Let’s talk about how to formulate your own salt bar recipe.

orange oatmeal breakfast salt bar

What is a salt bar?

A salt bar is typically a soap made with 50-100% of oil weight in salt. For example, if your salt bar recipe contains 32 oz. of coconut oil and 8 oz. of castor oil, then you would use 20 – 40 oz. of sea salt.

Why on earth would we want to make a salt bar?

  1. Sea salt is purifying, drawing and acts as an astringent. It is great, especially, for acne.
  2. Salt bars last FOREVER in the shower. In my experience, they last longer than regular bar soap. (This is a great selling point.)
  3. Salt bars are hard! Salt soap cures out super hard. Salt bars are great for individual cavity molds that you can’t usually use with your regular recipe. The soap gets hard fast and will pop right out.
  4. They are inexpensive to make. Salt bars contain mostly coconut oil (a cheaper oil than say…olive oil or shea butter) and sea salt, thus creating a pretty inexpensive bar of soap.
  5. They are easily marketed as spa type or facial bars of soap. Customer love to hear about the benefits of sea salt and will pay more money for these special bars of soap.

Base Oils – Coconut Oil

Salt bars usually contain a high amount of coconut oil. You can use 80-100% coconut oil.

Why so much coconut oil?

Salt is a lather killer! It kills the suds. To combat the lather killing effects of salt, we use a high amount of coconut oil.

Some typical oil combinations include:

  • 100% coconut oil
  • 80% coconut oil + 10% butter + 10% liquid oil
  • 90% coconut oil + 10% butter
  • 90% coconut oil + 10% liquid oil

Liquid oils can be any liquid soapmaking oil…castor oil, olive oil, avocado oil, rice bran oil…whatever your favorite is.

Butters can include shea, cocoa, mango, sal, kokum…or whichever cosmetic butter you prefer.

Superfat – 20%

What do we know about coconut oil in high percentages?

It can be drying. To combat the drying effects of using high coconut oil, we use a high superfat to leave oils unsaponified to make our soap moisturizing and nourishing. A typical superfat for a salt bar is 15-20%. I usually use 20%.

In a recipe not containing salt, this might make our soap mooshy or soft. But not in a salt bar. The salt helps to harden the soap. Even using a high superfat of 20%, this soap turns out super hard.

Salt – Which to use?

There are many different types of salt. Most any type of salt will work except dead sea salt. My favorite salt to use is fine sea salt. I get mine from Wholesale Supplies Plus.

Dead sea salt is actually more mineral than salt. It makes for a weepy, wet and yucky salt bar. Check out Amy’s post where she learned the hard way.

I don’t use Epson salt either. I’m not sure if that works or not…

Size doesn’t really matter. I prefer fine grain, but you can use up to large grain. It all melts with the warm water so isn’t that scratchy or exfoliating.

For varied color, you can use pink salt. I love this pink sea salt from Bramble Berry.

How much salt do you use?

You can use anywhere from 50% – 100% of your oil weight in salt.

Individual Cavity Molds

Salt bars get hard fast! It is best to use individual cavity molds when making salt bars. My favorite mold for salt bars this mold from Bramble Berry. I love the way the half cylinder bars fit in my hand.

If you pour salt soap into a loaf mold, you have to monitor it closely and cut it before it gets to hard. This can be 4 hours after you pour or 8. Sometimes it is hard to tell when they are ready to cut.

Let’s formulate a salt bar recipe!

Step 1How much soap will your molds hold?

I’m going to use the above Bramble Berry molds for this example. I want to fill up two of the molds. Each cavity holds 4 oz. for a total of 48 oz. of soap (oils + water + lye + salt). There is no easy formula to determine your oil amount because everyone uses a different amount of salt; some use 50%, some use 100%.

Step 2Formulate your base oils.

Let’s take a shot in the dark and start with a recipe that uses 24 oz. of coconut oil. Plug 24 oz. of coconut oil into soapcalc.net with a 20% superfat. For water, I ignore soap calc and when formulating salt bars, I simply multiply the lye amount by 3. So we end up with a recipe of :

  • Coconut oil – 24 oz.
  • Lye – 3.4
  • Water – 10.5

Step 3Determine how much salt you want to use.

Let’s see what it looks like with 50% salt and 100% salt.

  • 50% Salt Bar
  • Coconut oil – 24 oz.
  • Lye – 3.4 oz.
  • Water – 10.5 oz.
  • Salt – 12 oz.
  • Total oz. (49.9 oz.)
  • 100% Salt Bar
  • Coconut oil – 24 oz.
  • Lye – 3.4 oz.
  • Water – 10.5 oz.
  • Salt – 24 oz.
  • Total oz. (61.9 oz.)

Since our molds will hold 48 oz. of soap, the 50% salt bar will fit nicely. If we want to use 100% salt, we will need to scale the recipe down.

  • 100% Salt Bar
  • Coconut oil – 19 oz.
  • Lye – 2.7 oz.
  • Water – 8.1 oz.
  • Salt – 19 oz.
  • Total oz. (48.8 oz.)

This 100% salt soap will fit in our molds.

Step 4 – Fragrance or Essential Oil

I calculate my rates based on the amount of oil in my recipe. For salt bars, I calculate based on the amount of oil + salt.

My standard rate for fragrance oil is .7-1 oz per pound of oil + salt. My standard rate for essential oil is .5 oz per pound of oil + salt. Rates vary depending on the strength of your oils, but these are good starting off points.

  • 100% Salt Bar with fragrance oil at 1 oz. per pound of oil + salt
  • Coconut oil – 19 oz.
  • Lye – 2.7 oz.
  • Water – 8.1 oz.
  • Salt – 19 oz.
  • Total oil + salt = 40.7 oz.
  • FORMULA 40.7 / 16
  • Fragrance oil = 2.5 oz.
  • 100% Salt Bar with essential oil at .5 oz. per pound of oil + salt
  • Coconut oil – 19 oz.
  • Lye – 2.7 oz.
  • Water – 8.1 oz.
  • Salt – 19 oz.
  • Total oil + salt = 40.7 oz.
  • FORMULA (40.7 / 16) * .5
  • Essential oil = 1.27 oz. (round to 1.3 oz.)

Step 5 – Add your colorant.

Most of the time colorants are simply a matter of preference. You can start with adding 1 teaspoon per pound of oils of mica, pigment or natural colorant and go up from there based on the color that you are trying to get.

So in the above example, you would add 2.5 teaspoons of a colorant and see how it looks. Adjust if more is needed to achieve the color that you want.

Our Final Recipe:

  • 100% Salt Bar with essential oil
  • Coconut oil – 19 oz.
  • Lye – 2.7 oz.
  • Water – 8.1 oz.
  • Salt – 19 oz.
  • Essential oil = 1.3 oz.

Equipment Needed
Digital scale
Containers for measuring & mixing lye solution
Container for mixing soap
Spatula or spoon
Individual Cavity Molds

Salt Bar Process

Step 1 – Wearing safety gear, make your lye solution by weighing out the lye and water into separate containers. Sprinkle the lye into the water while stirring. Stir until dissolved and set aside to cool.

Step 2 – Weigh out coconut oil and melt.

Step 3 – Add the essential oils, additives and colorant to the melted coconut oil. Stir.

Step 4 – Check the temperatures of your lye solution and oil mixture. Each should be under 90 degrees F. If not, let cool a bit longer.

Step 5 – While stirring the oil mixture (with stickblender off), pour lye solution into the oils.

Step 6 – Using short bursts with your stickblender, mix until light trace has occurred.

Step 7 – Mix in fine sea salt. Mix well. Pour the soap into your molds.

Step 8 – Allow to sit and harden. You can usually unmold salt bars the same day. Allow to cure for a minimum of 4 weeks.

Enjoy your salt bars!

I hope this helps you when you formulate your own salt bars! If you have any questions, post in the comments.

Happy Soaping!

Amanda Gail