Make your own laundry detergent from soap scraps

Zero waste goals: Reuse, rinse, repeat! 

We’ve all been there: There’s almost none of your bar of soap left, just a slim wafer of your treasured creation that’s getting tricky to use, liable to break into even smaller pieces if you so much as look at it the wrong way. So what do you do with it? While tossing those last bits of soap might seem like too little waste to worry over, we like to do everything we can to reduce waste. It all adds up! So, we’re sharing one of our favourite ways to reuse your soap leftovers: our DIY laundry soap recipe. This homemade laundry soap is good for you, your clothes, and the planet, and lets you to save a bit of cash too. All you need is a few ingredients that you already have on hand!

Without further ado, here’s how you can turn those soap scraps into your very own laundry detergent that will leave your clothes clean and delicately scented.

How to make your own laundry soap  

Ingredients

• 822 g (86.9%) water
• 70 g (7.4%) baking soda
• 47.4 g (5%) soap scraps, grated fine
• 6.6 g (0.7%) cotton aromatic essence

Tools

• Small stainless steel bowl 
• Silicone spatula
• Scale, accurate to 0.1 g 
• Large saucepan or pot  
• Hot plate or stove element
• Funnel
• Bottle (1 L) with a push-pull lid to facilitate pouring

Good to know!

• If you don’t have soap scraps, you can use any solid soap you have on hand, whether they’re intended for body or household use, without altering the above quantities. However, there are a few things to keep in mind.
  • For a concentrated, multi-purpose laundry soap opt for Marseille laundry soap.
  • African black soap is an excellent natural stain remover. If you use it in this recipe, we strongly recommend reducing it to a powder with a mortar and pestle before adding it to the water.
  • Aleppo soap is another excellent stain remover that is particularly effective against sweat stains, make-up stains, and oily stains. 
  • We advise against using olive oil Marseille soap or black soap paste in this recipe. Both are very oily soaps that may stain your clothes. 
• Keep in mind that some soaps will melt more quickly or slowly than others, so your choice of soap make affect how long it will take you to make this DIY detergent. 
• We chose cotton aromatic essence for its lovely “fresh laundry” scent. You can omit it if you’d prefer an unscented laundry soap or replace it with the aromatic essence or essential oil of your choosing. True lavender, sweet orange, or lemon essential oil are particularly good options for homemade laundry soap. 

Steps to follow

1. Prepare and disinfect your equipment and workspace.
2. Heat 822 g of water in a large saucepan or pot. As the water heats, grate your leftover soap scraps into thin shavings into the small bowl.
3. Add the soap scraps to the water when hot (it doesn’t need to be boiling). Stir until the soap scraps have completely melted.
4. Remove the pot from the heat and wait until the mixture has fully cooled, about a couple hours. Once the mixture is just warm, add the baking soda and aromatic essence. Mix well until homogeneous.
5. Use a funnel to transfer your DIY laundry detergent to the bottle.
6. Leave for another 24 hours before using it for the first time. 

Use and conservation

Pour about 200 ml of your laundry soap into the detergent compartment or directly into the drum of your laundry machine. You may need to adjust the quantity depending on your machine’s capacity or for an especially soiled load. Shake your DIY laundry detergent well before each use.

When made in optimal sanitary conditions, it will keep for about six months.