To make liquid laundry detergent, combine 1/3 to 1/2 cup of liquid Castile soap, 1/2 cup of washing soda and 1/2 cup of Borax in a 2-gallon bucket. Fill the bucket with hot water, and mix the detergent well before using.
Ivory or Fels-Naptha soap can be used in place of Castile soap to make liquid laundry detergent. To make the detergent with Fels-Naptha soap, grate the 2/3 of a bar of the soap with a cheese grater, and heat 12 cups of water in a large pan over low heat. Add the soap to the water, and mix constantly until the soap dissolves.
Pour the soap and water mixture into a 5-gallon bucket, and add 1 cup of washing soda and 1 cup of Borax to the mixture. Stir until the powders dissolve, and add an additional 2 gallons and 12 cups of water. Stir the detergent well before each use.
To make laundry detergent with Ivory soap, grate 1/4 bar of Ivory soap, and place a saucepan of water over low heat. Melt the soap in the hot water, stirring constantly, and pour the mixture into a 2-gallon bucket. Add 1/8 cup of Borax and 1/4 cup of washing soda, and stir to dissolve the powders. Add enough hot water to make 2 gallons of detergent, and stir well to combine.