How to make your own bars of soap

That should make a nice castile soap. Big fan of Kirks Coco Castile myself.

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/pedant Castile soap is technically all saponified olive oil and takes months to cure to the point where you can use it; it’s very gentle to your skin, but the texture of the lather (fine, almost slimy) cam be offputting. Many soap making people use other oils/fats in addition to olive oil so it cures faster, makes better lather etc. My first world problem is that the essential oils I add to my soap for fragrance disappear by the time I am ready to use it.

eta: Measuring the lye so it’s in the correct proportions to your fats and oils is important (hint: get a good scale). You can find lye calculators online that make it easy. There are also websites that sell fats and oils for soapmaking, and address a lot of common problems.

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What MadLibrarian said. Also, be aware that if you screw up badly enough, the lye will eat your face.

Maybe start with melt-and-pour soap instead.

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As can the density of the label:
image

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Use more liquidy fats (e.g. canola and corn oils instead of palm and coconut oils), and at least mostly potassium hydroxide instead of sodium hydroxide. The soap will end up liquidy.

Most of the “make your own liquid soap” stuff I found online was just suggesting buying a bar of hard soap and chucking it in the blender with some water. Sigh.

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Make sure you use 100% lye. A lot of drain openers have other stuff in them too.

If you do hot process, you can use it the next day. Basically you cook the soap until saponification is complete. Put in mold, cut when cool, use.

I cook a lot of bacon, so I end up with a lot of bacon fat - more than I can use cooking. So I make soap out of it. I also throw some coffee in there - save a couple of used espresso pucks. Finally, throw some salt in the soap at the end of the cook - this’ll help it harden so that it doesn’t wash away in your first shower.

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Breakfast-scented soap!

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Unfortunately, the bacon smell doesn’t survive the saponification. I really wish it did.

I’ve tried hops in it too, same thing - just doesn’t survive the process.

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@MadLibrarian

I had the good fortune to try this at the Tumble In outside Marfa, Texas. It’s especially good for Seborrhoeic dermatitis, which affects the crevices between my cheeks and nostrils, my eyebrows, and scalp:

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If this will work, then I might as well create an account on Etsy and sell my own bar soap for extra income. :wink:

I’ve made my own soap from saved animal fat and lye (not from the clinic you sick bastards!)

There are sites out there that have calculation tables for the type of fat you’re using so you can slightly “overfat” your soap, to make sure you fully consume the lye during the process and end up with non-caustic soap.

Made a batch of beef tallow/coconut oil lavender soap for my wife last christmas. Turned out pretty well if I do say so myself.

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What percentage to potassium hydroxide to overall liquid?

If you’re using the soap to wash dishes, then having a bit of excess lye is fine, because it will react with the fat on your pans to make yet more soap.
Given the chemicals involved, I think I’d prefer to use home made soap on things like dishes, rather than my face.

You beat me to it. LOL :smiley:

The ratios of potassium or sodium hydroxide to oil can vary considerably depending on what oils you’re using - the molar masses of oils can be very different. A mass ratio of lye to coconut oil, used unaltered with a mix of canola and corn oil, would leave a tremendous amount of unreacted lye in with the soap - it would be very caustic and unfit to use on skin.

There are quite good soap calculators, I’d use one of them.

I worked in a huge cafeteria kitchen for a little while - their big dishwasher, when running at full speed, took about ten people to operate. Mostly I was handwashing the cooking dishes, but at the end of the lunch rush I was pulled from that duty and worked on the disassembly line putting the eating dishes through the big dishwasher.

That machine used pure lye, which came in 20 kg or so bags, as its detergent. When someone accidentally punctured a bag of dish detergent in the storage room, the cleanup was a pretty involved operation. After sweeping up as much of it as we could, we mopped and mopped the area with vinegar. Probably used a couple of gallons of vinegar (they also went through so much white vinegar they didn’t bother buying it in containers - a tanker truck came every couple of weeks and filled up the tank by the loading dock)

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Pedro, is that you? :slight_smile:

(I sometimes get very nice soap from a friend who does the same thing.)

Keeps the fat out of the drains, which helps control the local municipal budget.

You really shouldn’t have any lye left. But if you do, don’t use it on aluminum dishes.

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Isn’t that just a dumpster dive behind the clinic?

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It’s really not that hard if you’re paying attention and taking all the recommended precautions.

You have to really screw up to make caustic soap.

If you use a lye calculator, allow for a generous superfat percentage, and carefully weigh the lye out, your end product will be safe.

There can be a likelihood of having an undissolved lye clump in the soap, but that’s why the lye should be fully dissolved in water first.
Also, using a cheap immersion blender to mix the lye solution thoroughly further prevents lye spots from happening.

A bar can still be a little harsh if for whatever reason there’s still some unreacted lye after all the fat’s been saponified, but it’s not eat your face off bad, plus allowing it time to sit and cure will mellow it out by having it react with the carbon dioxide in the air to neutralize out into soda ash.

Some people use pH strips, but the tongue test works too.
Touch the tip of your tongue to a bar. If it tastes like soap, you’re good, but if you get a zap, it still needs time to cure.

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That’s an excellent rundown of the caustic soap problem. I was referring to a less subtle issue: working with high molarity sodium hydroxide is inherently dangerous, because lye will eat your face. Drop the lye pitcher at the wrong time, lye splashes, chemical burns, ow ow ow. It’s a disproportionally risky chemical hazard to work with in pursuit of a product that isn’t worth very much.

One can approach melt and pour soap casually. Saponification, though–when we’re dealing with quantities large enough to end up with full-sized bars of soap–you have to be pretty careful with.

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