How To Make Your Own Soap




When planning my lessons for my year 7 and 8 Design and Technology class I had the idea to try making our own soap from scratch. After searching for methods for a while on the internet I thought it best to try to find someone locally who has been successful at soap making and see how they did it. Luckily for me, I came across a lady who makes soap for a living and she was generous enough to allow our class to make a field trip to her home/shop where she demonstrated much of the procedure. (You can read more about that here.)

After a few practice trials myself and several runs with my students that produced successful batches of soap, here is my recommendation for how to make your own soap. This allows for you to save money as well as use better ingredients of your own choosing to insure no use of animal products.


Making soap is not so hard so long as both procedure and recipie are followed rigidly. I would recommend wearing safety goggles, an apron, long sleeve shirt and gloves just to be safe though as you will be working with caustic ingredients that could cause injury if splashed (especially in the eyes).

At the onset it is worth mentioning that (except for the water content) the ingredients are measured by weight and not volume. If you don’t have a small kitchen scale then you should stop here as guessing could render you with something that deceptively looks like soap but could have a caustic highly-alakaline PH that could burn sensitive parts of your skin. Get an accurate kitchen scale (digital is preferred) and then continue on.

Equipment Needed:

– kitchen scale (accurate to 5g – digital is preferred)
– two cooking thermometers (we purchased ours at the local supermarket for less than $10 each)
– one cooking pot
– three medium sized stainless steel mixing bowls
– one small bowl
– one kitchen submersable stick blender (looks like this)
– one clean 1 liter milk carton (open up both flaps at the top and give it a good rinse)
– apron, rubber kitchen gloves, goggles and a mask if you have sensitive lungs
– one metal stirring spoon
– one stirring spoon of any kind
– a small funnel
– thick towel
– kitchen knife

Ingedients needed:

– 750g olive oil (note that the unit is Grams and not mililiters)
– 250g coconut oil (available at your local indian grocer)
– 135g caustic soda (Sodium Hydroxide (NaOH)) (can be found in the cleaning product section of your supermarket near the drain cleaner stuff. the brand used in this recipie is ‘Diggers’ available in a 500g short plastic package with a red safety lid.)
– 300ml of water (note the unit here is not weight but volume)
– 10g loose lavender flower bits (pick the fluffy bits off the stems and throw out the refuse as it is too scratchy to be included in the soap)
– a few drops of lavender essential oil (optional but nice)

It is important to have everything planned and measured out beforehand as the whole process is time critical with little margin for error. If this is your first attempt then run through the procedure a few times in your head after you’ve measured out all of your ingredients.

1.) put the cooking pot on the scale and pour 750g of olive oil into the pot. Note the weight and then pour 250g more of coconut oil into the same pot. when you are done put this pot aside.

2.) now put one of the medium sized cooking bowls onto the scale and carefully pour 135g of caustic soda into the bowl. Don’t include the weight of the bowl in your measurement so that you actually have 135g of soda. !!!!!!!!! Make sure the bowl is completely clean and dry first as the soda can be volatile when in contact with small amounts of water. !!!!!!!!!!!!!!!

3.) now measure out 300ml of water into the last medium sized bowl

4.) put the cooking pot with the oils on low heat on the stove and allow it to heat up to around 60 degrees celcius. for this you can dedicate one of the thermometers.

5.) while the oils are heating you should move the bowl with the water into it near an open window to allow for ventilation. if your kitchen has an exhaust fan you should turn it on too.

6.) now carefully pour the measured caustic soda into the bowl of water and immediately stir with a metal utensil. try not to breathe in the fumes as they are caustic for your lungs. if you are really sensitive then wear a mask. be careful not to splash over the side as it can cause burns and will also throw off the proportions in your soap recipie. !!!!!!!!!! IT IS VERY IMPORTANT NOT TO ADD THE WATER TO THE CAUSTIC SODA AS IT IS EXTREMEMLY VOLITILE. ALWAYS ADD THE CAUSTIC SODA TO THE WATER AND NOT VICE-VERSA !!!!!!!!!!!!!

7.) keep stirring the caustic solution and check the temperature with the other thermometer. you will notice that it will heat up to around 80 degrees celcius due to a chemical reaction.

8.) here is the tricky part. after the caustic soda heats up it will start to cool down. The pot of oil should reach 60 degrees and then cool down. The optimal temperature for both solutions should be 50 degrees. Try to time it so that the pots cool down to 50 degrees at the same time. the caustic soda solution should be allowed to reach this temperature on its own and/or with your stirring. The oil can be reheated or even poured into the remaining medium mixing bowl to expedite its cooling.

9.) When both the oil and caustic soda solution reach about 50 degrees then pour the oil into its own mixing bowl if you haven’t done so already. DON’T POUR THE OIL INTO THE CAUSTIC SOLUTION AS IT WILL CAUSE SPLASHING. Now pour the caustic solution into the bowl of oil and notice how instantly the oil reacts to the solution. Place the bowl that had the caustic solution in it, the thermometer and metal stirring spoon into a sink and quickly rinse with water.

10.) Add a few drops of essential oil to the mixture.

11.) Now use your stick blender to mix the combined pot of oil and caustic solution. You should keep the blade submerged to avoid mixing air bubbles into the soap mixture. Within a minute or so the solution should start to thicken to the viscocity of thin custard. As soon as you can trace a noticable line with your blender you are ready to pour the solution into your milk carton. This means that the mixture is just slightly thicker than liquid. If you’ve made it like thick custard then its too much and you’ll have a harder time pouring it.

12.) add the fluffy lavender bits and gently mix in with a stirring spoon.

12.) put the funnel into the fully open end of the milk carton. hold it there with one hand. with your other hand carefully pour the mixture into your carton.

13.) spatula out the rest of the mixture into the carton and then close the carton. write the date on the carton along with the type of soap ‘lavender’. (this could be done beforehand)

14.) wrap the carton in a thick towel to retain warmth and leave it in a warm place for a couple of days.

15.) whenever the mixture has set to the point where the sides of the carton won’t budge when pressed. (no liquid content left inside) then soap is ready to be cut and cured.

16.) Put on your gloves. Using a knife and starting from the bottom of the carton, cut the soap in about 1.5cm blocks. you can cut though the carton and then peel the carton off each piece.

17.) If you have a little soap left over at the end near the opening then you can (with a gloved hand) roll this into a little soap ball.

18.) Now this soap needs to be placed on some sort of rack where the air can get to all sides of it. I use an seedling cabinet in the back room of our house. It shouldn’t be put into direct sun or into a damp place. it needs to be able to air out but not be exposed to the elements.

19.) Let the soap sit for one month (YES. One month!) so that the caustic solution reacts fully with the oil (called the saponification process) and the PH comes down to near neutral. You can buy litmus paper at the local pool shop if you want to test it but a month is sufficient time for you to be confident that your soap is ready to use. By now the bar should be fairly hardened.

This recipie is tried and true. If you want to experiment then I’d suggest you alter first the different herbs and essential oils to come up with different recipies. When you’re fairly confident then you can try different combinations of oils. Be sure to use this calculator first though as different combinations of oils have different saponification values and require a varying amount of caustic soda solution accordingly. (link to online soap making calculator)

As a general guide – olive oil produces a very soft and minimally lathery soap by itself. coconut oil provides lather and hardness to the bar as well as a whiter consistancy. There are lots of other oils and combinations of oils that can be used but each will need to be calculated to determine the amount of caustic soda and water needed for saponification.

That’s it. I hope I haven’t left anything out. If you have any questions then don’t bother leaving a comment on this blog. Just write to me on email: ekendra AT


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