A quick search online will show you that there's no shortage of homemade laundry soap recipes: Here's one from The Simple Dollar. And we've got 10 more at Money Talks News. But below is one that seems to work pretty well. You'll need:
• 4 cups of water.
• 1/3 bar of cheap soap, grated.
• 1/2 cup washing soda (not baking soda).
• 1/2 cup of Borax (20 Mule Team).
• 5-gallon bucket for mixing.
• 3 gallons of water.
First, mix the grated soap in a saucepan with 4 cups of water, and heat on low until the soap is completely dissolved. Add hot water/soap mixture to 3 gallons of water in the 5-gallon bucket, stir in the washing soda and Borax, and continue stirring until thickened. Let the mix sit for 24 hours, and voila! Homemade laundry detergent.
Of course, who'd post a recipe without trying it out first? I made and washed several loads of clothes with the homemade detergent. And I, like many before me who've traveled this road, couldn't tell the difference between store-bought and homemade.
Total cost per load? In the neighborhood of 2 cents. Store-bought detergent, depending on what you buy and where you buy it, can cost about 20 cents per load -- 10 times more.