I’ve used this laundry detergent for about 3 years now, and I love it!
1/3 bar of fels-naptha soap
1/2 cup Borax
1/2 cup Washing Soda
1 gallon water
Grate 1/3 bar of soap, or *run it through a food-processor. Melt soap in 1 quart (4 cups) warm water over low heat. Stir until completely dissolved.
Add borax and washing soda. Continue stirring over low heat until mixture starts to thicken. Everything should be dissolved at this point.
Add 3 quarts (12 cups) tap water to a gallon-sized container. Add dissolved soap mixture to water and stir thoroughly. The detergent will begin to gel immediately. I’ve noticed some separation occurs after the detergent completely sets up. If this happens, just shake the container before use.
Use 1/4 cup for each load. This recipe will clean 64 loads of laundry.
*After shredding my fingers a few times trying to grate the soap, I decided to try using an old mini food processor I picked up at a yard sale for 50 cents. It works great! Cut the bar of soap into thirds, save two-thirds in a baggie for later use. Chop the remaining soap into small pieces and whirl in food processor until it is almost a powder-like consistency.