How to make natural carrot soap using the cold-process method. It’s a simple homemade carrot purée that creates that sunny yellow color. Full DIY video included
There are so many natural colorants that you can use to tint soap that it’s ridiculous. Although some are a little exotic, others grow much closer to home. In fact, you might even have the key ingredient for this soap recipe growing in the garden.
Carrots, when added as juice or purée, color handmade soap yellow. They’re also mild, easy, and inexpensive to work with. In case you’re wondering, it’s natural beta carotene (Vitamin A) that tints both the carrots and your soap in the end. Though you can buy it as capsules, it’s far more rewarding to work with raw ingredients. It won’t tint your skin yellow but it will create lovely sunny bars that look vibrant for ages.
Adding purées to soap
This is an intermediate soap recipe, albeit one that’s easy to replicate even as a beginner (check out my beginner soap making series). The key is in following the recipe and ingredients closely. Purées, especially made with fruit, have additional sugar. This additional sugar can heat up your soap after its molded and can cause all kinds of weird and wonderful (and annoying) things to happen. If soap gets too hot it can crack or discolor. If it stays a moderate temperature it can gel, and the color intensify.
Fortunately, carrots are relatively low in the sugars that cause soap mishaps. I’ve also introduced them into the recipe in the lye-solution stage so that any pieces can be filtered out before they’re added to the oils. Making homemade carrot purée is easy but missing chunks is easy too. Little pieces of carrots in soap would not only look and feel vile but could cause spoilage issues too.
Water discounting with purées
Getting the moisture balance right when using purées in soap can be tricky. Fruit and vegetables contain water and if you don’t accommodate for that, then your batches might be wetter than you planned for. That’s why you use a reduced amount of water when making soap with fresh plant material.
Saying that, I’ve found that if you reduce the true water content too much then the soap can trace (harden) very quickly. The amount of moisture in this recipe is much higher than I’d use ordinarily but it gives more time to work with the soap.
The thing you should expect from this recipe is that the soap can be soft and sticky after unmolding. That extra water needs extra time to evaporate out. I recommend leaving the soap in the mold for a week or so before taking it out and cutting.
Different shades of yellow
In the recipe we use a normal soaping temperature. We also allow the soap to cool down and harden at around room temperature. To get an even more vibrant yellow-orange color you can also gel this soap recipe. That involves using a slightly higher soaping temperature and insulating it to retain heat.
To lighten the soap color you can use less carrot purée. There’s fifty grams, or three Tablespoons, is in the original recipe. You could instead use just one or two Tablespoons and get the color of bars that you see below. If you do opt to use less, then replace the missing Tablespoon(s) of with water. The total amount in weight of both purée and water for this recipe is 150g (5.29oz). Make sure that whatever adjustments you make they still add up to that.
All three shades that I’ve made are lovely in their own right. I’m thinking now that you could potentially layer up bars with different shades of carrot soap for an ombre effect. How pretty would that be?
Natural Carrot Soap Recipe
- Stainless steel pan for melting the solid oils
- A large bowl for measuring the liquid oils into
- Heat-proof jug for the lye-solution
- 64 g Sodium hydroxide 2.27 oz
- 100 g Distilled water 3.5 oz
- 50 g Carrot purée 3 Tbsp / 1.76oz
Add after Trace
- 9 g May Chang (Litsea cubeba) Essential oil Optional / 2 tsp / 0.32oz
- 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.