How to make bar soap – the basics

Have your always wanted to make your own homemade soap, but have been afraid to try? Here are some basic steps, an example recipe to follow, as well as all the resources you need to make your own!

Making your own soap can be fun, rewarding, allergy-friendly and makes great gifts. I say allergy-friendly because you can choose exactly what to put in. I’ve had friends with skin-conditions like psoriasis test my scent-free soaps and then rave and ask for more.

Making your own can also be a great addition to your community! If you love making soap but hate darning socks, perhaps you can swap soaps for freshly mended socks with a more craft-inclined neighbor! Self-sufficiency should not be about anyone person learning all the tricks of the trade perfectly, but a whole community building the skills they need together.

You will be better at somethings, while your neighbors, family, and friends will excel at other things. Embrace it and share, it is much more fun! Bringing skills back to the community saves money as well, as you need less cash to buy services from outside.

The sustainability of bar soap

But wait! This is not only about saving money. This is also about keeping things local, learning skills and not littering the world in plastic. Just think about it, all those bottles of liquid soap need a container to be shipped in, and most of the time, that is plastic. A bar of soap is more compact, taking up less shipping space for the same amount of washing value, and can easily be wrapped in sustainable and reusable paper or fabric.

They are not riddled with germs as many people seem to believe, and even if they were, the action of washing our hands (with soap!) would still kill or rinse off the majority of them. Even if it is just as your hand soap of choice in the bathroom, I encourage you to give bar soap a chance. And if bar soap really isn’t your jam, it is possible to grate it, boil it in water until you achieve the desired consistency, and pour that into a beautiful, reusable soap dispenser.

Yes, I know that you can probably get a really cheap soap for less than it costs to make your own. I will admit that freely. But making your own gives you a nice bar of soap that does not drain your skin of moisture and leaves your hands dry. You can also choose to omit rainforest-killing palm oil from your own soap.

The bare-bones

At the heart of it, soap is a chemical reaction between fats and lye. Lye breaks down the fat into free fatty acid chains and glycerin, and different fats will give you soap with different qualities. For fanciness or added luxury, you can add fragrances, clays, flower petals, colors or whatever else you want, but at the very basic, it is lye and fat that makes soap.

A great place to start if you like very specific recipes is Brambleberry’s affiliate site (not a sponsor), The Soap Queen, which features a whole bunch of recipes to get you started. Of course, they heavily advertise their own wares, which I have no experience with, as shipping to Norway would cost me a small fortune.

Lye calculators, an ecofrugal best friend

If you’re more like me and like to experiment or use what you have, then the Sage lye calculator is my favorite and go-to for calculating the lye-to-fat ratio. Because different fats contain different numbers of molecules by weight, you need to adjust your lye accordingly.

A lye calculator helps you with this, and also gives you basic instructions. I really like this method of making soap. Because I can use up any leftovers I have from different projects.

Often, I will make the recipe as I work. If I know I only have a little olive oil left. I will weigh it, write it down, and weigh all the other oils I’m using. Then, with my real numbers in hand, I go to the lye calculator and add in exactly how much of each oil I have.

Not only does this help me use up small bits and pieces, but it also means I don’t have to be super-accurate with the weighing of the oils! I simply adjust my lye according to what I really have.

A note on lye

Lye (NaOH, or sodium hydroxide), and especially the concentrations we work at in soapmaking, are very corrosive and will react exothermally (create heat) when mixed with water. Keep out of the reach of children and pets. Make sure you protect your eyes in case of splashes and make sure you always have a source of running water nearby. If you have a good kitchen fan, dissolve the lye in water there. If not, do it outside using stainless steel or plastic utensils.

Don’t try to neutralize spills with vinegar or anything like that. If you spill some on yourself, just go straight to the sink or in the shower and apply lots of water. You must continue rinsing with water until your skin no longer feels soapy (the lye is transforming the fats in your skin into soap). I’ve not yet had a mishap in my kitchen, but you should still take basic precautions, of which protecting your eyes and access to running water are the most important. You should also work under a strong kitchen fan or even outside, as lye will sting your nose. Do not stick your nose into a fresh bowl of lye water.

Ecofrugal tip: Homemade soap makes fantastic gifts!

Kristine’s unscented basic soap

This is the one I make for all my friends with skin conditions. It is also a great base to add any scent you want!

You will need:

  • Stainless steel or plastic bowl
  • Stainless steel or plastic spoon
  • Spatula
  • Medium-sized pot
  • Immersion blender
  • Scale
  • Thermometer
  • Mold (old milk cartons, ice cream cartons, or silicone soap molds)
  • 200 g (7 oz) Shea butter
  • 320 g (11.3 oz) olive oil
  • 200 g (7 oz) coconut oil
  • 200 g (7 oz) sunflower oil
  • 126 g (4.4 oz) lye/NaOH
  • 250 mL (1 cup) cold water
  • Optional: Essential oils or other scents, if using (should not be more than 2 % of the total oils, or it might create irritation and reactions)
  • Ice bath or sink with cold water, if impatient


Under a kitchen fan on full speed or outside, pour your lye pellets into the water and stir slowly until everything is dissolved. This is an exothermal reaction. It will heat itself.

Leave under the fan while you combine all your fats in the medium pot and melt everything on low heat. Use your thermometer to get the fats up to 45-55 C (115-130 F). Check the temperature of your lye mixture. If it still too warm, wait or place in an ice bath while you mix slowly until you reach the desired temperature.

Once both mixtures are at 45-55 C (115-130 F), take the spoon out of the bowl of lye (place in the sink with running water or in a large body of water). Place your immersion blender in the fat mixture and tap it a couple of times under the surface to get rid of any bubbles. It is important to make sure your pot is of such a size that the fats are at least an inch or more over the head of your immersion blender.

With the immersion blender ready, pour lye mixture in a thin, steady stream with one hand into the pot while you gently blitz to incorporate it. Avoid getting large sections of pure lye water as it might create a grainy and uneven result.

Continue until you’ve transferred all the lye into the mixture, which should turn milky. Continue using the immersion blender all over the pot (but careful not to lift it out of the mixture), until your mixture changes from a runny liquid to a thicker consistency. Maybe like a good liquid soap or shampoo. If you see no clear layer of oil at this thickness/stage, you have reached trace, and you are ready to pour into your mold.

When you reach trace is also the point to add fragrance, clays or anything else you might want to add. If you add it before, the lye will likely destroy it.

As a general rule, the thicker your mixture, the more lye has reacted with the oils already. It might be tempting to go all the way to thick trace and get more of a pudding consistency. There will be nothing wrong with that, but it will be much harder to pour it into molds without trapping air bubbles inside.

After 48 hours, inspect your soap. Is it still soft? It it is soft, leave another 48 hours and check again. When it is hard, remove it from the mold and cut it into soap-sized pieces. Leave to cure further for 4-6 weeks.

Best of luck!

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