When we were synthesizing biodiesel using the waste oil from our school cafeteria, glycerol is the by-product. Since we did not want to dump this by-product into the waste bottle. We decided to use glycerol to make glycerin soap! Glycerin soap is a kind of soap which is useful for people with sensitive, easily irritated skin because it prevents skin dryness with its moisturizing properties.

Clear, amber color with thick texture glycerol we collected from waste oil.

Making Glycerin soap with Glycerol is not hard, but have to spend long time on heating up the ingredients. Below is the simplified procedure. It takes longer time to wait on heating (total of more than 1 hour) than the actual steps.

To be creative when we were adding the food dye, we decided to separate our glycerin mixture into two portions and each portion is added in different color. We was hoping to make a double layer soap, more like a double layer jello.

But when we poured it into the mold, two color got mixed together. And because the green color soap is so dark that it was not translucent, the orange portion “swallow” into the green portion.

See, it became a completely green soap… with bubbles on top.

After a week of waiting, we finally retrieve the soap, although it solidified, it much more like a jello-looking texture rather than solid piece of soap. It feels very moist and easy to break. In terms of its scents, it smells very similar to the essence oil we added in with a little touch of the vegetable oil smell.

In our class, weirdly, no one has successfully make a harden soap, some of the samples are jello-like and some did not solidify at all. We have no idea why this happened. Or maybe, we should look into the factor of turning glycerol produced from waste food oil into jello-looking texture of soap. We mind have invented a new kind of soap product!