Exciting news - the liquid soap recipe reveal is here!
Like many of you, I initially hesitated at the thought of making liquid soap due to its complex process and thought “Whoa, That is a ridiculously involved process, and sounds way harder than bar soap… and maybe it’s just not worth the time and effort.” Do you blame us? The processes usually required hours of work and supervision, careful calculations that are different from bar soap, pH testing, neutralizing the final product with acid, and a lot of mess with a potato masher. The primary difference between liquid soap and bar soap is the type of lye you use to convert the oils into soap. Bar soap uses sodium hydroxide. Liquid soap uses potassium hydroxide. My simplified method requires less time, supervision, and cleanup compared to traditional methods.
Basic Liquid Soap
50% olive oil (pomace)
30% refined coconut oil
15% unrefined shea butter
5% castor oil
5% superfat (or lye discount)
Use SoapCalc to get your final measurements of KOH and H2O, based on your batch size (I’d recommend not going smaller than 500g of oils as that starts to get tricky to blend, especially if your pot is quite large). Be sure to check the “90% KOH” box to prevent too much of a superfat—most KOH is only 90% pure, so checking that box accounts for that in the calculations.
Melt the oils together in a large (non-aluminum) heavy bottomed pot over medium heat.
Weigh out the water into a large, dishwasher safe jug.
Weigh out the KOH carefully into a small container and add it to the water, swirling it gently to dissolve the flakes. It will bubble and steam—avoid inhaling the emissions.
Once the oils have melted, turn the heat down to low (2/10 or so) and add the lye water.
Get out your immersion blender and start blending to reach trace—this will take quite some time. After 20–30 minutes of stirring and blending, you will eventually end up with something the texture of pudding or applesauce. At this point, switch out the emulsion blender for a flexible, sturdy silicone spatula—we have achieved trace and are now cooking the paste.
Stir as the mixture continues to cook. There are a lot of cooking stages that you can apparently witness, but all I saw using this hot processed method was runny mashed potatoes to thick mashed potatoes to translucent vaseline like paste. Once you reach the translucent paste stage you’re done—do a zap test to confirm (aka touch a small amount of the paste [let it cool first!] to your tongue—it shouldn’t “zap”).
You’ll want to store most of the paste to dilute as needed—mason jars are great for that.
To dilute, start with a 1:0.6 ratio of paste to water by weight (eg. 100g soap paste, 60g water—you’ll always want to be using more soap paste than water unless you like your liquid soap very firmly on the liquid side of things). I used tap water. Place the paste and water (just-boiled is best) together in a container with a sealing lid. Mash it a wee bit (use a fork rather than a spatula to avoid spurting), and then seal it and leave it. Overnight is a good starting point. The next morning, mash it about a bit and try to break up the blobs of soap paste. Re-heat the mixture a bit, re-seal, and let it sit some more. Continue this until you have a homogenous mixture. Yes, it takes a while, but at least it’s almost entirely downtime.
Now you can add your essential oils—a major bonus of liquid soap is that you’ll need far less essential oil to get the scent you want because they don’t have to live through saponification or aging. Score!
Transfer to a pump-top container and voila, soap!
If you like your soap thicker than it ended up being, You can just add some more soap paste and let that dissolve, but I find that the second soap paste addition takes quite a lot longer to dissolve than the first one—days instead of hours.