Make your own dishwasher detergent as a natural alternative to premade detergents that may contain harsh chemicals you'd rather not use on your dishware. Most of the ingredients are available at grocery stores and department stores. Making your own detergent also costs less than most store-bought brands.
In a large bowl, mix one cup each of borax and washing soda, which is available in the detergent aisle at large grocery stores. Washing soda -- sodium carbonate -- is a stronger, inedible relative to baking soda -- sodium bicarbonate. Mix in 1/2 cup each of citric acid and sea salt or coarse kosher salt. Wear rubber gloves while working with the ingredients to prevent skin irritation if you have sensitive skin.
Pour the mixture into a large glass jar or container with an airtight with a lid; use a funnel if pouring out of the bowl neatly proves too difficult. Store the mixture with the lid intact on the container in a low-moisture area, as powdered citric acid clumps if exposed to moisture or humidity.
If you would rather not use borax for your homemade detergent, mix instead 1 1/2 cups each of powdered citric acid and washing soda. Add 1/2 cup each of baking soda and sea salt or kosher salt, mixing all the ingredients thoroughly. Store the detergent in an airtight container such as a glass jar with a lid.
Do-It-Yourself Dishwasher Gel
If you prefer a gel-based dishwasher detergent, add 2 cups of liquid castile soap to 1/2 cup of water in a saucepan. Pour in 1/2 cup distilled vinegar, as well as 1 teaspoon citric acid. Warm the ingredients over low heat, stirring until the castile soap dissolves. Once the liquid cools, pour it into an airtight container. Use 1 tablespoon for each dishwasher load.
For either the standard and borax-free dry recipes, use one tablespoon homemade detergent per load. Fill the rinse-aid reservoir on the dishwasher with white vinegar or lemon juice; either ingredient helps clear away soapy or greasy residues for a cleaner rinse. A rinse aid is optional for the gel version since it already contains vinegar.
Any homemade dry detergent that contains citric acid may get clumpy over time, even if kept in an airtight container in a non-humid environment. To help prevent clumps, place some uncooked rice in a paper coffee filter or unused, empty tea bag, stapling the paper or tea bag shut. Place the bag of rice atop the detergent. Another way around the clumping is to omit the citric acid from the original detergent mixture, adding in 1/2 to 1 teaspoon directly to each load in the detergent compartment along with your homemade detergent.