Small batch of natural carrot soap with carrot puree to add a sunny yellow color. Makes five to six bars. Technical information: 1lb / 454g batch -- 5% superfat -- water discount due to water content in purée
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.
Make the carrot purée. The amount you'll need for this recipe is around half of a medium sized carrot. I'd prepare and cook a whole one though, just in case. Peel the carrot and slice it up as if you were going to make boiled carrots for a meal. Simmer in hot water until completely soft then remove from the water with a slatted spoon. Blend into a purée with your immersion blender. You can save the water the carrots cooked in to use to make the lye solution but make sure to cool it to room temperature first.
Get yourself prepared. Wear long-sleeves, pants or a long skirt, and closed-toe shoes. Always wear eye protection, such as goggles, and rubber gloves, when handling lye or the soap batter once lye has been added.
Dissolve the lye (Sodium hydroxide) crystals in the water. In an airy place pour the lye crystals into the water and stir well. I prefer doing this step outdoors when possible because of the steam that will come off it initially. It's not pleasant if you accidentally breathe it in so avoid this by holding the jug well away from you.
When fully mixed and the steam has started to dissipate, add the carrot purée and gently mix well. Although other recipes will have you add it at another part of the process, I feel that the lye-solution helps break down any remaining fibers in the purée. The color is also unaffected.
Leave the lye-solution in a safe place outside or inside, but in a shallow basin of water, or sink, to cool. Ensure that children and animals cannot get into it.
Melt the solid oils in a stainless steel pan on very low heat. When melted, remove from the heat and set on a pot holder. Pour in the liquid oils and stir.
Measure the temperatures of the lye-water and the oils. You should aim to cool them both to be about 100°F / 38°C. You don't need to be on the dot but aim to have them at that temperature or slightly cooler.
Put your gloves and googles back on if you've taken them off. Pour the lye-solution through a sieve and into the pan of oils. The sieve will catch any rough bits of carrot and any undissolved lye. Discard the bits you strain out.
Dip your immersion 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 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 distinguishable trails on the surface. The consistency will be like thin custard at first but it will thicken quickly so make sure to work quickly after this point.
If you'd like to add the optional essential oil, stir it in at this point. Pour it in and stir gently until fully blended in. May Chang is a gorgeous citrus scent that holds its fragrance in soap.
There are many types of molds that you can use but I'm using a simple set up. It's a chinese take-away container like you'd get rice or noodles in. To keep the soap from sticking inside, I've lined it in baking paper, shiny side up. The flaps on all sides are to help pull the soap loaf out. You can use your choice of silicone or other types of mold though.
Pour the soap into the mold and set it on a heat-proof surface. I usually pop mine in the (cold) oven at least overnight. Leave the soap in the mold for at least two days. A week might be even better since this is quite a soft soap initially. Soap recipes that are high in extra virgin olive oil tend to start off soft and turn very hard over the curing phase.
Once that time has passed, you can pop the soap out and cut it into bars. Use an ordinary kitchen knife and if you find the soap is sticky just stop and let the soap sit for a few more days. This is a soap high in olive oil and has a lot of water content. It will be sticky and soft at first but over time will harden.
After cutting the bars cure them for six weeks. 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 fully evaporate out. It also allows the bars to harden up. You might find that your soap bars look a bit oily or wet after cutting them up. This happened to one of my batches and I just left it. Over time the bars cured nice and hard and dry.
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.
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