Sodium carbonate - washing soda

Sodium carbonate (also known as washing soda or soda ash) has the chemical formula Na2CO3 and is the sodium salt of carbonic acid. It is obtained by calcining table salt. It is used in the production of glass, paper, and of course cleaning products. In homemade cleaners, it acts as an excellent water softener and effectively removes greasy stains from soiled fabrics.

Recipe for powdered laundry detergent:
1 bar of grated laundry soap
1 cup of washing soda
½ cup of borax
a few drops of essential or fragrance oil of your choice and to taste
(one cup is approximately 230 milliliters or 2.3 dcl; one tablespoon holds 15 ml)

Finely grate the soap and mix all the ingredients well. For lightly soiled laundry, add one heaped tablespoon; for more heavily soiled laundry, add two tablespoons of the powder. It also depends on water hardness, as harder water requires more powder. Experiment a few times until you find your optimal amount.