Grab a clean air-tight jar or container to store the mixtures. Other necessary items include bar soap, washing soda and baking soda.
To make enough detergent to wash 42 to 62 loads, grate three 5 ounce bars of soap such as castile soap, Fels Naptha or Zote. Cut the bars into small pieces, and finely grate them into a powder using a food processor. Alternatively, use a box grater to grate each bar into small flakes.
Add an equal amount of both washing soda and baking soda, which performs the same function as borax. When making a large batch of detergent with three bars of soap, add 6 cups each washing soda and baking soda. When making a smaller batch, add 1 cup each for every 1 cup of grated soap.
Store the homemade mixture in the air-tight container. Add 2 to 3 tablespoons of homemade detergent for every load of laundry. Optionally, add essential oil such as lemon oil as a degreaser, or tea tree oil, which helps disinfect laundry.