We started making our own dishwasher soap this week. We’ve tried it several times before and were not happy with the results, but this time we like it.
Keep in mind we do have very, very soft water. I don’t know how this would work in hard water.
We mentioned the recent change is commercial dishwasher soaps in this post. In the comments, somebody told us where we could get trisodium phosphate, which is the missing ingredient.
We already have Borax and Washing Soda on hand all the time because we make our own laundry soap. We picked up Savogran 10621 Trisodium Phosphate (TSP) at the hardware store while we were in town working on our Rattery.
First we washed a couple loads of dishes using 1 tablespoon each washing soda and borax and 1 teaspoon of TSP. Then Pip got tired of that and just mixed up a big jar of the stuff- one part TSP to 3 parts each washing soda and borax. We keep this under the sink in an old coconut oil jar with the lid tightly shut. We use just a little more than two tablespoons per load, and have been quite satisfied with the results.
Updated to note: If you have very hard water you can try adding salt to the mixture to help soften the water, or use your regular storebought dishwasher detergent and add a teaspoon of tsp to each load to boost the cleansing power.
You can also add white vinegar to the rinse cup to make dishes sparkle.