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How to… Make Soap

March 21, 2016

As soap forms the basis of so many of the recipes for the homemade cleaning products that I want to share with you guys, I thought I should go over a basic soap recipe, in case anyone is keen to have a go! The more I read and learn about making soap, the more I realise how much there is to read and learn. I am only at the very tip of the iceberg, and although it’s actually a pleasingly simple process, there is quite a lot to take on board, so be warned, this is a bit of an epic post!

Before we get into the ‘how’ I thought it might be good to spend a minute exploring the ‘why’. Why go to the bother of making your own soap?

  • It’s packaging free
    I started using soap a year or two ago, when I was trying to cut down on the amount of single use plastic I was using, and my focus turned to the bathroom. I decided to replace shower gel with good old fashioned soap, and spent a while trying to find sustainable versions. Everytime I bought soap, I kept thinking that I really should have a go at making it, but whenever I started to research it, I got put off by the dire warnings about lye, and the equipment needed. Eventually I decided that I should go on a course, to get an expert to show me, and I’m really glad I did-I think I learn better ‘in real life’ than I do from books, or even from online videos etc. Having said that, I am now going to try and show you all how to make soap online..!
  • It’s all natural and moisturising
    Soap making is an ancient ‘art’ and is a magical process that converts oils and lye (caustic soda) into lovely smooth soap.
    Homemade cold processed soap is a world away from commercial soap. When soap is made commercially, the glycerin is extracted and sold off, as it’s a fairly valuable commodity. By leaving the glycerin in, homemade soap is moisturising and gentle, and doesn’t dry the skin out.
  • It can be used to make a whole host of other products
    Since learning to make my own soap I’ve also made homemade washing powder, dishwasher tablets, a liquid hand soap, and an all purpose cleaning spray
  • It’s cheaper than buying good quality soap
    Trying to find sustainably produced soap, packaging free is actually pretty easy-there are some fabulous soap makers out there. But if you are using it a lot, and using it to make other products, it can get quite expensive.
  • You can customise it-the ingredients, and the essential oils, to completely suit yourself and what you want.
  • Just because you can!
    It’s actually really fun to spend a morning making soap, and I always find making my own things rather than buying them an empowering and satisfying thing to do!

Rapeseed:Coconut soap

OK, so now you are convinced at the merits of homemade soap, here’s some practicalities:

  • The lye that is used to turn the oils into soap is pretty nasty stuff-it’s caustic and it burns if it comes into contact with your skin. I’ve put together a soap making safety page here-please read it!
  • Each different type of oil needs a different amount of lye to turn it into soap, so if you make any changes to recipes, make sure you run the recipe through a ‘Lye Calculator’ like this one here.
  • The oils and resultant soap can apparently react with some metals and other salts, so the advice is to use stainless steel or enamel saucepans (not aluminium); plastic or pyrex bowls and jugs; and silicone whisks. For the same reason, filtered or distilled water is recommended, to avoid all the minerals in hard water. We use charcoal to filter our water, and I was really worried that this wouldn’t filter it enough. But I kept forgetting to buy a filter cartridge, so have been using it, and so far it seems to be ok.
  • The list of equipment needed is one of the things that put me off. Ideally you should use separate equipment to anything you use to cook with. I made life harder for myself by trying to source everything secondhand, but I also proved that it is possible! After a little bit of perseverence, I managed to course two saucepans from charity shops; I was gifted a hand blender on our local Buy Nothing site; I found a silicon whisk and a plastic bowl in a charity shop; I randomly had two jam thermometers, so commandeered one for soap making; and I had a spare plastic jug.
  • The Soap Kitchen is a great place to buy equipment and supplies, if you are in search of a one stop shop. If you are looking for secondhand, then check out eBay, Gumtree, and sites like Freecycle/Freegle.


Soap making equipment-small

  • Large stainless steel saucepan-all the books and blogs say that the saucepan it has to be stainless steel, rather than aluminium-it’s something to do with the fats reacting with the aluminium. You wouldn’t believe how hard it was to find a stainless steel saucepan secondhand-I took to carrying a magnet around with me to test any I found in charity shops!
  • Jam thermometer x1 and soap thermometer x1, or 2 soap thermometers. The soap thermometer is to use with the lye, and if you use a jam one, the numbers will float off…!
  • Silicon whisk, or hand blender
  • Plastic or pyrex jug
  • Plastic or pyrex bowl
  • Mould-you can buy special moulds, but if you are just starting out and seeing if you like it, you can use a tupperware box, or even a tetrapak
  • Greaseproof paper to line your mould
  • Silicon scrapers
  • Safety gear: apron, rubber gloves, safety specs
  • Digital scales-I just use my regular kitchen ones
  • Towels and a cardboard box to insulate your soap (I used my wonderbag!)
  • Vinegar in a spray bottle. If you get splashed with lye accidentally, spray the area with vinegar to neutralise the caustic soda.


This makes a batch of about 1200g of soap, which makes 10 decent sized bars. You can make a smaller batch by halving all of the ingredients, but I always figure that it takes me as long to make 600g of soap as it does to make 1200g so I might as well make a bigger batch!

  • 600g olive oil-I used this organic one here from the The Soap Kitchen. It doesn’t have to be extra virgin for soap making, in fact, the cheaper ‘pomace’ oil works better
  • 300g coconut oil-I used this organic one from The Soap Kitchen. The only fairtrade coconut oil I could find is this one from Lucy Bee
  • 300g rapeseed oil-I used Fussell’s Rapeseed oil as it’s made just up the road from me. Have a look around locally, as rapeseed oil production seems to be getting more popular, and there might be a producer local to you
  • 167g Sodium hydroxide (lye)
  • 350ml filtered water
  • 30-40g essential oils of your choice-I used lemon and bergamot


Sopa Making-P

  • Read the safety guidelines!
  • Line your mould with greaseproof paper-if you are using a tupperware box this isn’t strictly necessary but it will make it easier to get the soap out
  • Place your large saucepan on the scales, and carefully weigh out each of your oils into the pan
  • Heat the oils gently on the hob. Pop the jam thermometer into the pan, and allow the oils to heat up slowly to about 60C
  • While the oils are heating, prepare your lye:
    Measure out the filtered water into a large plastic or pyrex bowl.
    Place your plastic jug on the scales, and CAREFULLY pour out your lye crystals-once the lye is in the jug it can have a tendency to clump, so I was told to carefully swirl the jug to keep the lye from clumping.
    Take your water and your lye outside, and carefully add your lye to your water (always this way around. NEVER add the water to the lye-it could all fizz over/explode). Stir gently, keeping your head out of the way of the fumes.
    Place your soap thermometer in the bowl-the water/lye mix will get really hot and the thermometer will shoot up to around 90C
    Leave the lye to cool
  • Keep a check on the temperature of both the oils and the lye-the aim is for them to both be at the same temperature-about 50C
  • When they are both at about 50C, carefully pour the lye into the oils, and start to stir with the whisk. It is possible to bring the soap to ‘trace’ using a whisk and stirring by hand, but it can take a while. I am impatient, so I use a hand blender. BUT it can create extra splashing, and it is also possible to over mix it and the soap will clump. I blend in short bursts of 5-10 seconds, and then stir well with the whisk or a silicon scraper, and then blend again for another 5-10 seconds etc.
  • Keep whisking/blending. The mix will become opaque and will start to thicken. The soap needs to be bought to ‘trace’ which is kind of a thick double cream consistency. When you allow drips to drip back into the pan, you should see a ‘trace’ of their drips for a few seconds afterwards. (I will try and get a picture next time I am making soap!)
  • Once the soap has reached trace, add your essential oils, and mix in well with the whisk/silicon stirrer
  • Carefully pour your liquid soap mix into the moulds (it is still caustic at this stage)
  • Lay a piece of greaseproof carefully over the top (this stops air getting to the soap and causing something called soda ash)
  • Place a towel in the bottom of the cardboard box, and carefully place your filled moulds on top. Place another towel on top of the moulds, and around the side, so that the moulds are all snuggled up and cosy
  • Leave somewhere warm for 24hrs
  • Unwrap the soap, and remove from the moulds-it can still be a little caustic at this stage, so be careful
  • Put the soap somewhere to ‘cure’-I have a shoe rack set up in the kitchen. I leave the soap in bars for another 24hrs, before cutting and then leaving to cure for 4-6 weeks. It makes the kitchen smell amazing!
Coconut oil soap-small

100% coconut oil laundry soap-I’ll share this recipe soon!


  • I lay out a couple of silicone baking tray liners on my worktop before I get going, as I have been warned that the lye solution can permanantly mark worktops and tables. I’m just passing that warning on!
  • When you insulate the soap well, it goes through a process called ‘gelling’ where it becomes more translucent. When the soap has gelled, my understanding is that all the lye has saponified, and the soap should no longer be caustic. If your soap gels all the way through, it is therefore safe to use straight away, BUT it’s advisabel to leave it to dry and harden up for a few weeks, to make each bar last for longer.
    I’ve had some trouble with my soap only partially gelling, and I think it might be because the soap is losing heat too quickly. If this happens, don’t panic-it will still be perfectly usable after it has ‘cured’ for 4-6weeks, and it will be a purely cosmetic issue. But it won’t be safe to use straight away, like the fully gelled soap.
  • To decide on essential oil mixes and ratios, use a pipette to place a drop into a jam jar. For example, if you want to try lemon and ginger, drop in 2 drops of lemon, and 1 of ginger to see if that ratio works.

Lemongrass and Ginger 2

Additional resources:

The Soap Queen – a great site with LOADS of recipes and instructions, as well as some trouble shooting guides
The Soap Kitchen – UK site for supplies and equipment, but also has some recipes and instructions
Pinterest – I’ve created a soap making board on Pinterest, with links to loads of different soap making posts
Natural Soap Forum – I joined this Facebook group, and it is a really friendly place with lots of knowledgable people and some useful recipes and information in the Files. It seems to be mostly Americans on there, but I think there is a UK contingent!

I hope that all makes sense-please let me know if it doesn’t.
And please do share your soap pictures with us if you do have a go!



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  • Reply clare @ maybush studio August 4, 2016 at 8:02 pm

    I’ve been looking at the bottles in my shower over the last few weeks feeling like I have to do something about them so this is very interesting… I’m not sure I’m ready to make it yet, but…. one day!

    • Reply Jen August 4, 2016 at 8:13 pm

      There are lots of other options if you don’t fancy making your own soap Clare ???? Lush do soap by the 100g and package in paper bags so could be a good place to start. They also do shampoo bars too which are packaging free and work really well.

    • Reply Anji King April 13, 2017 at 8:46 am

      I also don’t feel quite ready to tackle making my own! A couple of my local health food/ethical type shops sell some natural soaps without plastic packaging. And one of them does refills for Faith in Nature shampoo & conditioner and some natural household products e.g. washing up liquid, so I now take in my old bottles and refill in the shop.

      • Reply Jen May 5, 2017 at 9:42 am

        Brilliant! These are all great steps Anji 🙂

  • Reply Jeanette Bruffett March 22, 2016 at 2:53 pm

    thank you for this tutorial! I have made soap once with a friend but now find that I need to get out on my own and give it a go. Your post is encouraging.

    • Reply Jen March 23, 2016 at 6:26 pm

      Thanks Jeanette-so pleased it’s useful! Do let us know how you get on 🙂

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