Homemade Castile Soap

The soap that results from this recipe is certainly nicer than anything you can buy at the grocery store, and it holds its own against fancy specialty castile soaps, depending on what extras you add to it.  It lathers very nicely, and your skin is left feeling clean, but not dried out.  Give it a try!  It makes for a fun Saturday morning.


48 ounces of Crisco (the big 3 lb can)
21 ounces of cheapo olive oil (canola or soybean will also work)
18 ounces of coconut oil
28 ounces of cold water
12 ounces of lye crystals

Other items needed:

Food scale for solids
Safety goggles, or sunglasses if you'd rather look cool and rubber gloves
Measuring cup for liquids
Cheapo digital candy thermometer
Large glass or stainless steel bowl
Large stockpot
Wooden spoon, electric hand mixer or stick blender for mixing
Essential or scented oils, tea leaves, oatmeal, ground walnut shells, etc (all optional)
Lasagna pan, Tupperware containers—anything to serve as a mold, lined with wax paper


To Do It To It:

Pre-measure the oils, the water and the lye.  Be very careful with the lye—it is harsh, caustic stuff.  Combine oils in the big pot and gently warm them on the stove until all the solids have liquefied.  

Put the cold water in the glass bowl and slowly add the lye crystals--this will set off a chemical reaction—the lye water gets really hot and will give off some evil fumes for about a minute.  It may also splash, which would burn you, so it’s not silly to wear gloves and/or glasses.  The bowl will get really hot.  

Now you play a game:  the lye water and the oils need to be pretty close in temperature before you combine them, and that temperature is ideally 100 degrees F, although if you can manage to get each one between 100-105 degrees you’ll still be OK.  This means the lye water needs to cool down, and the oils need to warm up.  It takes some time, and it’s boring.  I use a cheap digital food thermometer and check each one every few minutes. 

When both mixtures have reached the magic temperature, slowly add the lye water to the oils, and keep the burner on very low to maintain your 100 degree temperature.  Begin your mixing!  Stir constantly until the mixture reaches the “trace” stage, meaning when you drag your mixing tool across the liquid, it leaves a little trail behind it.  This’ll make sense when you see it.  It’ll be the consistency of pre-refrigerator instant pudding mix.  By hand, this could take an hour.  With an electric hand mixer, it’s around 15-20 minutes, and with an immersion blender it could be as little as 3-5 minutes.  Don’t worry about overmixing—the trouble lies in undermixing. 

When you get to the trace stage, you can add any scents or coloring agents, or any extras like oatmeal for scrubbiness, and mix them in thoroughly.  Add as much or as little as you like, though I've found it's neccessary to add more scent than you'd think you need.  The smell gets more subtle as the soap cures.

Pour the soap into your mold, cover with some wax paper, and keep the soap in a warm, dry place for about a week.  If your house is chilly, you may want to wrap it in some towels or a blanket to allow the soap to cool down very very slowly.  If your house is really hot, you can just keep it in the cold oven for a while until it’s cool and then set it out for the rest of the week where you’ll know the air stays relatively dry (not the bathroom, for example). 

In a week, take the giant bar of soap out of the mold and cut it into shapes.  Take your shards and shavings from cutting and make a soap ball so you don't waste any soap!   If there’s a white powdery stuff on top, scrape or grate it off.  It's generally a good idea to let it sit for another week to get nice and hard. 

That’s that!  Usually good results, and you can make all sorts of different varieties depending on what you add at the trace stage.  It feels great when it’s just plain, too, though—Brian likes the plain best, and even washes his hair with it.