Starry Night Cold Process Soap

This year my 10yo daughter started making soap with hopes of running her own soap business "froggy soaps". We learned soapmaking together for a few batches, and now I just watch and keep the shelves stocked. Recently I saw the soapmaking contest on the instructables page and asked if she wanted to enter. She came back with this idea and made it, while I documented and helped with the write up.

Cold process soap is easy to make and you can complete it quickly, but once its demolded you will need to allow the soap to cure for 4-6 weeks on a shelf before it is useable (the lye mixture is very alkaline, and the soapmaking process will result in a netural pH soap; but using it before it gets there may not be kind to your skin, which is the opposite of what we want with a skin care product like soap).

13.11oz Distilled water

5.30oz Lye (food grade NaOH)

19oz Coconut oil (warmed to 92F)

13oz Olive Oil

2.5oz Avocado Oil

1 tablespoon food grade activated charcoal powder

[optional] 1oz fragrance oil (essential oil or fragrance oil of your choice)

Two glass measuring cups (4 cup and 2 cup).

Lye safe cup for measuring lye prior to mixing (can use glass or a disposable plastic/paper cup)

Metal spoon (for mixing water and lye).

Silicone mixing/scraping spatula (for moving and mixing soap into molds).

Wand mixer (any cheap one will do, probably not a good idea to use soap tools for food later).

A well ventilated area to work in as well as eye protection, gloves, and a mask.

Soap molds (we used two loaf molds that hold around 42 oz each, but any kind will do).

Some white colored soap that you can break down into small particles.

[optional] some little accents to add to the top of the soap (we used little white soap moons)

Soap is created by combining oils with an alkaline solution triggering the saponification process resulting in soap.

The alkaline solution for this recipe will be water and lye and that liquid is hazardous. We should treat it with respect and protect ourselves by wearing gloves and eye/respiratory protection when handling it.

Once the soap is created the pH begins to neutralize and after the curing time the pH will be neutral (you can use an inexpensive pH test strip to confirm before lathering up with your new soap).

Before the ingredients start getting mixed you'll want to have your molds ready to receive the soap, and shave a few bars of any solid white soap into small particles to add to the soap in the final steps (they will become the stars in the night), we used a cheese grater to make ours. The amount you'll need will be a reflection of how many stars you want in your bars. We added about 20% of the soap volume for this recipe.

Once the prep is done we can start off by mixing the water and lye together, the time it takes to fully dissolve can be long depending on the temperature and how much you're mixing it, so best to get it started first.

*always add lye to water* never the other way around.

Put on your gloves, mask and eye protection, if you get some of the mixture on your skin just wash it off with soap and water, but you'll want to wear protection to keep sensitive areas like your eyes safe at all times. If you're smelling the lye water as you mix, you might want to step back to avoid inhaling the fumes.

Work in a well ventilated area (we usually go outside) and mix up the water in the smaller container with the metal spoon and add the lye while stirring.

You should see the water become cloudy and temperature increase as the lye dissolves into the water.

stir to make sure there isn't a solid forming on the bottom (if it does, just keep stirring until it's broken up) then set it aside as we move to the second step.

Measure out your oils into the 4 cup glass. Some oils like coconut are solid at lower temperatures, you'll need them liquid for this process. You can put the coconut oil jar into hot water or if it's in a microwave-safe container you can microwave it as well.

Once all of the oils are liquid and in the cup add the lye water you made in step 1 (the water should be clear by now without any solid lye remaining) and stir. You should see the Saponification process starting immediately as the oils become cloudy and start to become soap. Once the liquids are mixed you'll want to switch to the wand mixer to speed things up.

As you mix with the blender you'll notice the fluid becoming opaque and thicker with time. "Trace" is a term used to refer the stage of emulsification where the oils will no longer separate from the other liquids. This is vital as if there are still unblended oils when you pour your soap it may cause the soap to separate or not solidify properly.

Trace can be visualized by not seeing lines of oils when you stir, as the trace gets thicker you can lift your mixing tool out of the mix and watch the soap drip off the tool: Light trace will form strings that will be visible on the surface as they fall, while heavy trace will hold its form looking like a pudding-like texture. You won't be able to see it but you'll also feel the mix getting thicker as you stir.

We need a thick trace because we will be dropping in the 'stars' and if the trace isn't thick they won't be suspended and will all fall to the bottom of the mold. (which might be cool too but not what we're going for here).

Now that we have a nice and thick soap mixture we're going to add the activated charcoal powder. Once it's a finished soap it will not stain your hand, but a little goes a long way, one tablespoon was enough to dye the mixture black for us.

Once it's mixed in you can add an (optional) ounce of fragrance oil. You can go natural with an essential oil or your favorite scent of a fragrance oil (make sure they are Phthalate-free if you use one).

Finally we will add the "stars" to the night soap, so sprinkle in the white chunks and stir them up until your night is as starry as you want it to be. (the black soap will coat them in this step but once we cut the soap or use it to wash with the white bits will be exposed again).

Time to pour it into the molds.

Your soap is going to be pretty chunky by now so get a scraper and help it into the molds you're using.

This is optional but we added a little moon accent from a previously made mold that made a long crescent shape that we cut to size and placed about an inch apart on the top of the soap.

Once you're happy with how it looks cover the molds with plastic wrap (if it touches the wet soap don't worry it will come off easily later). Then cover the soaps with a few towels. The soap will heat itself up a bit as the saponification process continues, but what were trying to protect it from is rapid temperature changes. If the soap cools too quickly you may get some white color changes on the exposed surface. If you do it's ok, it's not bad soap and you can shave it off if it's unsightly.

Now allow your soap to sleep for 24 hours. We'll come back tomorrow to pull it out and cut it into bars.

Remove your soap from the mold carefully, it should be pretty hard by now but it's still soft enough to deform if you press hard on it. You can use a cutting jig, or just grab a kitchen knife and slice the loaf into bars.

Take the bars and place them on shelf for 4-6 weeks to allow them to 'cure'. During this time they will loose some of their water content, become harder, and the pH will neutralize to become the wonderful soap we've been working for.

After that enjoy your soap, they work great and will brighten your day when you see the fancy soap on your counter, making extra is always a good idea too as they make a great gift.