Here is the recipe I used for homemade laundry soap
1 (76 oz) box 20 Mule Team Borax (in the laundry aisle)
1 (55 oz) box Arm & Hammer Washing Soda (laundry aisle, next to the borax)
1 large bar Zote soap ( I got this from Amazon.com, you can also use a bar of Fels-Nappa also found in the laundry aisle. I picked Zote because it was pink )
1 (4#) box Arm & Hammer baking soda (store brand would be fine, found it in the baking aisle)
Grate the bar of soap. I used my food processor. The soap was very soft, so using a hand grater would easily work too. I didn't worry about 'contaminating' anything, its just soap. I dumped the borax and both sodas into a small rubbermaid container with a snap on lid. Then added the grated soap and stirred with a heavy plastic spoon. If you are doing this in a smaller container, you may want to add layers of the ingredients to make for easier mixing.
I also added a container of Purex crystals. Just so it would smell good. Honestly, I think they are a little over-powering so will probably skip this step next time. I did fill the empty purex container with some of my new detergent and use the lid to measure. half of a lid full got my clothes clean and fresh!
So far so good. I think it cleans well. We live on a farm and trust me, we get dirty!
It doesn't make suds so I am hoping it will be easier on our septic system and washer.
The best part? You only use 1 tablespoon for a load. (I used 2 tablespoons for Scott's super grungy barn clothes) this is going to last a long time!!
Edited: I read another recipe, just like this. Substitute a small box of Tide detergent for the grated bar of soap. Make it easier.