Making Homemade Soap: Lavender & Calendula Cold-process Soap

I have made ‘handmade’ soap previously but have always used ‘melt and pour’ soap where you really just melt it, add your own colour and fragrance, and pour it into a mould to set. This time I tried making cold-process soap that makes it from scratch using a kit from Go Native that has all the ingredients, instructions and mould for Cold Process Loaf Soapmaking.

I always wanted to try making soap from scratch but never quite picked up the courage to do it previously as it uses a strong alkali solution of sodium hydroxide (called lye) that is very caustic. A work colleague told me that she makes soap every week and shares it with friends and family. When I asked her about the lye she said that she thinks of it like using boiling hot water: it burns if you splash it on yourself but you can wash it off and you use protective equipment and care to keep yourself safe. For lye you also need to work in a well ventilated space and preferably use a range hood or extractor fan to remove the fumes (only toxic for about 30 seconds when it is first mixed).

Lavender & Calendula Cold-process Soap

230g Coconut Oil
230g Shea Butter
230g Olive Oil, pomace
104g Sodium Hydroxide
250g Water
10g Calendula Petals
30ml Lavender Essential Oil

Step 1
Melt the solid coconut oil and shea butter gently in a stainless steel pot.
Add the olive oil, mix well and set aside to cool to 40°C.

Step 2
You must be exceedingly careful at all times: sodium hydroxide is a very dangerous chemical — in all its forms. See below for more details.
You must put on your safety glasses and rubber gloves and work in a well-ventilated area, preferably under an extractor fan.

Fill a heat proof container with 250g cold water.
Pour in the sodium hydroxide and stir with spatula until dissolved. It takes about 30 seconds.
Hold your breath and avert your eyes.
Set aside to cool to 40°C.

This mixture is now often called lye or lye water. It is still dangerous. Put it somewhere safe where no person or animal can touch it.

The chemical reaction is fascinating. The cold water turns to extremely hot water and toxic fumes are given off for about 30 secs.
If you splash your skin it will sting. Don’t panic. Dab the area with vinegar and/or flush with water for as long as it takes to take the sting away.

Step 3
When both the oils and lye are 40°C, put on your safety glasses and rubber gloves.
Pour the lye into the oils and stir continuously with a stick blender. Beware of splashing the soap mixture everywhere. Stop whisking often and give it a stir with a wooden or plastic/rubber spatula. Gradually the mixture will thicken. This is called saponification.

Step 4
When the soap mixture is the consistency of thin porridge, add the calendula petals (and colour if you wish). Continue to stir until these are well blended.
Add fragrance and blend in well. Continue to stir until the soap traces, ie, when some mixture is drizzled on top it doesn’t sink back in.

Step 5
Now pour into a silicon mould. If desired you can top it with mica powder and a few more calendula petals. Cover the mould with a piece of baking paper and then wrap it up in a couple of towels. Leave it alone for 24 hours. During this time the soap will heat up and then cool down.

24 hours later
Put your hand under the blanket to feel the container to make sure it is cold.
When it is cold, put on your rubber gloves, uncover and unmould. If unmoulding is difficult, put the mould in the freezer for 30 minutes then try again.
Cut the soap into bars with a kitchen knife or soap cutting blade if you have one.

Set the bars to dry out. Leave them for at least 3 weeks before using. A bonus is that they smell amazing and scent the room for that time.

NB: Sodium hydroxide, lye, lye water
This chemical is very caustic and must be treated with great caution at all times.
It will burn skin, blind eyes, remove paint and play havoc with everything it touches.
If it touches your skin, you will know. Your skin will sting. Dab with vinegar and/or flush with running water until the stinging stops. Keep it away from everyone, especially children and animals, at all times.
If you spill it in its dry form, put on your gloves and sweep it up. Dispose of it in your usual rubbish bag.
If you spill it in its lye (liquid) form, put on your rubber gloves and mop it up with towels or rags (the towels will become rags!) and dispose of it in your usual rubbish bag.