I just finished making my first batch of homemade liquid laundry detergent.
1 Quart boiling water
1 Bar Fels-Naptha soap, grated
2 C Borax
2 C Baking Soda
2 Gallons water
Where I found the ingredients: I found Borax and a very large box of baking soda at Wal-Mart in the same aisle. Many recipes call for "Washing Soda," but I couldn't find it anywhere, and after much forum reading, it seemed that baking soda was a fine substitute. Fels-Naptha is an old-fashioned bar of soap intended for laundry and laundry stains. I found it at Ace Hardware and think it can probably be found at general hardware stores. It was $1.29 for a bar.
Boil Water in large pot, add grated Fels-Naptha and stir until dissolved.
Add to a large pail and add soda and borax, stir until dissolved
Add two gallons water
Use 1/4 cup for each load of laundry
Notes: The Fels bar didn't like to melt, so I used a wire whisk and that worked better. Grating the soap was no picnic, it probably took 15 minutes. Once all combined the complete mixture almost completely separated and thickened. Forums explained that the liquid mixture will gel and to give it a shake or stir before use. Also, on recommendation I added a few drops of Lavender Essential Oil.
I haven't tried a load yet, but will soon.