It's actually pretty easy to whip up a homemade dish detergent, and doing so not only helps you avoid plastic bottles, it also keeps questionable chemicals out of your kitchen. Few companies disclose which chemicals they use in their dish soaps and detergents, and many contain artificial fragrances containing volatile organic compounds that can steam off into your kitchen when your dishwasher runs.
So here are some ideas for eliminating, or at least drastically reducing, the amount of plastic trash you generate in cleaning your dishes, while also doing a lot to keep your indoor air clean:
Liquid soap can be made from scratch from oils and/or fats and lye, but it's a complicated multi-step process that usually starts with making bar soap and then turning that into liquid soap. For simplicity's sake, you can skip to the last step and make liquid soap from a premade bar. I bought a bar of plain, unscented soap at my local farmer's market. Look for a soap made without moisturizers or artificial fragrance. To be super-green, save the leftover slivers from bar soaps you use for hand washing and bathing. You can also purchase plain soap flakes online.
1 4-ounce bar soap OR 4 ounces plain soap flakes
8 cups water (or strained herbal tea, which adds a nice mild scent)
½ teaspoon essential oil (optional)
Grate the bar soap with a cheese grater (freezing the soap beforehand may make this easier) while you heat the water or tea in a large pot until it starts to steam. Take the pot off the stove, add the soap gratings and essential oil, if using, and mix well with a wire whisk or an immersion blender. Let sit for 8 to 12 hours. If the mixture is not completely uniform, mix it well again and let it sit for another 8 to 12 hours. Put your finished liquid soap into an empty wine bottle and top it with a metal pour spout (check your local restaurant supply or find these online) or buy yourself a classy glass cruet. Store any extras in a glass bottle or jug.
This liquid soap will not make suds like most commercial dishwashing liquids. That doesn’t mean it won't do a good job, just that it doesn’t contain the chemicals dish liquid manufacturers add to make it foam. Add ¼ cup or more of white vinegar as needed to your dishwater to help cut grease, especially if your water is hard.
You can also use this recipe as regular liquid hand soap. Add a teaspoon of honey to the recipe to prevent it from drying out your hands.