Materials: 400 ml of water, 50 g of edible salt, 50 g of sugar, 2000 ml of waste edible oil, 240 g of sodium hydroxide, and 400 ml of alcohol with the concentration of 10%-20%.

Production process: firstly, add salt and sugar into water and stir evenly, then slowly pour sodium hydroxide solution into the mixed oil. After stirring for half an hour, add alcohol and continue stirring. Remember to stir slowly and then quickly. The more stirring, the better. The more uniform the mixing, the faster the reaction and the better the quality of the finished product. When it becomes sticky, you can put it in the mold, pour out the solid after one week, and then put it in the shade for more than three weeks, and the soap is finished.

In this way, the expired blending oil can be reused to protect the environment. If you are skilled in post-production, you can use various oil products with some flower liquid and food essential oil to make essential soap, which will add some fun to your craft.