Let’s face it: commercially produced soaps aren’t all that interesting. They’ll clean you off, but they don’t have much character, and usually they don’t even feel that great on the body. Making soap at home is not as intimidating as it can seem—it’s actually pretty simple, and people have been doing it for hundreds of years. You’ll save money, and your bars of soaps will be all a little different, with lots of character.
Before you get started, it’s helpful to understand what soap actually is— the byproduct of a simple chemical reaction, between oils and lye.
The wide range of different soaps made at home and commercially is produced by adding various ingredients in different measures to the reaction. As you get more comfortable with saponification (the process of making soap), you can play around with adding different herbs, spices, and flowers.
There are several ways to make soap: cold process, hot process, and melt and pour (the easiest way, this one’s good to try with kids). Traditionally, lye (sodium hydroxide) was leached from ashes, and oils came from animal fat; today, you can find these products in most health and beauty stores, or on the internet.
Cold Process Soap Making
Cold process saponification involves combining lye and water with the oils or fats away from a heat source—you heat the two compounds separately, then turn off the heat and combine them when they’re at the same temperature. Vigorous mixing encourages the chemical reaction (see the castile soap recipe below for more detailed instruction), and you end up with a thick textured mix, called trace, which needs to cool and set in a mold for at least a day.
Hot Process Soap Making
Hot process saponification, as you might have guessed, is facilitated by constant heat. You gently heat the oils in a large steel pot on the stove, then add lye water (very slowly, to avoid potentially burning yourself with the caustic) to the just-melted oils, while keeping the heat on. The trace stage here happens fast—heat’s a handy chemical facilitator. Stirring the mix of oil and “curds” of soap is crucial, or else the resulting chemical compound is not going to be pretty. If you keep the heat too high and/or don’t stir, you run the risk of burning the soap into the pot, ruining the pot and smelling up your kitchen most foully. After around twenty minutes of stirring over low heat, little bubbles will come to the surface; turn the heat off and let the pot cool for ten to fifteen minutes, until the bubbles stop rising to the surface. This slows the reaction down, a necessary pause. Reheat the pot and keep stirring until the real magic happens: the three separate layers of chemicals (essentially, water, lye, and oil) eventually unite into a more solid, gelatinous substance. A little more heat will evaporate excess water; too much heat here will dry the soap out. Then you add any essential oils or fragrances, and scoop the mass into a mold to cool. Unlike cold process soap, hot process soap is ready to cut and use as soon as it’s cooled down; the settling step is not necessary. (Alternate method: use a crockpot instead of the stove top—this takes longer, but the resulting soap can be a little smoother in texture. We’ve got a crockpot hot process recipe later on in this article).
Melt and Pour Soap Making
If either of those processes sounds overwhelming, try a melt and pour recipe first. The melt and pour method takes a readymade base block of soap and melts it down to liquid form, so you can some fragrances/spices/flowers before resetting it. Base soap blocks can be found in most health and beauty stores, and on the internet; one pound of melt and pour soap will give you about three or four bars of soap, depending on the size of your mold. We’ve got a recipe for melt and pour soap at the end of this article.
Here’s a simple recipe for cold process castile soap (castile refers to the Castile region of eastern Spain, where the soap was first made, in the 13th century).
- 20 oz of olive oil
- 5 oz coconut oil
- 8 oz cold water
- 3.3 oz of lye crystals
- (also caustic soda, look for it in the grocery store)
- 1 oz essential oil, for fragrance
Some purists prefer to make this soap with olive oil, as it was made originally; olive oil takes much longer to firm up, so we’ve adjusted by adding other oils. This recipe yields six bars of soap.
You’ll also need a large jar or bucket for mixing, a strong plastic spoon, a sturdy plastic or glass container (for the mold), a six-inch cutting knife, a stainless steel pan, and two candy thermometers. We recommend using protective eyewear, a mask, and rubber gloves (lye is a caustic). If you’ve got your own soap mold, so much the better.
- Wearing your protective gear, pour the water into a big glass jar or plastic bucket. Slowly pour in the lye, stirring with the spoon until it’s dissolved. The lye will heat the water; let this mix cool until the necessary temperature (see step 3).
- Combine the oils (excepting the essential oil) in the steel pan, and heat them gently over a low heat.
- Put one candy thermometer in the lye mix and one in the oils. When they both reach 110° f (43c), turn off the heat and slowly pour the lye into the oil. Never pour oil into lye: caustic soda crystals can splash out and burn your skin.
- Now it’s time to stir the mixture, with either a stick blender, a strong spoon, or a whisk. Stick blenders are not a common household item, but they’ll greatly reduce this part of the saponification process. By hand, you could be mixing for an hour until the soap thickens to the right consistency, a custardy texture—that’s the trace.
- Once you’ve got a workable trace, add in the essential oil (and natural coloring, if you like).
- Pour the soap into the mold and smooth it with a spatula. Leave it to set for 24 hours in a warm place, preferably wrapped in a towel, until the soap hardens. You want it to cool gently, for a smoother texture.
- Once it’s hardened, take the soap out of the mold and let the block air out for a day or so before cutting it with a sharp six-inch knife into bars. At this point, the soap could still be caustic; it’s wise to wear gloves for the first 48 hours of the process. After that, it’s ready to use.
Some folks like to roll their freshly cured, still malleable blocks of castile soap in lavender or calendula petals.
Ready for more..?
Here’s another cold process recipe…
15 oz sunflower oil
30 oz coconut oil
35 oz olive oil
5 oz Shea butter
18 oz cucumber juice
19 oz water
14.1 oz lye
In a blender or juicer, grind up enough cucumber for 18 ounces of juice. Set this aside.
Go through the cold process, as described earlier, with the other ingredients. Once you’ve got a good trace, add in the cucumber juice; this will give the soap color and a light, fresh scent. Let the soap set and harden, cut it up, enjoy.
And one more…
Pumpkin spice soap
16 oz olive oil (53%)
8 oz coconut oil (27%)
3 oz sunflower oil (10%)
3 oz cocoa butter (10%)
4.19 oz lye
8 oz water
2 oz canned pumpkin
1 tsp vanilla
20-30 drops of clove essential oil
Again, go through the cold process to the trace stage (“trace” refers to the texture here—you can trace a line through the mix and it will slowly fill in).
Add in the pumpkin here, stirring well.
Then transfer a third of the batter to a small plastic container; to this bit, add the vanilla and the essential oil.
Pour half of the just pumpkin batter into the mold, then pour in the vanilla spice layer, then the rest of the pumpkin. This soap likes to set for a solid two days (pumpkin’s pretty mushy).
Basic hot process soap recipe, in the crockpot
26 oz olive oil
6 oz coconut oil
3 oz. castor oil
4.75 oz. lye
12 oz. water
1 oz fragrance oil—lemon, peppermint, almond, whatever you like
- Set the crockpot to high, add the coconut oil.
- Mix the water and lye in a separate container.
- When the coconut oil has melted, turn down the crockpot to low and add the other oils.
- Slowly pour in the lye water, stirring all the time. Keep stirring until you reach the trace stage, then let the mix continue heating for another 30-45 minutes, on low heat. You can do a tongue test to see if the lye is dissolved: if the trace feels like soap, put a tiny bit on your tongue. If you feel a zap, it’s not ready. No zap means the lye is gone.
- Add in the fragrance oil, stirring well.
- Spoon the mixture into a soap mold (48 oz is a good size container for this project), let it cool.
- Cut into bars (this recipe yields about nine).
Melt and pour rose soap
- 4 oz melt and pour soap base
- 10 drops rose oil
- 1 drop of red food coloring (optional but pretty)
- Chop up the melt and pour base. In a double boiler, gently melt the chopped soap in water, without stirring. You can also melt the soap base in the microwave, in a heatproof bowl—heat it on full power for thirty seconds at a time, don’t overheat it.
- Once the soap base is melted down, turn off the heat (if you used a double boiler) and stir in the rose essential oil and food coloring. Mix well.
- Pour the mixture into a mold, tapping lightly to release any trapped air that might bubble up the surface. A spray with rubbing alcohol also helps cut down on surface bubbles. If you don’t like how the soap looks, or want to add more color or fragrance, just melt it down and try again.
- Let the soap cool until hard, cut it into bars.
- And lastly, we’ll point to a few good lye calculators, which are excellent references for home soap making. You can enter in the amount and kind of oil you’re using, and the calculators will supply the correct ratio of lye, and adjust for water weight. Visit HERE or HERE.