Multipurpose Soap Bar

This recipe is great if you have never made soap before. It is the same difficulty level as my basic soap bar for beginners, the only difference is that this soap bar has been formulated to be very hard, bubbly and cleansing. It’s perfect for household cleaning.

My other recipe is better suited for skincare – it is still bubbly, but it is softer and more moisturising. Whereas, this super cleansing and fragrance-free soap can be used for everything from washing dishes, laundry to bathing. Although I’ve recommended using my beginner soap bar recipe for your skincare, this soap bar is still perfectly safe to use on your skin – drying but safe.

Also, if you’re interested in attending one of my soap-making classes, you can sign-up to be notified about the next workshop here. No spam, I promise! Before we lather up, let me deal with a few FAQs

Frequently Asked Questions

Is lye or caustic soda toxic and dangerous? Why is it in natural soap?

Yes, caustic soda / lye is dangerous. By itself, it should never come into contact with skin, eyes or your lungs…nothing besides your kitchen and bathroom drains! This is why you need to be extra careful when working with it in the soap making process. Unfortunately, it is absolutely necessary to make soap. The reaction between lye and oil is what causes saponification (i.e. soap). Most importantly:

Once lye reacts with oil it results in glycerine and soap, which is natural and completely safe. So the reaction looks something like this:

Oil + Base (lye solution) —–> Glycerol + Salt (soap).

For those of you that don’t know, “lye” is the term referred to when caustic soda is mixed with water (it is a solution).

What safety precautions must I take?
  1. Wear long sleeves to prevent any chemical burns if the mixture splashes.
  2. Wear safety gloves.
  3. Wear protective eyewear to protect your eyes from possible splashes.
  4. Do not touch, inhale or ingest caustic soda. Store it far out of reach of children and pets.
  5. When you add caustic soda to water (step 2 in recipe):
    1. Do it slowly.
    2. Always add caustic soda to water, and never the other way around.
    3. Do this step outdoors away from children and pets.
    4. Do not inhale or let the lye fumes get into your eyes.
    5. Do not touch the lye solution.
    6. Do not leave the solution unattended, because it will look like water.
    7. Be careful when carrying the solution back indoors, because the bowl will be very hot. So wear oven mits to carry the hot bowl, if necessary. Be careful not to trip. Walk slowly.
    8. It is safe to bring the solution back indoors when it becomes clear, like water, and the fumes have dissipated.
  6. If your skin comes into contact with the lye or soap mixture:
    1. Don't panic.
    2. Immediately wash the area thoroughly with cold water.
    3. Then wipe the area with white vinegar to neutralize the lye.

      If you do touch it, you will first feel an itch, which then starts to feel like a burn. When you feel the itch, rinse with water, and then vinegar.

  7. Have white vinegar around at all times. It will neutralize the lye. Wipe counter tops or whatever the mixture touches with vinegar.
  8. Before washing your utensils with dish washing soap, first rinse them with water and then wipe with a cloth that is soaked in white vinegar, or rinse in a vinegar solution (just fill the sink with water and add about a cup of vinegar – rinse in there). Then wash with dish washing liquid as usual.
Can I use the same pots that I eat from to make soap, or should I have separate equipment for soap-making?

You can use the same pots and equipment to cook and to make soap, but you must ensure that you clean everything properly and that all your equipment is stainless steel. I personally don't have separate equipment for soap-making, and I use the same pots to make soap and soup. I do have a separate blender though. It is obviously ideal if you can afford to have separate equipment, but it's not absolutely necessary.

How you must wash all your equipment before cooking with it after soap-making:

  1. Rinse all your equipment thoroughly in cold water;
  2. Then rinse or wipe your equipment in a vinegar solution to neutralize any lye (eg. fill the sink halfway with water and add about 1-2 cups of vinegar, or wipe with a cloth that is soaked in white vinegar);
  3. Then you can wash your equipment with dish washing liquid as you would normally wash your dishes. Now your equipment is ready to use for cooking.

A special note about blenders: Some blenders are not completely sealed where the blade compartment is, and they allow food to get stuck behind the blade etc. If your blender is not properly sealed, DO NOT use the same blender for cooking and soap-making. You will get soap in your soup.

Why can't I just buy natural soap?

Well, of course you can. The only reason to make your own soap is to save cost and customise, especially if you want organic soap (just make sure you use organic oils and additives). Just be cautious and always read the ingredients when you buy, as many retail soaps include unwanted and unnatural additives. This soap recipe only uses what is absolutely required to make soap, nothing added. All the rest is up to you.


This makes just over one litre of soap, which is roughly 10 bars. That’s enough to last one person six months or more!

This recipe has been formulated to be used for household cleaning purposes. It is a hard & bubbly bar of soap that will leave no greasy residue on dishes, clothes etc. In other words, it is not moisturising at all. However, it is technically safe to use for skincare, but it may be drying. If you are looking for a bubbly soap bar that is a bit softer and moisturising for your skin, I recommend using my basic soap bar recipe instead.

Multipurpose Soap Bar

Prep Time: 30 minutes

Total Time: 30 minutes

Natural Cleaning

Multipurpose Soap Bar

A fragrance-free soap bar recipe which is ideal for beginners who have never made soap before. This soap recipe has been formulated to be used for household cleaning. With a 0% superfat, it is not suitable for skin care.


    For the Soap:
  • 330g Water (distilled water is best, but not necessary)
  • 164g Caustic Soda (you can find this at most hardwares)
  • 900g Coconut Oil
    Equipment & Tools:
  • Kitchen Scale
  • A heat-proof glass bowl for the water. Check that the bowl is microwave and dishwasher safe.
  • Large stainless steel pot for oils & water (minimum capacity: 2 litres)
  • Immersion blender, or electric two-prong whisk
  • Stainless steel spoon
  • Stainless steel chopping knife
  • Soap moulds for 1.5 litres of soap (ice-cream/ margarine containers work really well too)
  • White vinegar for cleaning any spills
  • A cloth soaked in white vinegar for cleaning


  1. Measure out the quantities exactly with a scale: This recipe is like chemistry. Unfortunately, there’s no compromise and you have to use a scale, and follow all instructions to a tee.
  2. Make the lye solution: Slowly add caustic soda to water in a glass mixing bowl (NOT the other way around). Do this in a well-ventilated area. Outdoors away from any pets is best . Do not inhale any of the fumes from the reaction. The solution will be murky and it will become hot, this is normal. This solution is known as lye.
  3. what is lye
  4. Start heating the oil: Heat the oil in a genuine stainless steel pot. Do not let it get to boiling point, this is way too hot. If the oil is too hot, your soap will flop and turn into a volcano. If you have a thermometer, the ideal temperature for the oil is 50°C. You should be able to touch the oil and not burn – not that I’m encouraging you to touch hot oil, this is just to give you an idea of what 50°C feels like. The oil is hot, but nowhere near boiling. While the oil is heating up, your lye solution will be cooling down. The lye should start looking more clear (less murky) with time. Make sure that all the caustic soda crystals are dissolved by stirring with a stainless steel spoon.
  5. how to make natural soap
  6. Combine lye with the oil: First switch the stove off. Once both the oil and lye solution are roughly the same temperature (approximately 50°C), add the lye mixture to the oil. Do not touch the lye mixture to determine the temperature please – you will suffer a chemical burn. Rather touch the side of the glass bowl, or use a thermometer. Once combined, start blending with an electric mixer or immersion blender. Mixing by hand can take hours! Again, please make sure that the stove is turned off at this point.
  7. how to reach trace in soap making
  8. Blend until you reach “trace”: Trace is basically the state when the soap mixture is ready to be transferred into your moulds. You know you’ve reached trace once the mixture has the texture of instant pudding. When drops of the mixture fall back into the pot and show a visible trace of themselves on the surface, this is trace. The droplets shouldn’t sink back in quickly, or disappear immediately. The time it takes to reach trace depends on your oil and the speed of your electric beater. It takes me about 5-10 minutes to reach trace with this recipe when using an immersion blender, and 10-15 minutes using a two-prong electric beater (the one in the image below). If my description has just confused you more, I do hope the picture helps!
  9. what does trace look like
  10. Add your additives (optional): If you’d like to add essential oils, fragrance oils, spices, herbs, clays, iron oxides or a few drops of liquid colouring – Now is the time. Don’t add too much, as you can upset the soap formula and end up with oily or crumbly soap. I’d recommend about 5-10ml of essential oils, 5ml of fragrance oils, and up to 2 tablespoons of herbs and powders. Since this soap is meant for household cleaning, you shouldn’t need to add any extra herbs or oils etc. But you might like to add a bit of fragrance.
  11. Transfer the soap mixture into your mould: I like to use empty ice-cream and margarine containers, because the plastic is thick enough not to melt, yet flexible enough to get the soap out easily once it hardens. Some people use proper wooden soap molds lined with wax paper, or even silicone baking molds. Do not use tin foil to line your moulds, and do not use your metal baking tins or Tupperware as moulds – you will destroy both the soap and the tins/ Tupperware.
  12. what material is safe for using as a soap mould
  13. Insulate your mould with a towel or blanket, and store in a warm and dark place overnight: I put the lids on my ice-cream/ margarine tubs, wrap the containers in towels for insulation and store in a cupboard overnight.
  14. Cut soap into bars after 24-48 hours: The soap is firm enough to remove from the mould, yet soft enough to be cut into bars. If you wait longer than 48 hours, it may be difficult to cut your soap, and it will crumble. Cut your soap with a stainless steel knife. It will be like the texture of a hard cheese. Do not use your soap at this point, it still needs to cure. If you use it, your skin might suffer from a chemical burn. The lye is still reacting with the oil, only once this process is complete (curing), then you can use your soap.
  15. simple easy homemade soap recipe for beginners
  16. Let your soap cure: Like good wine, good soap needs time to cure. The saponification process is still taking place, and your soap is still not safe to use. Place your bars in a well-ventilated area, away from direct sunlight and allow them to cure for a minimum of 1 week until it is safe to use, and 3-6 months for best results. I let my soap cure on an open shelf that doesn’t get direct sun. The longer the cure, the better (but not more than 10 months). Remember to turn them occasionally (every week is good), so that each side gets exposure to the air.
  17. Lather up! You can use this soap in the bath or for the dishes. You can even grate it up and use it for laundry. It’s that versatile.


1.) If you want to customise quantities: You can use this helpful online calculator to work out the exact quantities of oil, water and caustic soda if you’d like to use different quantities and different oils than this recipe, or if you’d like to experiment. This tool also allows you to see what quality of soap you’ll be making based on the oil combinations you choose. You can see the hardness, soapiness and cleaning factor of the soap before you even begin making anything. This recipe uses a 2:1 water:lye ratio, and a 0% super fat. You need at least a 1:1 ratio, but it’s better to have more water to make sure there is enough for all the caustic soda to dissolve, and to prevent a very fast trace. If you use less water than this recipe, your batch may accelerate to trace and start bubbling up or volcano, which will lead to a very crumbly bar of soap that will be difficult to cut.

2.) Coconut oil is less dense than water, so when you buy a 1 litre coconut oil tub, you will probably only get about 920 grams of coconut oil, hence this recipe asks for 900g of coconut oil which is approximately what you will get when you buy a 1 litre bucket. But you must still use a scale to double check the weight!

Cost & Shelf Life

Cost price: R6.97 per 100g soap bar.
Lasted me about: 1 month using every day for dishes (one bar).
Shelf life: 2 years if stored away from direct sunlight.

*Costs accurate at the time of writing, and based on the best retail prices I’ve found.


Long curing time: One week is not necessarily a long time, but when you’ve just made your first batch of soap, you will obviously be eager to try it out, so one week may seem like forever. This recipe uses the room temperature/ cold process method (CP), but if you’d like to cut the curing time substantially, then you may want to consider the hot process method (HP). This method requires you to be much more precise with temperatures, you need a crock pot/ slow cooker and the method is much longer (2 hours to the mould step), but the curing stage is much shorter. Whereas, the cold process method is quick (30 minutes to the mould step), but the curing stage is longer.


  • Customisable: You can completely customize this soap recipe. You add essential oils/ scents, colouring and textures according to your preferences.
  • Cost-effective: You can make organic soap in bulk, and save the cost of purchasing it all the time.
  • Many uses: This soap bar can be used as dish washing soap, laundry soap and as part of a laundry powder recipe. You can also melt it down to make a basic liquid soap.  Alternatively, you can learn how to make liquid soap from scratch.
  • Eco-friendly: this recipe contains only what you need, and is biodegradeable.

I‘d love to know what you use this multi-purpose soap bar for and how it works for you? Please share in the comments below.

2 thoughts on “Multipurpose Soap Bar”

    • Lemon juice is known to make soap seize, and if you add too much, the acidic nature of lemon juice will cause the soap reaction to occur backwards, because lemon juice will neutralise the lye and make it ineffective. In other words, your soap will turn back into oil. Even if it did technically work, you would still lose the beneficial properties and the natural fragrance of the lemons. Rather add dried lemon zest or lemon essential oil, but again, not too much. I recommend adding about 5ml lemon oil to every 1kg soap. Also, lemon essential oil’s fragrance has a reputation for fading. If you like the fresh fragrance, it would perhaps be better to use a fragrance oil (which is not natural), or an essential oil that has a similar fragrance profile like lemongrass or lemon verbena.


Leave a Comment