How to Make Salt Soap Bars

  • 01 of 06

    How to Make Salt Bars

    salt soap bars
    A variety of salt soap bars. David Fisher

    If you're looking for a way to combine the cleansing, exfoliating and detoxifying qualities of a salt bath with your handmade natural soap, you can combine them in a "salt bar."

    Salt soap bars - or salt bars as they're generally called combine the best of both natural soap and a sea salt bath. The final bar is super hard, and produces a "lotion-like" lather - creamy and low - and many people (including me) love the way they make your skin feel!

    You basically make them like any other cold processed soap with three big exceptions:

    1. Adjust your recipe so that it contains at least 70-80% coconut oil. The salt counteracts the lather of the soap, so the high coconut amount is needed to make lather. (No, I hear you asking, the coconut oil isn't drying in these bars. Most soap makers will up the superfat a little - I generally up it to about 8% - but these bars are not drying.)
    2. Add salt at trace - what will seem like a LOT of salt. There are three general traditions when it comes to the amount of salt used in salt bars:
      1. 100% of the soap amount - that is, if your recipe makes 2 lbs. of soap, you add in 2 lbs. of salt
      2. 100% of the oils in the recipe - that is, if your recipe has 24 ounces of oil in it, you add in 24 ounces of salt
      3. Some lesser amount of salt - I know soap makers who will do 50-70% of the total oils and are happy with their bars.
    3. Unmold and cut the soap as very soon as it sets up - often in as little as 2 hours after pouring.

    So gather up your soap making gear, a big container of salt, and let's make some salt soap bars.

    Continue to 2 of 6 below.
  • 02 of 06

    Create Your Salt Bar Soap Recipe

    mixed soap ready for the salt to be added
    Mixed soap ready for the salt to be added. David Fisher

    The first thing to do is create the recipe you're going to use for the soap. For your recipe, you're going to use a lot of coconut oil.

    For these bars to lather at all, you need to use a lot of coconut oil. So a basic recipe like this:

    • 30% coconut
    • 30% palm
    • 35% olive
    • 5% castor

    should be modified to:

    • 75% coconut
    • 10% palm
    • 10% olive
    • 5% castor

    Some folks will keep it really simple and just do 80% coconut and 20% olive or some other single oil. I think more complex combinations of oils make better lather, so I'll tend to use more oils in a recipe - even if they're only in small amounts.

    The recipe I used for this batch was:

    • 19.5 oz coconut (75%)
    • 2.6 oz. lard (10%)
    • 2.6 oz. sunflower (10%)
    • 1.3 oz. castor (5%)
    • 4 oz. lye (approx 8% superfat)
    • 8.5 oz. water

    Feel free to use your own mix of oils. (I used lard instead of palm and sunflower instead of olive in my recipe - but palm and olive would have been wonderful as well.) But, as always, when you adjust or change an ingredient in your recipe, be sure to run the new recipe through a lye calculator.

    Mix your lye solution, measure and melt your oils, and blend the lye and the oils just like you would in any other cold process soap batch.

    Continue to 3 of 6 below.
  • 03 of 06

    Add the Salt to Your Salt Soap Bar Batch

    adding the salt to the soap batch
    Adding the salt to the soap batch. David Fisher

    Once the soap has reached a really light trace, and you've added your fragrance or essential oil, it's time to add the salt.

    As I said earlier, there are a few schools of thought when it comes to how much salt to add:

    1. 100% of the entire soap batch amount
    2. 100% of the oils in the recipe
    3. Some lesser amount of salt - often 50-70% of the total oils in the recipe

    Using the recipe on the previous page:

    1. 100% of the soap amount = 38.5 oz. of salt
    2. 100% of the oils in the recipe = 26 oz. of salt
    3. Some lesser amount of salt - often 50-70% of the total oils in the recipe = 13 to 18.2 oz. of salt

    I have made batches with all three methods. Method #1 is the hardest and saltiest but has the lowest lather. Method #3 has the least salt but is the most like normal soap. I tend to prefer #2 - it's a good balance of salt and lathering ability.

    There's no special technique necessary to add the salt, just dump it into your soap pot and start stirring vigorously.

    Continue to 4 of 6 below.
  • 04 of 06

    Pour the Soap

    scooping the salt bar soap into the mold
    Scooping the soap into the mold. David Fisher

    Pour or scoop the soap into your mold. It will be a lot thicker than your normal batches of soap. After you've poured the soap, it also helps to tap/thump/slam the mold onto the counter to help dislodge any air that may have gotten trapped under the soap.

    Continue to 5 of 6 below.
  • 05 of 06

    Cut the Soap SOON!

    salt soap bars
    Salt soap bars - a little bit crumbly. David Fisher

    Don't go too far away!

    The salt soap will start to harden almost immediately! If you're using a log mold like I used in the previous picture, you'll want to cut the soap as very soon as possible - as soon as it's firm enough to cut. The soap will still be warm even as it's going through the saponification process.

    If you wait too long, the soap will be super hard, and really hard to cut. I waited just a bit too long on the bars pictured here. You can see the crumbly edges and a couple of bars that fell apart. They're perfectly usable bars...just crumbly.

    Continue to 6 of 6 below.
  • 06 of 06

    Using Divider Molds or Single Cavity Molds

    salt bar batch using slab divider mold
    Salt bar batch using slab divider mold. David Fisher

    Another really great option for salt soap bars is divided slab molds like this one - or even single cavity molds where each mold holds one bar of soap.

    With the slab divider mold, be sure to line the bottom of the mold with freezer paper. The dividers will come out fairly easily, but if you don't line the bottom of the mold with freezer paper, you'll have a very hard time getting the bars separated from the bottom of the mold.

    With single cavity molds, you don't have to rush. Just let the bars set and cool overnight. They should pop right out of the molds quite easily.

    A few more tips...

    • I generally just use regular, fine grain sea salt for my salt bars. You do not want to use epsom salts. The magnesium in the bars makes them gooey, sweaty messes.
    • You can use pink, himalayan or other unique soaps as long as they don't have high "other" mineral content - like dead sea salt, for example.
    • You can add colorants and additives to salt bars just like other soap, just remember that you don't have a lot of time to manipulate the soap. It's going to thicken quickly.
    • Some folks find that the salt seems to lessen the fragrance oil effectiveness - and hence will lean towards a more generous helping of fragrance oil in the batches. I find that .7 ounce per pound of oils (a pretty general usage rate) of fragrance is fine.

    Enjoy this exotic and fun soap variety!