Boil 1 litre of water
Bring 1l of water to the boil in a saucepan, then stop cooking.
Add the ingredients
Remove from the heat and add 5 tablespoons of Marseille soap and 5 teaspoons of soda crystals.
Mix
Mix until smooth.
Add a second litre of water
Blend again.
Transfer to a bottle
Finish by pouring the lye into a bottle using a funnel.
Strong odours: add 4 tablespoons of bicarbonate of soda. It neutralises acids, deodorises and removes stains from clothes.
White detergent: add 2 tablespoons of sodium percarbonate to the detergent compartment.
Shake the can before each use, as liquid detergent tends to set when left to stand.