Homemade Laundry Soap

by Helen Prout

The cornerstone of most DIY laundry soap is 100% coconut oil soap and mine is no different. Unlike regular soap, which contains extra oils to leave your skin moisturised, laun- dry soap contains no superfat, as its job is to clean your clothes – not leave an oil residue on them! As with commercially prepared laundry detergents, it’s possible to make a liquid or powder version; I’ve opted to make a liquid version here.

There are a number of steps to making DIY laundry detergent. Firstly you need to make the laundry soap: once you have this, you will need to grate, melt and then mix it with some other ingredients, before storing it in a bucket for later use.

One of the main differences between using DIY and commercially produced laundry, is that it leaves my laundry simply smelling ‘clean’ – even though I have used essential oils, my washing comes out smelling of nothing at all, and personally I’m happy with that. I find that it works great for coloured clothes, but that whites need some extra help. Some good tips can be found at Apartment Therapy.

Borax is a mild alkali and is one of the main ingredients in many DIY cleaners.  Although borax is not considered to be a skin irritant, studies have shown it to be toxic if ingested in large amounts. You should always keep it in a secure location, away from children. Borax is well known for its effectiveness at stain removal – An article in the UK Telegraph recommends soaking whites in 2 tablespoons of borax, dissolved in water, for 15 minutes, before continuing to wash as normal.


Table 1: Equipment & Ingredients for 100% Coconut Soap
For you:

Safety glasses / goggles; Gloves; Apron;

Long sleeved top

Soap-making Utensils: Stainless steel (or enamel) saucepan;

Silicone baking mould(s); Electric stick blender; Jam thermometer; Digital scales;

Tall sturdy plastic jug; Rubber/spatula; Plastic chopstick (optional);

Clingfilm (optional)

Soap-making ingredients:

  • 1000 g coconut oil (100% of oils);
  • 375 g filtered water;

180 g Sodium hydroxide/lye (0% lye) Optional: 1-2 ounces essential oils e.g. lavender; rosemary; tea tree oil.

Laundry Detergent ingredients: 140 g / 5 oz laundry soap;

1 cup borax (Borax Decahydrate); 1 cup washing soda (available in supermarket in the laundry aisle); 6 litres filtered water.

Note: If you change the type or quantity of oils used in the recipe, you must run the recipe through a lye calculator.


Soap-making instructions:

  1. Assemble your ingredients and soap moulds and put on your safety clothing.
  2. Weigh out your water and pour it into a tall sturdy plastic jug.
  3. Weigh your lye into a container.
  4. 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 100°F or 37°C (measure using jam thermometer).
  5. Weigh the coconut oil and add them to your saucepan.  Heat the oils until they reach 37°C, and then turn off the heat.
  6. When the lye and oils are approximately both at 37°C, slowly add the lye to the sauce- pan of oil. Alternate 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 (approximately 3-5 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.
  7. If using essential oils add to the soap batter now. Pour the batter into sturdy plastic jug.
  8. Pour the soap into a heavy duty, flexible, silicone loaf or individual moulds. Cover the soaps with cling film before placing out of sight, in a dry location.
  9. Unmould the soap after a couple of days, and place in a dry location to cure for 4 weeks.
  10. Many soap makers don’t wash the containers until the next day as most of the lye will have been neutralised by then. Use good gloves and hot water.


Liquid laundry detergent instructions:

  1. Grate 140g / 5 ounces of laundry soap.
  2. Bring 2 litres of water to boil in a large Add  grated laundry soap  and stir gently, until soap has dissolved.
  3. Add borax and washing powder, stirring until they dissolve.
  4. Pour into a large bucket with a lid; add a further 4 litres of water and stir. Leave to rest overnight.
  5. Before using, shake or stir the bucket. Use ¼ cup per load.
  6. If you live in a hard water area, you might like to use distilled white vinegar in place of fabric conditioner – ¼ – ½ cup per load. A few drops of essential oil can be added if desired.


Step 1: Add lye (sodium hydroxide) to cool fil- tered water. Mix well with a plastic chopstick or similar.

Step 2: Melt coconut oil, then remove from heat. Leave to cool to 100°F or 37°C.


Step 3: When your oils and lye are roughly the same temperature, add the lye water to the oils. Stick blend in short bursts. When the soap batter has thickened, add your essential oils if using them.

Continue to use the stick blender in short bursts, to incorporate the essential oils, and until the batter reaches trace (picture shows soap at heavy trace).


Step 4: Transfer soap batter into a sturdy plastic jug. Pour into your moulds. Place the soaps in a dry place, out of sight of prying fingers, for 1-2 days.  Cover freshly poured soaps, with cling film if there are small people in the house. Un-mould and leave to cure for 4 weeks.

Step 5: Grate soap: store until needed.


Step 6: Put 2 litres of water in a large saucepan. Add 5 oz grated laundry soap, and stir over heat until melted.

Add borax and washing soda, and stir until dissolved. Pour into a large bucket, with 4 extra litres of water and stir.   Leave to rest overnight.

Can be used immediately.sn6

Step 7: Stir / shake the bucket before using. Use ¼ cup per standard wash. Use ¼ – ½ cup white wine vinegar per load as fabric softener, particularly in hard water areas.