Eco-friendly Cold Process Soap Recipe
Natural Vegan and palm-oil free simple cold process soap recipe. Technical information: 1lb / 454g batch -- 5% superfat -- 35.7% water discount
Servings 8 bars
Cost 10
Equipment
- empty milk or juice carton
Ingredients
Lye water
- 63 g sodium hydroxide 2.22 oz
- 113 g distilled water 3.99 oz
Solid oils
- 114 g coconut oil (refined) 4.01 oz (25%)
- 91 g shea butter (refined) 3.21 oz (20%)
Liquid oils
- 227 g olive oil (light colored or pomace) 8.02 oz (light colored olive oil) (50%)
- 23 g castor oil 0.8 oz (5%)
Instructions
- Cold-process soapmaking is chemistry, and this recipe uses lye. Lye is a caustic substance that is completely neutralized in the soapmaking process, but it can be harmful if not handled correctly. Please read this soap making safety guidance before proceeding.
- Prepare your workstation with your tools and equipment. Put on rubber gloves, eye protection, and an apron. Carefully pre-measure the ingredients. The solid oils into the pot, the liquid oils into a jug, the water into another heat-proof jug, and the lye in another container.
- Prepare the recycled soap mold. Rinse out an empty drinks carton and let it dry upside down. When fully dry, cut out the side that the pouring spout is on. A cutting blade is better for this than scissors. Use the cut-out paper to block the open end of the carton. I fold it over the bottom of the carton and then fit it inside the top of the carton. This helps to create a flatter surface on that side of the mold rather than a pointed shape from what was the top of the carton.
- Next, dissolve the lye (Sodium hydroxide) crystals in water. In an airy place, outdoors is best, pour the lye crystals into the water and stir well. There will be a lot of heat and steam, so be careful. Try not to breathe it in. Leave outside in a safe place or in a shallow basin of water to cool.
- Melt the solid oils in a stainless steel pan on very low heat. When melted, remove from the heat and set on a potholder. Pour in the liquid oils. If you have the olive and castor oils in the same container, stir them together first before pouring them into the pan. Castor oil is pretty sticky, and it's easier to pour when mixed with lighter oil.
- Measure the temperatures of the lye solution and the oils. You should aim to cool them both to about 95-100°F / 35-38°C. Use an infrared thermometer or digital kitchen thermometer*.
- Pour the lye solution into the pan of oils. I recommend pouring the liquid through a sieve to catch any potential undissolved lye. You can also pour the lye solution against the side of the stick blender if you'd like to reduce the chance of air bubbles forming in your soap bars.
- Dip the stick blender into the pan and with it turned off, stir the mixture. Next, bring it to the center of the pan, and with both your hands, hold it on the bottom of the pan and blitz it for just a couple of seconds. Turn it off and stir the soap batter, using the blender as a spoon. Repeat until the mixture thickens up to 'Trace.' This is when the batter leaves a distinguishable trail on the surface. The consistency will be like thin custard.
- Working quickly, pour the soap into the mold. Give it a tap to settle it.
- For a truly pure white soap through and through, place the soap in the refrigerator and leave it there overnight. You can also leave the soap sitting on the counter during this time. If the house is warm, there's a small chance of the center gelling, and your bars having slightly darker centers, though.
- The next day, take the soap out of the fridge and set it somewhere to rest for another day. Once 48 hours have passed, you can take the soap out of the mold and cut it into bars using a kitchen knife. You can get six to eight decent-sized bars of soap from this batch.
- Cure it for 28 days. Curing means leaving the bars spaced out on a protected surface out of direct sunlight and in an airy place. This allows the extra water content to evaporate out fully. Here are full instructions on how to cure soap.
- Once made, your soap will have a shelf-life of up to two years. Check the oil bottles that you're using, though. The closest best-by date is the best-by date of your soap. If your handmade soap is destined as gifts, here are some pretty and eco-friendly soap packaging ideas.
Notes
* I've had questions on whether or not you can use an analog candy thermometer for soapmaking. Yes, you could, but it's not quick enough for my liking. Digital thermometers give you almost instant readings.
Lastly, are you a beginner soapmaker looking for more guidance on how to make handmade soap? Enroll in the Natural Soapmaking for Beginners Online Course to get up to speed quickly. You'll learn all about soap ingredients and equipment and be guided through step-by-step soap recipe videos. Learn more