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How to use butterfly pea flowers, a natural and plant-based ingredient, to create baby blue soap bars. They’re truly beautiful! Use this blue butterfly pea flower soap recipe to make them yourself at home using an easy soap base.
This is a simple melt and pour soap recipe that gives you stunning light blue soap bars using a natural colorant. It’s easy too since you’ll be working with a pre-made soap base and just a couple of other ingredients. Other things it has going for it is that it’s quick to make, has very little prep, and you don’t have to worry about handling lye. In as little as forty minutes, you can have soap made that you can even use on the actual day!
The magic ingredient in this blue soap recipe is butterfly pea flowers. These are edible flowers from the clitoria ternatea plant from south-east Asia. In their homeland, they’re used as a natural food colorant and in Ayurvedic medicine. More recently they’ve been introduced to the west where you can sometimes find them used in drinks at trendy bars. Though they don’t tend to be sold fresh, they’re relatively easy to come by in dried form.
The stunning natural color that you get from butterfly pea flowers is a wonder to behold. If you’ve had experience with these edible flowers before, it’s likely been from an electric blue drink. Or perhaps a gorgeous mulberry shade! If you add an acid such as lime juice to blue drinks colored with butterfly pea flowers they change color. From blue to shades of purple to magenta right before your eyes! The blue color is the most amazing though! So magical, in fact, that many a soapmaker has tried to use this natural colorant to color handmade soap. Unfortunately, most of their results have ended up turning beige or no color at all.
Butterfly Pea Flowers as a Natural Soap Colorant
That’s certainly the case when using butterfly pea flowers in any cold process soap recipe. It’s not the pH that seems to eliminate the color, but I suspect a reaction with free-floating lye. I understand that you can add it to hot process soap (typically made in a slow cooker) with some success. You’d add it after the cook to avoid having it come into contact with ley. However, the initial blue color that you get fades into a gray-blue a bit reminiscent of woad soap.
However, you can add butterfly pea flower extract to pre-made soap bases, called melt and pour soap, with great success! Melt and pour soap is not true soap but usually has some element of soap in its ingredients. Though it’s not 100% natural, it’s skin-safe, easy to work with. It’s also a way to make soap without handling lye or lye solution.
Melt and Pour Soap is Easy to Use
Most from-scratch soapmakers (either CP or HP) don’t work with melt and pour at all. For me, it’s a guilty little pleasure since it’s so easy to work with! So quick and easy that you can make several small batches of soap in an hour or so. So satisfying and entertaining and the clean-up is negligible too.
To use melt and pour soap, you first chop it into small blocks. Then you melt it, add extra ingredients if you choose, and pour it into molds. Melt and pour soap is the type of soap that you can get as soap gift kits during the holidays. It’s safe for children to use too!
There’s one main thing to consider, though. Melt and pour soap bases are not natural. They are made of both soap and synthetic ingredients such as SLS (sodium lauryl sulfate). So if you’re after making all-natural blue soap, stick to making this indigo soap recipe. For a blue-grey soap, you can use this Cambrian blue clay soap. Both are cold-process soap recipes that you make from scratch.
Butterfly Pea Flowers as a Natural Colorant
To extract the blue color from butterfly pea flowers, you first need to infuse the dried flowers in water. This can be a tricky area since you’re not really supposed to add water to melt and pour soap. The reason is that it can cause glycerine dew to form on the bars after they’ve hardened. Tiny droplets of moisture that are harmless but wet and sometimes sticky due to their being vegetable glycerin. I was inspired by another recipe that uses water to try using butterfly pea flower tea. Fortunately, it worked!
I think that the trick is to reduce the amount of water in the melt and pour soap. You can do this by heating the melt and pour soap to encourage some of the water to evaporate out. I’ve included that step in the instructions below.
One thing that you’ll also notice when working with butterfly pea flower tea in soap is that it can start out a vivid blue but change to light blue. That’s because the extract is a true blue in a neutral pH substance, like water. It changes to light blue in a really alkaline environment, like soap base. No matter how much butterfly pea flower tea you add, you’ll only ever get light blue. The color of the soap will also fade over time, especially if the soap is stored in a bright place. Keep your soaps in a dark cupboard for best color preservation.
Further Tips Before Making This Recipe
Butterfly pea flowers need a tropical to sub-tropical environment to grow and are native to equatorial parts of Asia. It’s been introduced elsewhere though and where it grows, you’ll see it as a creeping vine with deep blue flowers. If you’re not able to grow or buy it fresh, you’ll need to buy it dried. Keep an eye out on the ingredients though. If you buy butterfly flower tea it will often be mixed with lemongrass for flavor. What you want should have only one ingredient listed: “pure dried butterfly pea flower”. You can sometimes find it as blue butterfly pea powder, but whole flowers are probably better for this project.
Another thing is that there are A LOT of different types of melt and pour soap bases. They come in two colors though — white or clear — and you’ll need an opaque white base for this recipe. The type that I used had added shea butter in the recipe but honestly, you can use any type. I did try butterfly pea flower tea in a clear soap base but wasn’t impressed enough to want to share it.
Butterfly Pea Flower Soap Recipe
- Heat-proof jug, jar, or bowl
- Prepare the butterfly pea flower tea at least half an hour in advance. I made mine the day before and refrigerated it. Place three butterfly pea flowers in a cup and pour over two Tablespoons of scalding hot water. The water will turn blue immediately but will intensify over the next five minutes or longer.
- Leave the tea to cool on the counter and pull the flower petals from the water before using. Squeeze as much liquid from the flowers as you can. If you make the tea in advance, you can refrigerate it for up to three days.
- Measure and then roughly cut the soap base into 1" cubes and place them in a heat-proof container.
- Melt the soap base in the microwave (or using a double boiler) until it's fully melted. Stir every minute or so with a spoon or silicone spatula. In the microwave, my base took about five minutes to melt completely.
- When fully melted, place the container of soap base on the counter and stir in a Tablespoon or less butterfly pea flower tea. Stir well.
- Place the soap mixture back in the microwave and heat for a further five minutes, stirring every minute or so. If you're using a double-boiler, leave the soap to heat through for 25-30 minutes. This step is to help encourage water to evaporate from the soap base.
- Place the melted blue soap base on the counter and cool to 140F (60C) before adding the essential oil and stirring it in thoroughly.
- Stray the mold(s) with the alcohol and pour the soap into the mold(s) immediately after stirring in the essential oil. If you see bubbles on the surface, spritz them lightly with alcohol.
- Although optional, you can lightly decorate the top of the soap with dried butterfly pea flowers. You can either lie them on the soap's surface before it hardens or add them later*.
- Allow the soap to cool and harden for several hours before popping it out of the mold(s)*. Don't be tempted to put the molds in the fridge since that can cause issues with glycerin dew as well. Cut loaves into bars of whatever size you'd like and use the soap immediately if you like. Pre-made soap bases do not need to be cured like from-scratch soap recipes.
- Store these soaps in an airtight container immediately after they've cooled. This will help reduce the chances of the bars developing glycerin dew. Also, keep them in a dark place to minimize color fading. In bright places, the soap's color will begin to fade over the course of a week or two.
More Ideas for Naturally Coloring Handmade Soap
This butterfly pea flower soap recipe is as beautiful as it is easy to make! If you’ve had your appetite whetted for more, there are PLENTY of natural soap recipes for you to explore on Lovely Greens. Here are a few to get you started:
- Indigo Soap Recipe (natural blue soap)
- How to Make Old Soap Bars New Again
- Calendula Infused-Oil Soap Recipe (natural yellow soap)
- Comprehensive List of Natural Soap Colorants