Soap

Back when I was about 8 or 9 years old we were learning about farming at school and somewhere in those lessons I remember my teacher telling us that soap could be made by mixing lye made from the ashes of a fire with fat. For some reason that information stayed with me and I often thought that I really should give it a go because it sounded both simple yet mysterious. But, as with so many other things in life, soap-making turned into one of those things that I always meant to have a go at yet never quite got around to doing.

Then in the summer of 2022, my friend Gabriela said she was going to run a soap-making workshop. Here at last was my chance to learn! 

On a hot August day, a group of people gathered in the kitchen of the grand old manor house that Gabriela runs as a B&B with her partner, Luis, and there on the enormous stone-topped island lay all the ingredients needed for making soap. All three of them: olive oil , water, and sodium hydroxide. That was it. And twenty minutes later, the mysteries of soap-making had been revealed. 

A word about sodium hydroxide:

The base ingredients of soap are fat and a strong alkaline - either sodium hydroxide or potassium hydroxide. These alkaline substances can be very harmful if ingested, brought into contact with skin, or if the fumes are inhaled so when using them care needs to be taken.  I make bars of soap using sodium hydroxide which can easily be bought from hardware shops as its often used for cleaning drains and the like. For liquid soap, I believe potassium hydroxide is used in a slightly different process that I have yet to try.

Sodium hydroxide is reactive with other substances such as water and some metals so choose your containers wisely and add the sodium hydroxide to the water, never the other way around!

• Always wear rubber gloves, goggles, and a face mask and work in a well ventilated area.

• Know which materials react with lye (eg aluminium, zinc etc) when choosing a container or stirrer for your soap. A heatproof glass or pyrex bowl and plastic or glass stirrer are best to use. 

• It's important to use the correct ratio of sodium hydroxide to fat so no messing about with the recipe! It's also not recommended to substitute olive oil with another type of oil without first adjusting the lye and/or water ratios otherwise you might end up with a soap that's caustic and harsh on the skin. Luckily there are several handy online soap calculators that can make the necessary adjustments for you.

How to Make Soap:

What you'll need:

• Kitchen scales

• A glass or pyrex mixing bowl

• A saucepan

• A thermometer

• A plastic mixing spoon

• Moulds (muffin tins will do if you have nothing else to hand, but line them with cupcake papers if you don't want your tin ruined)

• PPE - gloves, goggles, and a mask

Ingredients:

• 116 grams of sodium hydroxide (NaOH, caustic soda) 

• 208 grams of water

• 908 grams of olive oil (you can use a herb infused olive oil, or other types of oil such as almond, coconut, sunflower although you may need to adjust the quantities)

• 3 teaspoons of and essential oil of your choice (optional)

• Natural colourants eg red or green clay, coffee grounds, cacao, cinnamon etc (optional)

• Dried flowers for decoration (optional)

Method:

Put the water into a heat resistant glass or pyrex bowl (DO NOT USE METAL!) and, wearing rubber gloves, goggles, and a mask, add the caustic soda and mix well with a plastic or wooden spoon. Be careful not to inhale the fumes or have any of the solution come into contact with your skin.

WARNING: Caustic soda must always be added to the water, and never the other way around!

The chemical reaction between the water and the sodium hydroxide causes the mixture to get hot. Leave it to cool down to 38 degrees, checking regularly with the thermometer.

Heat olive oil to 38 degrees. Oil heats fast and stays hot so keep a close eye on it. 

When both mixtures are at 38 degrees, add the oil to the sodium hydroxide and using the blender mix until smooth. Mix in any essential oils or colouring you want to use, then pour into the moulds. Decorate with dried flowers if you wish and leave to dry for 2-3 days. Carefully remove from the moulds and leave to cure for a month.