Recipe and instructions for how to use fresh herbs and colored clay to make Natural Rosemary Soap using the cold-process method
This is a natural soap recipe that blends together two special ingredients. Rosemary, in two forms, adds scent, decoration, and anti-bacterial properties. Cambrian blue clay is a cosmetic ingredient that can tint soap a soft green-to-blue. It also has oil-drawing properties that benefit those with oily skin. Together, the herb and the clay create a beautiful rosemary soap recipe, the bars of which you can use for hands, body, and face. The recipe includes all-natural Vegan oils and is suitable for intermediate soap makers.
What I like about this recipe is that it’s very gentle, cleanses well, and looks attractive. Though I’ve created the recipe specifically for oily skin, it’s suitable for everyday body-use with those with normal skin. The rosemary essential oil smells incredible, and you could use homegrown rosemary to personalize your bars.
Blue Clay Colors Soap
You may have found this recipe through my popular piece on natural colors for handmade soap. There are many wonderful natural ingredients that you can use to add color to soap but some have other attractive properties too. Cambrian blue clay is a natural element mined from areas in northwest Russia and it naturally colors soap shades of green to blue. You can also use the clay in beauty products for its oil pulling ability and it’s common to use in face masks. In soap, it’s mainly used for coloring but it can also work to gently cleanse oily skin.
Clay not only pulls oil, but it attracts and captures minerals in the sediments where it forms. In blue clay’s case, the color comes from it having a high content of chemically reduced iron. This special mineral has been linked to its ability to naturally eliminate bacteria, including those that cause breakouts. So blue clay is a win-win in that it cleanses oily skin, reduces the microbes that cause pimples, and creates a lovely color.
Rosemary is Anti-bacterial
Like blue clay, rosemary oil kills bacteria, especially Propionibacterium acnes, the type that causes pimples. That makes rosemary ideal for gently treating problematic skin. However, the essential oil is the more important rosemary ingredient in this recipe. Most people think that essential oils are scented herbal perfumes but they’re actually concentrated plant essences with therapeutic properties. To make just the smallest bottle of rosemary essential oil it takes an entire pot of rosemary leaves and a very complicated process.
Which brings me to the fresh rosemary that I’ve included in this recipe. This rosemary more or less for decoration and exfoliation and will have very little therapeutic power. When chopping the rosemary for this recipe I recommend that you get the pieces as small as possible. I can tell you first hand that the last thing you’ll enjoy in the shower is a soggy piece of black leaf surfacing on your soap. Not only do they look icky but larger pieces can also be scratchy. If in doubt, you can always leave the rosemary leaves out — they’re completely optional.
Making this Rosemary Soap Recipe
If you’re new to making natural handmade soap, you should read my four-part series on natural soap making. It gives a good introduction to what to expect from ingredients, equipment, and cold-process soap recipes. The series gives a good foundation for making all handmade soap including this cold-process rosemary soap recipe. One section that’s especially important to read is the part on equipment and safety since it will prepare you for working with lye.
Natural Rosemary Cold-Process Soap Recipe
- Stainless steel pan for melting the solid oils
- Rubber gloves
Add after Trace
- 4 tsp Rosemary essential oil 14 g / 0.49 oz
- 3 tsp Rosemary leaves (chopped finely) Optional
To prevent Soda Ash
- Rubbing alcohol (99% Isopropyl Alcohol) in a spray bottle
Prepare your Soap Making Station
- Ensure that your kitchen workspace is clean and set up with all of your tools, ingredients, and equipment. Please also prepare yourself by wearing long sleeves, closed-toe shoes, goggles, and plastic gloves. Soap making is fun but also chemistry so you need to work safely.
Make the Lye Solution
- A couple of hours before you make soap, put on your goggles and gloves, and make the lye solution. You should do this in a well-ventilated area and try not to breathe in the steam. Measure the sodium hydroxide (lye) into a container and the distilled water into a heat-proof jug.
- Pour the sodium hydroxide into the water and stir very well. It will be very hot at this point so be careful. Set the jug someplace safe and leave the lye mixture to cool to just above room temperature 27 °C (80 °F).
- While the lye solution is cooling, measure the solid oils into the pan and the liquid oils into a jug.
- Finely chop the rosemary. Fresh leaves are better for this recipe but dried is fine too, although more difficult to chop finely. The rosemary pieces eventually add dark, dried specks to your bars and you can feel them as you use the soap too. If they're not small, then they can be scratchy. You can also make this recipe without the rosemary leaves if you wish.
- In a ramekin, mix the clay with the extra water. The extra water amount helps mix the clay into the soap batter and it also stops the clay from making your soap crack.
Melt the Solid Oils
- When the lye solution is room temperature, stir in the sodium lactate. The amount listed is for liquid sodium lactate so if you're using powdered sodium lactate, just use half the amount given.
- Place the pan of solid oils on the hob and turn it on to the lowest heat setting. They will melt quicker than you expect, so stay with the pan, moving the oil around in the pan to help speed up melting. When there are a few small pieces of solid oil still floating, take the pan off the heat and set it on a potholder. They'll melt with the residual heat and some gentle stirring with your spoon/spatula.
Add the liquid oils and clay
- When the solid oils are fully melted, pour the liquid oils into the pan of melted oils. To minimize air bubbles getting in, try pouring the liquid oils onto a clean spatula held over the pan of oils. Use the spatula to get every last drop out of the jug then stir the oils together gently.
- Next, pour the clay mixture into the pan. Use a spatula to scrape all the color out of the container and into the pan. Don't be alarmed if you see blobs of color at the bottom of the pan.
- Take the temperature of the pan of mixed oils and clay. You're aiming for around the same temperature as the lye solution, but they can be a few degrees higher of 27 °C (80 °F). If they're too hot, floating the pan in cool water whilst stirring helps to cool them quickly.
Bringing the Ingredients to 'Trace'
- When the temperatures are right, pour the lye solution through the sieve and into the pan of oils.
- Carefully place the head of the immersion blender (stick blender) into the oils. Insert it at an angle so that any air inside the head can escape as you submerge the head. Air trapped inside the head can create air bubbles in your soap.
- The next step, bringing the ingredients to trace, is best shown in the video at the bottom of this recipe. Have a watch to understand all the steps better, but especially this one.
- Stir the contents of the pan gently, using the immersion blender as a spoon. Then bring it into the center of the pan and hold it against the bottom of the pan. Not moving the immersion blender, pulse for a couple of seconds. Then gently stir. Keep repeating this pulse then stir process until the soap thickens to a light to medium trace. You'll see just the faintest trace marks on the surface of the soap and it will still be pourable. Stop blending, tap off the immersion blender's head, and put it aside. You will not use it again.
- Add the rosemary essential oil and gently stir with a spatula until completely mixed in.
- Sprinkle the chopped rosemary into the soap batter and gently stir it in.
Molding and Curing
- Pour the soap batter into your mold(s), generously spray the surface with the rubbing alcohol (isopropyl alcohol), and set the soap aside. Come back again after fifteen minutes and spray the surfaces again — the alcohol creates a barrier on the soap and helps stop soda ash from forming.
- Leave the soap to harden up inside the mold for at least 48 hours before taking it out. It may be a little sticky when removing, especially if you decide not to use sodium lactate. In this case, you can leave the soap in the mold for longer, even a week or more. You can also put the entire mold in the freezer for 30 minutes to an hour. They should pop out easily after that.
- Next, find someplace in the house that's safe from animals and kids and that is airy and out of direct sunlight. Lay a piece of baking paper down and space your bars of soap out over it. You should leave your soap there for four weeks to allow excess water to evaporate out of your soap and for them to fully harden up. This is called curing soap.
- This soap's lather is stable and creamy and the color of the soap will be grey-green to grey-blue depending on the quality and color of your olive oil. There’s a clip of the lather in the video below. When fully cured, you can begin using the soap and gifting it to others. Try these creative and eco-friendly ways to package soap for holiday gifts.
- Once made and cured, your soap can have a shelf-life of up to two years. Check the oil bottles and ingredients that you're using though — the closest best-by date of any of them is the best-by date of your soap.
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