The recipe should say 15 quarts of water (or about 3 and 1/2 gallons.)

You can use a 5 gallon bucket as Laurie mentions above and tripple the recipe. Use about 1/4 cup in each full wash load. Use less for a smaller load. This amount can be adjusted based on how dirty the clothes are. I live in the south and the dirt here is bright red and stains everything so I tend to use more than someone in another part of the country might use. Also, I tend to make my mixture more concentrated because of our soil (and dogs) so you could add more water than I mentioned above as well. You can experiement to see what amount of water works best for you. But 5 quarts is a good place to start.

Another good reason to separate the powder mixture from the grated soap (until you need to mix more laundry soap) is because a 50/50 combination of borax and washing soda can be used in the dishwasher. (I wouldn’t use the powder mixture with oxy clean.) I keep this 50/50 mixture in the old vinegar containers. I have been using this in my dishwasher in place of dishwashing liquid for 2 years. Put vinegar in the rinse container – I have never used commercial rinse agents – always vinegar. My dishes sparkle!

Also, I have a GE dishwasher and the model was recalled last year for having some wires short out. I was told that the rinse container leaks if overfilled and the commercial rinse agents have been corroding the wires. So when I got the recall letter, I called to make an apt to have the repair man come out and fix my dishwasher. When he open my machine he asked me if I ever use the rinse container because it looked brand new. I told him I use it all the time but it has only ever held vinegar. He told me he never heard of using vinegar but my wires still looked new and had no corrosion on them. (I asked him to make the fix anyway since he was already here.) He told me he was going to recommed that everyone use vinegar as a rinse agent from now on. By the way, my machine was 9 years old at the time. My mother always used vinegar in the rinse container and it never occured to me to use anything else.

Good luck with your laundry soap creation!

I have not had much luck with powdered detergent. I have hard water as well (sigh). But, I have made this liquid version several times and think that it is really good. It doesn’t call for Oxyclean. However, I will add that separately for an extra boost for the whites. I also add some orange or lemon essential oil for extra grease cutting action and a lovely scent.

For a fabric softener I add the essential oils to the vinegar (softener, rinse agent). I just put it in a Downy ball. Essential Oils can be purchased other places besides the health food store for a lot less money.

Homemade Laundry Detergent
1 Bar Fels Naptha (soap found in the detergent aisle)
1 ½ cups Borax (Mule Team Borax found in the detergent aisle)
1 ½ cups Washing Soda (Arm & Hammer product found in the detergent aisle)
5 Gallon Bucket

Grate the soap and put it in a sauce pan. Add 12 cups water and heat on medium until the soap melts. Add the Washing Soda and Borax and stir until dissolved. Remove from heat. Pour 8 cups of hot water into the 5 gallon bucket. Now add the soap mixture and stir. Add 2 Gallons of water and stir. Let the soap sit for 24 hours, stirring periodically with a whisk, and it will gel. This laundry soap will not suds much, but it is cleaning. You can add essential oils for fragrance and extra cleaning power.