charcoal menthol face

Step 1: Make the Lye Solution
Wearing gloves, goggles and long sleeves, weigh the distilled water into a stainless steel or heavy duty plastic pitcher. I use an old Tupperware pitcher or heavy duty plastic buckets from the paint section of my local DIY store. Look for plastic with a recycle symbol number 5 on it and it should be good to use. (Never use aluminum utensils or pots when making soap as it will react adversely with lye.)
Next, weigh the lye into a small cup or container. Sprinkle the lye into the water (not the other way around or you might get a lye volcano) and gently stir with a heavy duty plastic or silicone spatula or spoon until the lye is completely dissolved. The temperature will get really hot. Work near an open window, outside or under an exhaust fan. Avoid breathing in the resulting strong fumes that linger for a few moments. (If you have sensitive lungs, breathing problems, or are concerned about the fumes, consider wearing a mask such as THIS ONE.)
Carefully stir the activated charcoal into the hot lye solution. (Alternatively, you can dilute the charcoal with twice as much water and add it at trace. Both ways give a similar color.)
Set the lye solution aside in a safe place where it won’t get disturbed and allow it to cool down for around 30 to 40 minutes, or until temperature reaches around 100 to 110°F (38 to 43°C)
Step 2: Weigh and Heat the Oils
Weigh out the cocoa butter and coconut oil and heat gently until melted. Add the other oils. If needed, you can heat the combined oils and butter further until the temperature is around 90 to 100°F (32 to 38° C).
(You don’t have to be extra fussy with temperatures though. Some like to make soap at room temperature, while others prefer even hotter temperatures than I use. There’s a wide range of personal preferences that work just fine.)
Add the powdered milk to the oils and stir in by hand or with your immersion blender.
If you’d like to ensure that your soap has a longer shelf life, add 1 gram (about 40 drops or 1/4 teaspoon) of Rosemary Antioxidants to the warmed oils.
You can buy Rosemary Antioxidants from Mountain Rose Herbs. Since you only need a tiny bit per batch of soap, one bottle will last for ages and is well worth the extended shelf life it provides.


Step 3: Combine and Mix Until Trace
Pour the lye solution into the warm oils. Using a stick or immersion blender (looks like THIS and is not a handheld mixer) stir the solution with the motor off for around 30 seconds. Turn the motor on and blend for half a minute or so. Stir for another 30 seconds with the motor off, then again with the motor on and so forth. Don’t run the stick blender continuously so you don’t risk burning out the motor and/or causing excessive air bubbles in your finished soap.
Alternate with this method until trace is reached. “Trace” is when your soap batter gets thick enough to leave an imprint or tracing, when you drizzle some of it across the surface. Above is a picture of a soap batter at a medium trace.
Hand-stir in any essential oils, if using.


Step 4: Pour Into Mold(s)
This is a cold process soap recipe, which means you don’t cook it or add any extra heat, so at this point it’s ready to pour into the mold(s).
After pouring, cover the mold(s) gently with a sheet of freezer or parchment paper, then a light blanket or towel to help hold in the heat.
Peek at your soap every so often. If you see a crack developing down the middle, it’s getting too hot, so move the mold to a cooler place in your house.
You might see the soap change from darker to lighter colors in spots and even take on a translucent, jelly type texture, especially in the middle. That’s all perfectly normal – it just means your soap is going through gel phase.
After 24 hours, remove the freezer paper and blanket/towel, then let your soap stay uncovered in the mold for 1 to 2 days or until it’s firm enough to release fairly easily. If needed, you can pop the mold(s) in the freezer for 4 to 6 hours until completely solid, then try removing.


Step 5: Cure and Enjoy!
If you used a loaf mold, after unmolding your soap, allow it to cure in the open air for a few days before slicing into bars.
Cure the soap on wax paper or coated baking racks for 4 to 6 weeks before using, though I usually start testing a bar at 3 weeks for personal use.
Shelf life of homemade soap is often given as one year, but it will depend on the quality of ingredients you start with and how it’s stored. Keep your finished soap in a cool area away from excess heat, sunlight and humidity.