by Helen Prout
Salt soaps are undoubtedly one of the soaping industries best kept secrets. They produce a heavy, long lasting bar, with a creamy lather that leaves your skin feeling soft, clean and moisturised.
Due to salt’s natural anti-microbial properties, people have been using it to preserve food for millennia. This property translates to make salt soaps an excellent deodoriser; useful both in the kitchen, and the shower (it also explains why so many people use salt crystals as natural deodorants).
As salt soaps set up remarkably fast, they are best suited to small batch rather than large scale production, so you typically won’t find them in your local supermarket. As anyone who has tried to wash in sea water can attest, salt reduces the lather of soaps and shampoos. To counteract this, soap makers use a minimum of 80% coconut oil in their salt soaps, as when coconut oil goes through the saponification process, it becomes a super cleaning, bubble making machine. Whilst coconut oil in its raw state is known for its moisturising properties, when used in soaps in large amounts (over 30%), it can be drying on the skin – for this reason, a higher superfat is typically used in salt soaps – anywhere from 10-20%.
When choosing a salt to use, select from Sea Salt, Pink Himalayan and Table Salts. Both Epsom and Dead Sea Salts are unsuitable, as they have high mineral contents which affect soaps’ ability to set. When selecting the grade of salt to use, opt for fine rather than coarse, as this will result in a smoother bar suitable for all skin types.
Having tried many Salt Soap recipes, I’ve come to prefer recipes with a salt to oil ratio of 65%: 100% as this produces a bar that doesn’t crumble, looks well and leaves my skin feeling pampered.
When making any soap, but especially salt soaps, it is extremely important to have a back-up plan in case the soap sets up quicker than expected e.g. a set of less intricate moulds; a strong spoon to put soap into moulds with (if it is too thick to be poured); another pair of hands to help.
- Assemble your ingredients, soap moulds and put on your safety clothing.
- Weigh out your water, and pour it into a tall sturdy plastic jug.
- Weigh your lye into a container.
- Break up any lumps in your salt.
- Whilst in a well ventilated location pour the lye into your water. Stir with a spatula or plastic chopstick until fully dissolved. Leave the lye to cool for approximately 1 hour, until it reaches 90°F or 32°C (measure using jam thermometer).
Note: When making salt soaps, I work at lower temperatures (i.e. for my oils and lye), to slow down trace.
- If using a colourant, add it to the lye water now.
- Weigh the oils and add them to your saucepan. Heat the oils until they reach 32°C, and then turn off the heat.
- When the lye and oils are approximately both at 32°C, slowly add the lye to the saucepan of oil. Intersperse manually stirring the stick blender, with turning the blender on for short 5 seconds bursts. Continue to do this until the soap reaches very light trace (estimate this taking 1-5 minutes). A ‘trace’ is when the stick blender leaves a mark on the surface of the soap, upon lifting/dragging it across the soap’s surface.
- Add the salt (and essential oils if using) to the soap batter now. Pour the batter into a sturdy plastic jug.
- Pour the soap into a heavy duty, flexible, silicone loaf or individual moulds. Stop to frequently stir the soap batter, as the salt tends to sink to the bottom. Cover the soaps with clingfilm, if required, before placing out of sight, in a dry location.
- If you are using individual moulds, you should be able to un-mould after 2 days. If you have poured the soap batter into a loaf shape, then you will need to un-mould as soon as it starts to firm up, but before it becomes too hard and brittle. This will typically mean that you will have to un-mould within a few hours (or less), and cut it whilst it is still warm (making sure to wear suitable gloves).
- Place the soaps in a lined box, in a dry place, like a linen cupboard. Turn the soaps every so often, so that they dry evenly.
- Many soap makers leave containers used for making soap, until the next day to wash – as most of the lye will have been neutralised by this stage. Use good gloves and hot water.