I enjoy making my own cleaning supplies, and one of my favorites has been homemade laundry detergent. For months I made detergent from a Fels Naptha bar, Borax, washing soda, and water. I calculated the cost for the recipe I used — about $1.88 for 3 gallons, enough for roughly 128 loads — and it cleaned very well. Recently I discovered a concentrated version called “laundry sauce.” It’s essentially the same ingredients but with far less water, so instead of several gallons you end up with just a couple of jars that still handle the same number of loads.
How to Make Laundry Sauce
Begin by grating a bar of Fels Naptha.
Bring 4 cups of water to a boil in a large pot. Add the grated Fels Naptha and let it melt over medium heat, stirring occasionally until fully dissolved.
Once the soap is melted, add 1 cup of Borax and 1 cup of washing soda. Continue cooking and stirring for about five minutes to ensure everything is well combined.
Remove the pot from heat and allow it to cool briefly. At this point, you can follow different methods for finishing the sauce; I chose to transfer the mixture into a blender rather than dividing it immediately into jars.
Let the mixture sit undisturbed for 3 to 4 hours. During this time it will separate into two layers: a thicker top layer and a more liquid bottom layer.
Note the 3–4 hour wait. If left too long the top layer can firm up more than desired, which may require extra scraping during blending. When blending, proceed slowly at first to avoid splashing; if the top layer is firm you may need to scrape it down a few times and pulse the blender until the mixture is uniform.
Once fully blended and smooth, divide the laundry sauce evenly between two mason jars using a rubber spatula or spoon. The final texture resembles a thick mayonnaise, so labeling the jars is a good idea to avoid confusion.
To use the laundry sauce, add one tablespoon per load. Because of its thickness, I hold the tablespoon under the running water in the washing machine to help it dissolve and distribute evenly.
I’ve used this laundry sauce for several loads and it remains effective while taking up far less storage space than liquid detergent. It’s economical, compact, and cleans well — a great option for homemade laundry care.
Note: I link this recipe when sharing in roundup posts and weekend features, as it’s a handy DIY project for anyone wanting to simplify their cleaning supplies.