Back on May 10th, I posted my thoughts and observations about salt soaps. Following the lively discussions here on the blog and on our Facebook page, I asked a few people to help guest write a blog post about making salt soap. Tess volunteered to share her recipe and some pictures.
A lot of people seem to be curious about salt bars, and their reactions range from “Eww, salt in a soap?” to “Hmm, salt in a soap, interesting.”
I personally love salt bars, and make a lot of them. They’re fairly simple to make, and this is my current favorite recipe:
Ingredients in %
* Coconut Oil (76 degree) 93%
Since it’s such a high amount of coconut oil you want to use a large lye discount/superfat, I typically use 20%.
The exact amounts I use for a 18 bar batch in my molds are:
* 44.64 ounces Coconut Oil (76 degree)
1. Weigh out your oils, fragrance, water, and salt. Having things neatly laid out and ready to go makes the experience so much easier and more enjoyable. Have any other additives or colorants measured out and at hand before you start.
2. Add the tuft of tussah silk(if you’re using it) to the water and carefully add the sodium hydroxide to your water, wearing the appropriate safety gear. Stir well, then set aside in a safe place to allow it to cool.
3. While the lye solution is cooling, warm your coconut oil and shea butter until just melted (I use a large stainless pot on the stove over low heat) and remove from heat, then set aside to cool.
4. Exact temperatures aren’t critical, I tend to soap with both the lye solution and butter/oil mixture at 90-100 degrees F, but precision isn’t necessary. Combine the lye solution and oils, mix to a very thin trace. Add your fragrance and colorant at this point, then continue to mix until you’re at a medium trace.
5. At medium trace, start stirring in your salt. The soap mixture will become more difficult to stir as you add the salt, so be mindful of the strain on your immersion blender if you’re using one. I typically switch to a soap spoon at this point. Continue to stir vigorously until you’re sure that the salt is adequately mixed in, then pour into your mold as usual.
**Note** Salt bars can be tricky to cut, if you wait too long, they’re cement-hard and impossible to cut. Ideally, they’re cut within hours of pouring into the mold, sometimes when they’re almost too hot to comfortably handle with thin gloves. After botching the timing and cutting too soon or late one time too many, I started using individual cavity molds for my salt bars and completely avoid the crumbling corners and assorted other pitfalls. Just be sure that your mold can withstand heat, these puppies can get hot.
6. If you’re using a traditional log or slab mold, see the note above and keep a close eye on your soap, you can’t wait until the next day to cut your bars or you’ll need a chisel and hammer and will most likely end up with a big mess. Watch for them to gel, then cut as soon as they’re cool enough to handle with gloved hands. If you’re using cavity molds, you can tuck them away and leave them until the next day, I typically leave them in the molds for about 24 hours and then pop them right out.
7. Allow to cure just like any other CP soap. I actually like to tuck a couple bars away and leave them for a really long cure, they’re absolutely divine after 6 months.
When you use your salt bar, you’ll notice right away that the lather isn’t like your usual CP soap, you’ll get a few big bubbles here and there but the majority of the lather is more of a dense foam like consistency.
You’ll also notice the bars taking on a rounded and weathered appearance and feel with use, they eventually look and feel a bit like smooth river rocks.
A handy tip for determining your batch size and salt amount: Take the usual amount of oils required to fill your mold and multiply by .8, that’ll give you the amount of oils to use, then multiply that oil number by .8 to determine how much salt to use. As an example, the molds I used normally need 60 ounces of oils to fill all three molds.
60 x .8 = 48 so I’ll use 48 ounces of oils
48 x .8 = 38.4 so there’s my salt amount to use
Feel free to experiment with the recipe, some people prefer to use less salt (I received a very nice bar as a gift that was made with 50% salt) and some use an equal amount of salt and oils. You can use milk instead of water in your lye solution, I made a lovely coconut milk batch once, just keep a close eye on them because of the heat. Salt bars tend to get hot, milk soaps then to get hot, so the combination means you’ll really need to keep a watchful eye on them and be prepared to turn a fan on or pop them in the fridge to prevent overheating.
You can omit the shea and make a 100% coconut oil batch, or you can substitute different oils and butters, just keep in mind that you’ll need a lot of coconut to produce any lather, salt is the slayer of bubbles. Be sure to run your modified recipe through a lye calculator.