Things You'll Need
Bits of soap
How to Make Dry Hand Soap Powder. During the earlier days of our country, the frugal nature of the citizens would not allow for any type of waste. Making dry hand soap powder was something that grandma did with her leftover bits of soap. If you would like to know how to make dry hand soap like Grandma, follow the steps below.
Grate pieces of leftover soap bits. These are the last of the soap bars that always seem to end up melting near the drain of the shower.
Place the grated soap that you have flaked onto a baking dish. Glass is the best for the project. Put them in an oven that's set at the lowest possible temperature. If you're using a gas oven, the pilot may be enough to complete the drying process.
Check the flakes periodically. The amount of time that it takes to dry them will vary by not only the additives in the soap but the moisture that the soap has retained. Once you're satisfied that they're thoroughly dried, remove them from the oven and pan.
Place 12 ozs. of the soap bits, 9 ozs. of powdered borax, 6 ozs. of cornmeal and 1 1/8 ozs. of sodium perborate in a blender. Blend lightly and pulse until it's powdery.
Sift the mixture through a kitchen flour sifter. Repeat the process several times. Put the final mixture into a shaker. When needed, wet your hands and shake some dry hand soap onto them.
Experiment with a different recipe for powdered soap. Mix 3 ozs. of the soap bits that are grated, dried and pulverized. These must be hand pulverized since you are not using any cornmeal, and the soap will stick to the blender. Mix this with 7 ozs. of trisodium phosphate. Sift this mixture several times with a flour sifter.
Simplify it all. If you're not in the mood to chase down all the ingredients, grate bits of soap, dry them in the oven and pulverize.