.
From what I understand, though, you can get non-edible alcohol in pharmacies even in strict countries like Saudi Arabia. Of course, if you don’t personally feel comfortable using it, I understand and respect that, but it is something to consider.
Robin
Hello Rao,
I don’t know where you learned that Jews don’t use alcohol, but that is not true. I am sitting here waiting for my soap to cook as we speak, using Everclear (190 proof).
Best of luck….
VIMAL PATOLAWALA
Can we make clear transparent soap by altering the formulation little bit?
Tracy Ariza
I’ve been finding that by increasing the amount of the solvents used, I’ve had better luck getting it more transparent, but I still haven’t been successful getting it completely transparent, and it definitely doesn’t stay clear for me. In fact, the soaps I made here have darkened to an amber color with time. I need to take pictures and update the post to show them. They look pretty much identical to the glycerin soaps normally sold here in Spain.
I recently made a vegan batch with mostly coconut oil and the color was clearer. I’ll have to check on the color again to see if it’s stayed that way. I put them up high to let them cure and haven’t looked at them for the last couple of weeks. I haven’t been as concerned with the transparency so I haven’t put that much effort into that, but I think if you play with the amounts of solvents, you should be able to get closer to transparent soap.
chandra sekhar
Thank you friend . Its simple and super
Tracy Ariza
You’re very welcome!
QueenGold Ekanem
What is tallow?
Tracy Ariza
Tallow is rendered beef fat. That basically means that you melt beef fat and strain it and end up with a clean, white fat. It’s the equivalent of lard being rendered pork fat. (You can see the process of rendering lard here.)
Some places sell already rendered tallow to use for soap making which is what I used.
Chris
This looks great! Can I substitute the tallow with a vegan alternative (that is also not palm)?
Tracy Ariza
Hi Chris,
I’ve been getting a lot of requests for a vegan version, so I’ve been meaning to give it a shot.
The reason tallow is used is that solvents are being added to make the soap more translucent, and that can soften the soap. Animal oils make for a very hard bar of soap.
I just calculated out a recipe for using only coconut oil and castor oil, but I’d like to test it out before recommending it. 🙂
Perhaps I’ll give it a shot this afternoon.
VIMAL+PATOLAWALA
You may use rice bran oil and stearic acid in a ratio of 85:15.
Brenda
Everclear is not sold in my state…will the 91% rubbing alcohol work in it’s place? I am a new soaper…
Tracy Ariza
Hi Brenda,
I can’t find Everclear here in Spain either. I ended up using a 70% denatured alcohol.
I’ve heard it can be done with rubbing alcohol, but that it can leave behind an unpleasant fragrance. I think it depends a lot on the alcohol you’re using, and what’s been mixed with it to make it inedible.
I didn’t find my soap to have an unpleasant fragrance, despite not using any fragrance oils with it. I do notice a slight bit of a different type fragrance that may have come from the alcohol, though.
I’m planning on trying with a stronger alcohol and only vegan oils, and hope to post my new findings once I do.
VIMAL+PATOLAWALA
You can use propyl alcohol in place of rubbing alcohol. There will be slight smell in the beginning but will ultimately evaporate and fragrance will come out in pure form after drying period.
Tracy Ariza
Thanks! I’m glad to hear it!
nabil
Hi tracy
I have tried this formula and worked fine with this;
Coco oil 143g
Castor oil 93g
Stearic acid 63g
Lye 47g
114g distilled water
86g glecirine
140g Alcohol (90%)
Sugar 36g and water 35g
The result was more clear then yours
I am asking if I can use 96% alcohol. But how much will be the quantity???
Tracy Ariza
Hi Nabil,
Great to hear that! I want to try making a vegan version myself as many people have asked me for one without tallow. Does it make a hard bar of soap?
What alcohol did you use for the batch that you already made?
I think you can use higher percentages of alcohol, and, in fact, I think it’s supposed to be even better, but I think you are supposed to reduce the amount of alcohol slightly. I’m not really sure by how much, though. It’s been awhile since I researched making this type of soap.
Faraz A.
Awesome. I’ll try and make my own soap.
Tracy Ariza
Great!
I hope you enjoy making and using it!
MYRA
Hi! WHat can I use instead of tallow? Any other oil?
Tracy Ariza
Hi Myra,
I’m working on it–
I plan on trying to make a vegan version with only coconut oil. I’m just waiting for my husband to buy a new type of grain alcohol to try using it as a solvent too.
For now, the reason for the tallow is because it makes a nice hard bar of soap that stays hard even after using the solvents.
Bright Ejegi
thank you very much for that recipe I will work on it
Tracy Ariza
You’re very welcome! 🙂