I have written before about the many benefits of using salt, both internally and by transdermal application. A fun and easy way to incorporate some of these benefits into your daily routine is by adding salt to your homemade soap. Salt is an inexpensive additive that transforms a regular bar of soap into a luxurious sea salt soap bar that gently exfoliates and softens your skin.
If you are new to soapmaking, I would recommend reading my tutorial on how to make cold-process soap so you have a good grasp of how to make soap before you get started with this variation.
There are a few important things to understand about adding salt to soap that make it a bit different than traditional soapmaking. Let’s get started…
Adapt The Recipe
Your favorite soap recipe will need to be adapted before adding salt. When salt is added to soap it greatly reduces the lathering abilities of the average soap recipe. In order to counteract this effect, you will need to increase the amount of coconut oil to at least 70%.
Coconut oil makes large, fluffy bubbles so this high amount is able to give salt bars a nice lather, but it also can be very drying when used in large amounts. Typically, you would use somewhere between 15-50% with a 5-8% superfat.
Because this recipe will be using 70% coconut oil, I have increased the superfat to 15%. There is a bit of slip when I am rinsing the soap off but I have not found it to be excessive and this soap does not dry out my hands. You could definitely try a lower superfat percentage, just be sure to recalculate your recipe to find the correct amount of lye needed.
What Kind Of Salt to Use for Soap?
A better question is what kind of salt should you NOT use. Dead Sea salt and epsom salt are not advised. Dead Sea salt has a very high mineral content and epsom salt is high in magnesium. Both will draw moisture from the air and make a sweaty, weepy soap.
Sea salt and Pink Himalayan salt are both wonderful choices. The size of the salt grain is a matter of personal preference. I used a large grain but you can certainly use a fine grain if you prefer. The warm water dissolves the salt as you are washing so it is not rough or sharp on your skin.
How Much Sea Salt?
There is really no set rule regarding how much salt should be added. Anywhere between 50-100% of the amount of soaping oils can be used. For everyday hand-washing I like 50% because higher amounts can be slightly drying to your hands, but a higher salt percentage makes a great body bar for the shower.
This number is calculated by the weight of the oils alone, not the weight with the water and lye added in. So for example, if you want 100% of the oils you would use 32 oz of salt for 32 oz of oils.
Adding Salt and Molding
The salt is added after the lye/water has been mixed in and your soap has reached trace. Just pour it in and mix it with a spoon. The soap will set up fast once you add the salt so it is important to move fairly quickly. In fact, you will probably need to spoon the soap into the mold rather than pour it.
If you will be using a traditional log mold your salt bars need to be un-molded and cut about an hour or so after they are poured into the mold. This type of soap gets hard quite fast and if you wait too long you will end up crumbling the soap when you try to cut it.
Personally, I find it the easiest to use individual cavity silicone molds for this project. I leave them overnight and they just pop right out with no problems.
I have a set of supplies I keep on hand for making soap. You can use your kitchen tools if you are diligent about cleaning them thoroughly, but I prefer to keep them separate.
- Glass canning jar or high quality pitcher for mixing lye and water
- Second glass jar or disposable plastic cup for measuring lye
- Non-reactive pot or slow-cooker for warming oils
- Small glass bowl for measuring essential oils (optional)
- Digital infrared thermometer or 2 candy thermometers (one for lye and one for oils)
- Soap mold- (I used these tree molds in the picture)
- Immersion blender
- Digital scale
- Spoon for mixing lye
- Protective gloves and eyewear
- Vinegar for final clean-up
Sea Salt Soap Ingredients
All measurements are by weight. This recipe has a 15% superfat and makes 2 lbs of soap.
- 11 oz coconut oil
- 3 oz olive oil
- 1 oz castor oil
- 1 oz mango butter
- 8 oz Himalayan sea salt (or natural salt of choice)
- 6 oz distilled water
- 2.3 oz lye
- .5 oz lavender essential oil (optional)
Sea Salt Soap Instructions
- Prepare your mold. If you are using a wood mold it will need to be lined with wax paper. Silicone molds are ready without any special preparation.
- Place the glass canning jar on the scale and tare your scale. Pour distilled water into the jar until it reads 6 oz. Set aside.
- Put the second jar on the scale and tare the scale. Wearing your protective gear, carefully pour lye into the jar until your scale reads 2.3 oz.
- Take both jars and your spoon outside. Still wearing your protective gear, slowly pour the lye into the water. Stir the mixture. It will become quite hot so keep this in mind if you need to move it. Let this mixture sit and cool to about 100 degrees.
- While the lye is cooling, measure all other oils EXCEPT the essential oils and warm them together in your pot or slow-cooker. Once they are melted, remove the oils from the heat and let cool until 100 degrees. I use the infrared thermometer about every 5-10 minutes to test the temperature. This works really well. A candy thermometer placed in each container also works. If one is cooling faster than the other you can put your oils back on the heat source or the lye/water mixture in a warm water bath to slow the cooling process a bit. Ideally, you want the lye water and the oils to both be around 100 degrees and within 10 degrees of each other.
- When the temps match, slowly pour the lye/water into the oils. Use the immersion blender to bring the batter to a light trace. It should be slightly thick and resemble cake batter.
- If you are adding essential oils now is the time to do so. Pulse the immersion blender a couple of times to incorporate the essential oils. If you prefer not to use them just skip this step.
- Add salt. Stir until it is evenly distributed.
- Spoon the soap batter into your prepared mold. Remember that the soap is not fully “cooked” yet at this point and could still irritate your skin so you should still be wearing your gear.
- If you are using a silicone mold with individual cavities you are done! Let it sit for 24 hours and then you can un-mold your soap.
- If you are using a log style mold, keep an eye on your soap and as soon as it is set (after approximately an hour) un-mold it and cut it into bars. If you wait too long it will become too hard to cut.
- Stand bars up in a dry area with an inch or so of space in between to allow for air circulation and let them sit for 4-6 weeks. This will allow the soap to complete the saponification process and also dry them out a bit so they last longer in the shower.
Since my skin tends be slightly more oily, I found this soap to be great for my face. If you want an exfoliating option to your normal bar soap, I think you’ll like this recipe!
Do you use salt in your beauty care? Will you try adding it to your soap?
Discussion (50 Comments)
I just made this recipe this morning (about 6 hours ago) and used the molds. From the directions, it sounds like the soaps should be hardening by now, but the texture is like cream cheese. Any ideas why?
Thanks in advance!
Update: I was able to pop them out after 24 hours with no problem! No need to reply. 🙂
Would love to be making soap, I have not ever attempted it because of a certain concern I have.
Could you help with my query ?
In the making of soap, you say wear gloves and eye protection, if this is harmful in the making, then why would I rub it on my skin?
I discuss the chemistry behind it in this article: https://wellnessmama.com/60992/how-to-make-soap/
Can you give me some good substitutes for mango butter? I’m really allergic. I’ve made a few so so batches of castile soap before. I want to try again some time soon. This looks like it would be fun to try.
Try any kind of butter or oil you want. I would run it through an lye calculator though to be safe.
I enjoy your site and have been benefited by it. It has made a difference to our family. THANKS. I appreciate the effort and your generosity (freely sharing your knowledge).
Sea salt is awesome. I recently made a Potassium Hydroxide (Potash) salt hard bar and am really happy with it. It has the lowest pH of any soap I have made (7 on litmus paper). Because of the lack of information on the internet about KOH hard bar soap i had to wing it but it worked. I kept the coconut oil and castor oil content low as the resist thickening with salt in liquid soap. 10% Castor Oil, 10% Coconut Oil, 40% Beef Tallow, 40% Olive Oil. I put that through Summer Bee Meadow lye calculator for KOH and added 20% Himalayan fine ground salt. Some of that didn’t dissolve in the lye water so there were some crystals in the soap, which caused a whitened mottled effect. It didn’t heat up as much as a NaOH soap. I was able to unmould it after about 3 hours. With the pH so low I tried it immediately and it was not like uncured NaOH soap. It was firm but had a slight spongy effect but tolerated water very well. It is quite bubbly, low pH and doesn’t sting my eyes . After 2 weeks it is loosing the spongy effect. This is a very mild, nice soap and an alternative if you have KOH. Hope this is helpful to someone.
Deb, this is so great- thanks for sharing! I am very interested in making KOH hard bars, but as you say, have had trouble finding much good info. Really appreciate you sharing your experiment.
This bar has ended up nice and hard. I am going to try 80% Beef Tallow, 12% Castor Oil and 8% Coconut Oil at 5% superfat with the 20% Salt. This way I can increase the bubbles and cream (soapcalc.net). I can get KOH a lot cheaper bulk at pool chemical outlet than NaOH. I use it for my liquid soap. Have given some of this soap to friends for opinions. Good results with dermatitis and acne. May be a bit drying for some as we head into winter (Australia). An increased superfat may off set this.
Am a bit cautious with oils with high levels of Lauric and Ricinoleic acids as they seem to be the ones that stop salt thickening liquid soap if used in higher quantities (can’t find the exact levels and after problems over 20% think 15% might be my ceiling). Not sure about the reaction on Bees Wax – have used it at 5% successfully but getting a hard KOH seems to have slightly different rules. Will look at adding honey to the bubblier bar for hair washing/ dandruff problems. The salt should be good for fungal issues. Might even go cave man one day and try making my own Potash out of curiosity. Future projects:) All the best.
How many molds do I need for this recipe if I use the individual bar molds that you recommended? PS. I love you and all you write. Such a resource for my Fam.
I was very successful using 2 Crafters Choice Heart shaped Guest Silicone Molds (#1612) This soap fit perfectly in both molds, without any excess! I’m thinking of packaging these smaller soaps for freebies to give away to anyone with a purchase! I’ll make larger bars to purchase! (a few of these will be samples as well!)
Can you use shea butter instead of mango butter, and would it be the same amount?
Yes you can substitute. Run through a soap calculator to be sure but it should be equal amounts.
As you have specified, adding salt reduces the lathering capabilities of the soap. And the ingredients list is full of oils and fat. How does this formulation cleanse an oily tired skin without lather?
All soap recipes are full of oils and fats. The chemical reaction (saponification) from the lye changes the molecules to have one end water loving and one end oil loving = water (universal solvent) can break into dirt/grease and wash it away. The lather is only reduced. Bubbles are cool but don’t clean. Soaps with little lather still are effective eg Castile (Olive oil soap).
Hi! Can you add salt to a foaming hand soap?! I imagine it would need to be incredibly fine if so! Thanks!
You could as long as the texture doesn’t bother you 😉
I make sea salt soap with goats milk, one of my absolute favorites! It doesn’t sell well for me, though. One comment about the type of salt used: I purchased pink Himalayan salt from a soaping supply company to use in my first batch. It looked beautiful, however it scratched my skin so badly (I thought I was exfoliating 🙂 ) I couldn’t use it. My scratched-up areas (which were everywhere) broke out in a dermatitis reaction. Not fun! Using plain sea salt fixed the problem!
I have used salt scrubs and homemade bath salts. I have even used the salt spray on my hair on occasion.
My question is can you add it to a melt and pour recipe, and if so, how much should be added?
I’m not sure, as melt and pour base recipes wouldn’t have the extra superfat percentage and may get weepy with the salt…
Weigh and cut up 14 oz. Detergent Free Coconut Milk MP Soap and place in a glass measuring cup. Cut up an additional 2 oz. and place in a separate glass measuring cup. Heat the 14 oz. of soap in microwave until soap has completely melted.
In plastic beaker, combine 14 ml Coconut Milk Fragrance Oil with 7 ml of Vanilla Color Stabilizer and stir. Set aside for 2 minutes then mix into the melted soap and stir.
To the cup with 2 oz. of unmelted soap, add 0.3 oz. of Smooth and Creamy Lotion Bar Additive. Heat in microwave for about 40 seconds until lotion bar additive has completely melted. Add this into larger cup of melted soap and stir.
Add 1.10 oz. Pink Sea Salts and 1.10 oz. Epsom Salts and stir well.
Place Oval Guest Silicone Mold on a cookie sheet to give it stability when moving. Carefully pour the soap into 8 cavities being sure to stir the soap mixture before each pour. This will keep the salts blended so each bar with have salts in them.
Let sit at room temperature for about 10 minutes then place in freezer for about 30 minutes to set up.
Remove from soap mold and set aside.
Repeat above steps to make second set of soaps.