Castile soap making

Soap

Making soap really is fun and you can find all sorts of interesting things to use as soap moulds around the house. The soap does make great gifts and your friends will be fascinated that you have made it yourself and tend to have it on display instead of actually using it. I make lots and use some of it in and old soap shaker for washing the dishes.

I find it easier to have two sinks side by side because then you can have hot and cold water baths. The reason for this is that the caustic soda will need cooling down as will the oil if you have over-heated it. Often you will need to empty one of the cold water baths and put some hot water in because the oil can go below the required temperature in the one second you take your eyes off it.

Pomace olive oil is the last pressing of the olives and the lowest grade olive oil. It is not normally found in supermarkets but can be found in food wholesalers.

Equipment

  • Newspapers or old towels
  • Rubber gloves
  • Scales
  • 3 jugs. One for the olive oil, one for the water and one for the caustic soda
  • Long-handled wooden, stainless or plastic spoon
  • Old woollen blanket
  • Mould with lid
  • Stainless ladle
  • Stainless stock pot
  • 2 kitchen thermometers
  • Apron or protective clothing
  • Rubber or plastic spatula

Safety

It is irresponsible to allow small children around when soap-making because they are unpredictable creatures and might end up getting hurt by the caustic soda.

The first and most important thing you need to realise is how harmful and potentially dangerous caustic soda is. It will burn anything it comes into contact with, i.e. your skin, counter top, walls and the floor. Either in granulated or liquid form it will burn and strip the dye out of fabric and even eat holes in it – it isn’t a bad paint or varnish stripper. If you get caustic soda on your hands it will feel slimy and make your skin crack and peel and handling soaps that are under six weeks old will have the same effect. If caustic soda does come in contact with anything copious amounts of water will dilute it eventually.

Caustic soda is also called sodium hydroxide or lye. When you add cold water to it the temperature rises to approx 90°C /194°F in a minute. The next most important thing to remember is to always add the water to the caustic soda, not the caustic soda to the water. Caustic soda can normally be bought from a hardware shop and is most often found in the drain-cleaning area of a hardware shop. Don’t use other drain cleaners because they often contain other substances and you don’t want these in your soap. It is normally sold in a granulated form. Now that you are rightly terrified of caustic soda we can begin.

Handling caustic soda

  • Protect your work surfaces with either newspaper or old towels.
  • Any plastic jug used for mixing caustic soda needs to be dishwasher proof. If it isn’t then perform the following test to see if it will be suitable. Place the jug in your sink and fill with boiling water. Test the handle to see if it is weakened. The jug shouldn’t become flexible or melt. If it does, don’t use that jug but find another. This jug should only be used for this purpose.
  • Rubber gloves are a must to protect your hands from getting burnt. They must still be used when touching the soap during the six-week curing process.
  • Caustic soda can corrode metals so remove any jewellery that might be at risk.
  • NEVER inhale the fumes from the caustic soda. This is most prevalent after the water has been added. Turn your head to the side. It is always a temptation to inhale the aroma after the soap has been scented but all you will get is a lungful of the fumes. This can be injurious to your lungs.
  • Never leave oils or fats unattended when heating as they are flammable substances and could catch fire. If a fire does occur inside the pot slide the lid across the top as opposed to plonking it down on top, which could force the flames out the side of the pot and catch your hands or curtains.
  • Store the curing soaps out of the way of children and animals. The caustic soda can still burn them. Rats and mice will eat cured or uncured soaps. Our dog used to eat soap made from animal fats.

Olive Oil Castile Soap

This soap originates from Castile in Spain and is off-white in colour, very hard, long lasting, accepts additives very well, exceptionally mild, moulds and mills well, may be re-melted or milled when moist or dry, lathers quickly with plenty of medium-sized bubbles and trailings are difficult to see.

  • 1.5 L pomace olive oil
  • 200 g caustic soda
  • 625 ml cold water

Cover all surfaces and put on the rubber gloves. Weigh the caustic soda and put in the jug. Measure out the cold water in another jug.

Pour the water into the lye, not the other way around as it can explode. Stir with the spoon and put one of the thermometers into the solution to monitor the temperature, which should shoot up to 90°C/194°F. When all the caustic soda has dissolved, the jug can be put in a cold water bath to cool to 38°C/100°F. If there is too much water in the sink the jug will fall over. Keep a thermometer in the jug so you can see the temperature easily and remove if it is getting cold too quickly. To reheat the caustic soda solution if too cold put in a hot water bath. Tap water will be hot enough.

After you have done this heat the oil slowly. The aim is to have both the oil and the caustic soda at the same temperature at the same time 35–38°C/95–101°F. This is where the hot and cold water baths come in handy for jiggling the temperatures of either the caustic soda or the oils.

When they are at the same temperatures at the same time, pour the caustic soda into the oil slowly stirring all the time.

Keep stirring gently until what is known as trailings appear. Trailings are lines of soap that appear on the surface much like melted chocolate dribbled on the top of melted chocolate in a pot. Take your spoon out of the soap and drizzle a line on top of the soap in the pot. If they stay there you are ready to go. Even a small amount is okay as they can be hard to see.

Stirring can take from 15 minutes to an hour so make sure you aren’t in a hurry. If after an hour you still can’t see them just carry on as if you can. The soap should still be warm when you stop stirring.

Pour the soap into the mould using a spatula to scrape the sides of the pot and put these scrapings in too.

Place the lid on the mould, wrap in the blanket and leave in a warm place, undisturbed, for 48 hours. To make the wrapping in the blanket easier I have the blanket under the mould and in its place before pouring the soap into the mould.

The soap must cool slowly or else the oil and caustic soda will separate.

After 48 hours unwrap the mould and remove the lid. The soap will still be soft to the touch. Remember the soap is still very caustic so wear rubber gloves. Have a look at the bottom and sides of the mould and if you see any signs of liquid or curdling leave it – I will discuss this in the trouble shooting section.

If the soap is still very soft leave the lid off, exposing it to the air for the day. When the surface is finger-impression hard pull the sides of the mould away from the soap and turn the mould upside down over a sink, tub or plastic-covered surface. Press the bottom of the mould to release the soap. Don’t use newspaper or cardboard because the soap can absorb colours from these.

Leave the soap in one block overnight. To cut into bars the next day you will need a ruler and a knife to score on the surface, marking the bar sizes you would like. When you have scored out the bar size, heat a long-bladed knife in a jug of hot water and cut along the lines. Voila! Bars of soap. Told you it was easy.

Now the bars of soap need to cure for between a month and six weeks. I use old plastic fridge shelves. The types that are a rack not a solid shelf because there needs to be airflow under and between the bars of soap. If I am making big batches and I run out of plastic ones I use old ones from ovens with an old tea towel on top so the soap doesn’t come in contact with the metal. Put them somewhere away from children, animals, rats and mice.