Soap flakes are usually sold in the laundry aisle at grocery stores. You can substitute soap shavings for store-bought flakes if you prefer.

Do not allow the mixture to come to a boil on the stove. If it starts to boil, reduce the heat. Stirring the mixture as it heats can help the soap melt more quickly.

You can substitute fresh lemon juice for the vinegar if you prefer. Both will help cut grease when you’re washing dishes. The amount of vinegar you should add to the soap depends on how thick the mixture is. If it is extremely thick, add approximately 2 tablespoons (30 ml) to help loosen it up. If the soap mixture is already liquidy, just add approximately 1 tablespoon (15 ml).

It’s often easier to transfer the soap from the pan to the dispenser with a funnel.

Stir the mixture as it’s heating to help the soap dissolve more quickly.

Washing soda is usually found in the laundry aisle of large grocery stores. If you can’t find it locally, you can order it from a variety of online stores.

If you’re adding extra washing soda, start by mixing in ¾ teaspoon (3 g) and letting the soap sit again. If it’s still not thick enough, mix in the washing soda in ½ teaspoon increments (2 g) until it’s the right consistency. If your soap has chunks or lumps, smooth it with a blender or an immersion blender.

You can use any essential oil that you like, but citrus oils, such as lemon, lime, and orange, are particularly effective in cutting grease. Juniper and lavender are also good options.

Borax is a natural mineral that’s ground down into a powder and used in cleaning products, such as dish soap and laundry detergent. You can find it with washing soda in the laundry aisle of most grocery markets. If you want your dish soap to have a scent, you can use a scented castile soap, such as lavender, peppermint, citrus, or tea tree.

If you want your soap to have a stronger scent, add 3 to 5 drops of your favorite essential oil, such as lavender or tea tree, and mix well. It’s okay if your soap is thin and liquidy. It will thicken up as it cools.