A cold process soap recipe for a rainy day!
One day, when we were talking about future recipes for our blog, we had the sudden desire to make a grey soap. Why grey? Well, just because we didn’t have one yet—even though we have recipes for just about every colour. Next, we wondered what shade of grey we should use. After all, grey famously comes in so many! A stroke of genius hit us… why not use several? And thus Greydient was born: a DIY soap with a beautiful grey gradient!
Beyond this homemade soap’s elegant slate tones, we’re also really fond of the swirl technique in this recipe. This technique requires that you set up your mold in advance and work at medium trace, which lets you make a beautiful soap relatively easily. If you’ve never tried making swirls before, we recommend starting out with our “My First Swirled Soap” recipe. Once you’ve got that recipe down and you’re comfortable identifying trace, you should be able to make this one without a hitch.
See how gorgeous greys can be with our Greydient soap recipe!
How to make soap with beautiful swirls
Sodium hydroxide solution
Oil and butter mixture
- 187 g (15.48%) coconut oil
- 136 g (11.26%) kokum butter
- 451 g (37.33%) olive oil
- 43 g (3.56%) grapeseed oil
- 34 g (2.81%) castor oil
Essential oil blend
- 5.6 g (0.46%) titanium dioxide
- 4 g (0.33%) black oxide
- Large Pyrex cup or high-density polyethylene (HDPE) jar for the sodium hydroxide solution (minimum capacity of 500 ml)
- A jar, for weighing the sodium hydroxide
- Components to make a double boiler
- Immersion blender
- Two large stainless steel bowls
- Four small silicone spatulas
- Regular-sized silicone spatula
- Scales, accurate to 1 g and 0.1 g
- A few pipettes
- A few spoons
- A few ramekins
- Four measuring funnel pitchers
- Silicone loaf mold
- A clean tea towel large enough to wrap around the mold
- Three dividers made out of cardboard or corrugated plastic, cut to the size of the mold (for our loaf mold, they should measure 20.5 cm by 8 cm or 8 inches by 3 inches)
- A knife or a soap cutter
Good to know!
- The saponified oils and butters provide your homemade soap with these wonderful properties:
- Coconut oil hardens your soap, cleanses, and provides great lather.
- Kokum butter hardens soap and provides a silky, creamy lather.
- Grapeseed oil makes this a lovely, gentle soap.
- Olive oil makes this soap very mild on your skin.
- Castor oil makes the soap milder and adds stability and creaminess to the lather.
- To make this homemade soap, you need to pour four colours side by side, using the dividers to keep them separate. You need to wait until the batter has reached medium trace to make the swirls, so that the different colours stay in place when you remove the dividers.
- This soap recipe uses a water to sodium hydroxide ratio of 1.75. This soap is superfatted at 8% through the “lye discount” method, which involves reducing the volume of sodium hydroxide.
Steps to follow
- Prepare and disinfect your equipment and workspace.
- Place your three dividers lengthwise in the mold.
- Take the necessary precautions for handling sodium hydroxide safely.
- Prepare the sodium hydroxide solution: weigh the water in a Pyrex measuring cup or HDPE pot, weigh the sodium hydroxide, pour the sodium hydroxide into the water, mix well, and set aside to cool.
- Weigh the coconut oil and kokum butter in a large bowl. Melt gently.
- Weigh the olive, castor, and grapeseed oils in the second large bowl.
- Weigh the essential oils in a ramekin.
- When the kokum butter and coconut oil have melted, pour them into the bowl containing the oils from step 6.
- Weigh the colourant for the white soap batter in a measuring funnel pitcher. Repeat for the remaining three shades in the other three pitchers.
- Add about a tablespoon of the melted oil and butter mixture from step 8 to each measuring funnel pitcher. Disperse the colourants thoroughly using a small spatula. We recommend having one small spatula for each measuring funnel pitcher to prevent the colours from mixing.
- When the oils and butter mixture and the sodium hydroxide solution have both cooled to 35–40°C, pour the sodium hydroxide solution into the melted oils and butter. Mix with the immersion blender and the spatula until homogeneous.
- At light trace, add the essential oils. Mix well with the immersion blender.
- Don’t wait for the batter to reach trace again. As soon as the essential oils are mixed in, divide the batter evenly between the four measuring funnel pitchers. Mix each batter with its spatula to evenly colour the batter.
- Mix each of the soap batters with the immersion blender until they reach medium trace.
- Pour one colour into each compartment, from darkest to lightest.
- Once all four batters have been poured, gently remove the dividers.
- Place the mold in front of you, horizontally. You’ll be making tightly spaced straight zigzags in the batter by dragging the tip of a thermometer through it, cutting back and forth across the stripes you have created. Gently dip the tip of the thermometer into the upper right-hand corner of the soap mold and plunge it fully down to the bottom of the mold. Then, draw the thermometer towards you in a straight line, until it reaches the lower right-hand corner of the mold. Slide the thermometer a little to the left, still on lower side of the mold (the side nearest you), then draw it back of towards the “top” of the mold (the side furthest from you). Slide the thermometer a little to the left again, now at the top (far) side of the mold, then draw it back down towards you. Repeat this process across the entire length of the mold. You can make the lines closer together or further apart depending on the effect you want.
- Once you have created zigzags along the whole length of the mold, gently remove the thermometer from the soap.
- Now you’ll be dragging the thermometer tip around the edge of the molded soap. This technique bends the zigzags, giving them movement. Gently place the thermometer tip back down in the upper right hand corner of the mold. Slide the thermometer along the edge of the mold to the bottom right hand corner. Continue sliding the thermometer clockwise around the whole mold, keeping the thermometer close to the walls of the mold. Repeat this process several times, always in the same direction.
- Surround, but do not cover, the mold with a clean tea towel to help keep the heat in. Let the soap harden for 24 to 48 hours.
- Wear gloves to unmold the soap. Set the soap on a cutting board and cut it into three even pieces with a soap cutter or knife. Set each of the three pieces on its side, and cut each into three pieces lengthwise, yielding nine soap bars in total. Leave the soap bars to cure in a cool, dry place for four to six weeks.
Use and conservation
This homemade soap is formulated for all skin types. It has a superfat of 8%, making it particularly suitable for sensitive and dry skin—and for winter weather!
When made in optimal sanitary conditions, it will keep for at least 12 months.