Making cold process soap is as simple and pleasing as cooking, and with techniques that have barely changed over the last few hundred years, it is a traditional skill that is easy to master. Cold process handmade soap is gentler and less drying than commercial soap as it retains glycerine as a natural by-product.
In the past, families would have a soap day on which they would make enough soap to last the whole year. Now with the advent of sodium hydroxide you are no longer saving wood ash to make an alkali, nor do you need to wait for the fat. By simply assembling ingredients according to the recipe and a few basic items of equipment, luxurious soap can be made in just a few spare hours. The cold process technique is used in many of the projects in this book. Be sure to read the safety advice before you begin and, most importantly, enjoy it!
• 300g (101⁄2oz) coconut oil
• 600g (1lb 5oz) olive pomace oil
• 300g (101⁄2oz) palm oil
• Botanicals and essential oils (NB: Add required amounts as per the recipe you are following)
• 375ml (13fl oz) cold filtered water
• 168g (53⁄4oz) sodium hydroxide (caustic soda)
1 Grease your chosen mould with a small amount of melted coconut oil and a paintbrush
2 Line your mould using greaseproof (wax) paper, folding it over the edges of the mould. (This is not necessary if you are using a silicone mould.)
3 Weigh out the olive pomace, coconut and palm oils into your pan and heat them while stirring until all the solid oils have melted and the temperature is approximately 60°C (140°F). Take the oils off the heat and leave to one side, placing a thermometer in the pan.
4 Weigh out all botanicals and essential oils according to the recipe you are following. Remember to use rubber gloves to handle essential oils.
5 Measure the water into a large bowl and weigh out the sodium hydroxide into a dry clean jug. Wear your goggles and rubber gloves and work in a well-ventilated area.
6 Add the sodium hydroxide to the water while stirring. Be careful to turn your head and do not inhale any of the fumes released. Once it is stirred thoroughly and all the sodium hydroxide has dissolved, leave the mixture to one side and place a thermometer in it.
7 Over the next hour, periodically check the temperature of the oils and the sodium hydroxide mix. Once the two mixtures are approximately 52°C (125°F) slowly and carefully pour the sodium hydroxide mix into the oils.
8 Whisk the mixture constantly until it starts to thicken and leaves lines in the wake of the whisk. This stage in the process is known as ‘tracing’ and can take anything up to an hour or more. Test if the mixture is tracing by lifting the spoon out of the mixture and dripping the liquid along its surface. If it sinks without a mark it is not tracing; if it leaves lines in the surface it is ready.
9 Once trace occurs add the essential oils and any botanical ingredients if you are using them, and stir thoroughly.
10 Carefully pour the thickened mixture into your prepared moulds.
11 Place cling film (plastic wrap) directly onto the surface of the soap in the mould, covering it completely to prevent the formation of soda ash. Lay out towels or blankets followed by cardboard onto your work surface, place the moulds onto the cardboard and add extra cardboard over the top. Finally wrap the blanket or towels around it to prevent the soap from cooling too quickly. Leave to cool for about 24 hours.
12 Once the soap is cold, pull it out of the mould using the folded lining paper to release it.
13 PH test your soap by dissolving a shaving into a small amount of water and dipping a pH strip into the mixture. The pH should be 10 or lower and in most cases it will be pH 8 or 9. If the soap is above pH 10, leave it for a few weeks to cure then test it again.
14 Once dry, cut the soap into bars and leave them to harden for four to six weeks (see Cutting and Curing Cold Process Soap), ensuring there is space between each bar for air to circulate. Turn the bars weekly. The longer the bars are left to dry, the harder and longer-lasting the soap will be.
When working with sodium hydroxide, keep vinegar spray to hand at all times. Vinegar will neutralize the alkali if the sodium hydroxide comes into contact with your skin.
If the soap is not released from the moulds easily, place them into the freezer for approximately eight hours. Once frozen, remove the moulds and while wearing gloves, turn the soap out onto a tray or similar surface to thaw.
If the oil temperature has dropped too low you can gently reheat it, remembering to remove it from the heat when it is several degrees lower than you require. To cool overheated oil, place the pan in a sink of cold water and stir until it reaches the desired temperature, removing it when it is a few degrees higher than you need, as it will continue to cool.
Melt and pour soap base is a form of pre-made soap that allows you to make your own in a short time, without the chemical processes involved in the cold process technique. It is a product that is simple and safe for both children and adults to use. There are certain chemicals added to the soap to allow it to be so flexible and easy to use, but it is very good for making small, pretty soaps and does not have the long cure time that cold process has. Melt and pour comes in clear and opaque varieties, both of which take colour and scent well and can have botanicals added.
• Stephenson clear or white melt and pour soap base (see Suppliers)
• Rubbing alcohol
1 Weigh out the amount of melt and pour soap base required for the recipe. Cut up into small chunks to allow for quicker melting.
2 Place the chunks in a microwaveable bowl or small pan and melt slowly on a low heat to avoid bubbles and overheating. (Ideally heat to around 120°C (250°F) or check the optimum temperature with the manufacturer.)
3 Once the soap has melted you must work quickly to add your fragrance, colour and botanicals as a skin forms quickly. You can re-melt it if a skin forms, but this may allow the fragrance to evaporate, so avoid if possible. Use colour sparingly – too much will affect the transparency of the soap and in some cases produce coloured lather that can stain baths and linens. Do not add too much in the way of glitters and iridescent powders as they can sink to the bottom in excess.
4 Once you have added all your botanicals, pour into the moulds.
5 Spray the surface of the soap with rubbing alcohol (available from chemists/drug stores) to remove any bubbles.
6 Once hard, you can unmould and use. If your soap does not come out easily, place it into the fridge for a few hours to harden and pull away from the sides of the mould. Do not freeze as this can cause the finished soap to crack.
Because melt and pour does not require the high temperatures of cold process, the botanicals retain their colour and structure. There are no special materials required; simply heat small quantities in the microwave or large quantities in a pan.