What is glycerine, and why bother talking about it? We use full fat, whole oil to make our soap, bar and liquid. This method of soap making, is very old fashioned, even ancient, takes a long time and a lot of skill, and produces the mildest soap, otherwise know as the best quality. So technically, our soap contains naturally retained glycerin.
Glycerin is an ingredient frequently found in soaps of all kinds. It's been sold to consumers as a beneficial ingredient, sometimes found in pretty pricey body care products. It's also found in food and supplements.
Glycerin is a by product of making biodiesel fuel. Natural glycerin is produced from recycled oil usually from fast food fryers (aka "vegetable oil"), and transesterorized. In simple terms, this process uses a strong base solution to separate the esters (the greasy part) from the protein (the glycerin). The ester is then further processed into biodiesel and the glycerin is sold in it's crude form, which needs to be cleaned of all the starches and food particles.This process is very similar to plastic recycling.
As a soap maker, I know this cleaning process is way more work that it's worth to get an inferior product that has NO emollient properties. Emollient qualities are softening and soothing to skin. Glycerin has lubricating qualities, which is very different. In other words, glycerin soap will make your skin dry instead of soft, since it lacks emollient qualities, but any lather produced will be nice and slippery. Totally not worth the effort, to get a drying soap that will leave your skin in need of cream immediately. As an industrial cleaner, lubrication is very useful, but not for skin.
All surfactants, ie: soap or detergent, make water, the universal solvent, wetter. This increases it's cleaning power, and can creates drying conditions. By leaving in the emollient part of the oil in equation, this counteracts the drying effect, making a sort after experience.
Most glycerin soap on the market is made with a commercially made glycerin, either produced from commercially grown, and probably genetically modified soybeans or made synthetically from propylene (a fossil fuel byproduct). It then is put through an alcohol extraction process. For glycerin tinctures, the alcohol is removed. For glycerin soaps, the alcohol is retained, giving them the clear look in appearance.
All in all, full fat, minimally processed fruit and seed oils are emollient and lubricating, which provides the best bathing experience for excellent personal hygiene.