Mis à jour : 25 mars 2020
Difficulty Level 4
This is a basic recipe for how to make glycerin soap that is clear. It takes a bit of practice to get it clear. My first batch turned out cloudy and I think it was because the soap base I made wasn't dissolved enough. Take your time and be patient!
Why make it?
The first thing to say is that you could, of course, avoid all the hassle and buy a transparent Melt & Pour soap base but be aware that many contain some nasty ingredients that help the soap foam. Glycerin, as you know, is a natural by-product of saponification. It is a humectant meaning that it draws moisture from the air. When using a natural soap, this moisture penetrates the epidermis which then seeps outwards to form a protective and highly moisturising fine layer that keeps your skin hydrated for a long time.
The second thing to say is that there is nothing more rewarding than making your own. Many soapers like to use glycerin soap as embeds in cold-process soap as you can create some gorgeous, unusal soap designs such as "stained glass window" effects along with soap gems and much more.
By learning this technique you'll always have this useful soap base in your soap-making tool kit.
Important Info before you begin
In order to achieve a good end result, we need a recipe that renders a pliable transparent dough like substance with no sodium hydroxide or fatty acids remain free in the finished product. This recipe therefore has a zero margin of security (lye discount) which means that you must be super accurate in your weighing skills ! However, the crock-pot method will speed up the saponification process and eradicate any remaining sodium hydroxide and fatty acids.
You MUST check the pH of your finished soap product before using
It uses 18% of water to fatty acids instead of the usual 38% meaning that trace will appear very quickly despite the recipe being high in unsaturated fatty acids. A speedy trace is ideal for this recipe.
It uses a crock-pot to accelerate saponification and requires additional ingredients to be added at point of trace which includes a) 70% alcohol and liquid glycerin and b) sugar syrup (sugar and water) to boost the lather.
This is considered a level 3 (advanced) technique for more soap makers who are 100% accustomed to and confident with saponification, from the handling of raw materials to understanding the chemical reaction of saponification.
If you are nervous about making a soap base with a tiny security margin, I suggest that, for now, you buy your clear Melt and Pour base.
Please do not attempt this recipe is you have any doubts ! You could book a private masterclass session at the Centre de Formation SAF me where I can teach you this technique for example, along with using your M&P base reatively within CP soap.
RECIPE & TECHNICAL KNOW-HOW
CLEAR GLYCERIN SOAP
Soap weight before cure: 936g
SKILL LEVEL: 3 Advanced
RAW MATERIALS SOAP BASE
198g Sweet Almond Oil
77g Coconut Oil
113g Castor Oil
10g Sunflower Oil
56g Sodium Hydroxide (solid - crystals, flakes, pellets)
72g distilled or filtered water
184g 70% alcohol
NOT Isopropyl aka Rubbing alcohol/ Surgical Spirit
43g liquid glycerin
70g distilled or filtered water
Crock-pot or slow cooker
Never ever reuse any utensils stolen from the kitchen to make soap for food preparation ever again !
Prepare the sodium hydroxide solution (lye) and allow to cool to 65°C or 150°F
Weight all fatty acids into a slow cooker/crock-pot and heat to 57°C or 135°F.
Add the lye water to the oils in a slow steady stream.
Bring the mixture to a trace (resembles thick custard) with an electric hand blender
Keep the heat at medium/low for a few hours, checking on it regularly.When it reaches the gel phase, it will look translucent like petroleum jelly. Stir once in a while, but not all the time. If it gets too thick, use a stainless steel potato masher and work it through to break the paste down
After a few hours, take a bit of the soap and try to dissolve it in a cup of hot water. If it dissolves, you can move on. If it stays in a lump or has oil floating on the top, you need to "cook" it more. Leave it for half an hour and try again. If it's ready, then add: 184g alcohol - 70% or higher 43g liquid glycerin
Be very careful as alcohol has a low flash point and can alight very easily. This is why the crock pot method is far softer than the stove-top method for heating. You may need to mash the soap up some. Do a bit at first, then do more in a little while. If you mash too much at once, you may get a lot of suds. This process can take a few hours, so be patient.
When the soap is all dissolved, there will probably be a few particles floating on top. These are impurities and must be removed. Skim them off and throw them away, or you can place them in a jar, cover with hot water, and use for dish soap.
When the soap is fully dissolved combine 113g sugar and 70g water and boil until the sugar is completely dissolved. Do not leave any crystals undissolved. When it is totally liquid, pour into the soap base. Stir and cover, then cool to 62°C or 145°F.
Now you can pour it into a mould of your choice. I like to use silicone ice-cube trays as the size of the cubes are ideal when using creatively. Cover with plastic wrap and let sit for a week or more. When it is clear (it may take longer than a couple of weeks), de-mould it and cut it into pieces and store in an air-tight glass jar.
If you see small blobs forming of the surface of your soap, do not worry. This is the glycerin doing its good work by drawing in moisture from the air into the soap. In glycerin soap, this is called “sweating” . You might want to wrap up your soap in plastic film to prevent it sweating and then store it in an air-tight jar.
Important Notes on Making Glycerin Soap
70% alcohol may be hard to find. Don’t use isopropyl alcohol, you will never get rid of the smell! I use Aromazone Base neutre, a 100% natural alcohol product, normally used to create scented sprays and perfumes. If not, ask at your local wine and beer-making store. They can recommend what may work. Keep the alcohol clear and unscented.
When subject to heat, alcohol can ignite, so be cautious!
The recipe includes Sweet Almond oil which has a SAP value of 0.139. This can be replaced with another fatty acid with the same SAP value. Replacement oils with the same SAP value fall into the tallows..i.e. animal fats such as goat, deer, beef, duck etc. Other vegetable oils do have the same SAP value but these are a) expensive to use in large quantities, b) are strong smelling and have a strong base colour that will result in a slightly coloured transparent soap. Do your own research or create your own recipe remembering that your security margin and super-fatting values are 0% and that the water quantity is reduced from 38% to 18% of base oil weight
These instructions are for clear soap. Add some titanium dioxide or zinc oxide powder to get a white soap that will produce pastels when coloured.
White sugar produces the best results. Raw sugar can be used but your soap will be more amber coloured.
Using Your Glycerin Soap Base
Once you make glycerin soap you’ll see how fun it is to work with. All of the lye and oils have been worked out, leaving you with a very pliable base that can be melted in the microwave, and made into some very colourful transparent shapes, ideal for embeds and much more.
This Geode soap was made out of 100% Melt and Pour soap. For details on how to make this from your own Melt and Pour Base, see the feature GEODE
This is a very safe way for children to experience soap-making. They will love melting it, colouring and adding their fragrances and turning into fun shapes. The learning process will also help them understand the benefits of using a natural soap.
Prepare your moulds. Set them on a flat surface and get your fragrances and colours ready.
Calculate how much soap base you need to fill your mould(s). If you can’t remember how, revisit your soap-making manual you received on the Introduction to Soap-Making course, level 1. you’ll need . Weigh out a little more as some of the glycerin soap will remain on the container and spoon.
Place as much soap base as you need into a heatproof container to melt it. Place the container either in a bain-marie (a pan of hot water) or into the microwave on 30-50% power. Stir occasionally until fully melted.
Add a few drops of colourant (food colourings are ideal) if desired. Stir well. Add more if needed.
Add the essential or fragrance oil (maximum 3% of total soap weight), a few drops at a time and stir well.
Add in any other additives you like such as dried herbs, salts, seeds etc and pour into the moulds.
If the base cools too much and gets chunky or stiff, just remelt it and stir. Let the moulds sit until the soap is completely cooled. Larger moulds will take longer.
When cool, gently pull the mould away from the soap and push on the back side of the mould to release. Wrap soap in plastic wrap or wax paper. You must wrap it right away or it may collect moisture from the air and bead “sweat” on the surface. While this is a sign of good soap, most people don’t like the look of it and it is hard to use
Cleaning up is easy. (After all, it’s soap you’re cleaning off your supplies.) Just soak the moulds in hot water, rinse and dry well.