Good question

Dr. Doreen Kaiser: »Many hand disinfectants largely consist of ethanol, which can be extracted from the residue (pomace) that is left over from apple juice production. Apple pomace is rich in carbohydrates such as sucrose, starch, and cellulose, all of which are ideal starting materials for fermentation into ethanol. To do so, the pomace is mixed with water, yeast, and cellulases and then blended in a fermenter for two days at 37 degrees Celsius. The resulting ethanolic solution is then distilled. The remaining residue is fed back into the fermentation process. This makes the research approach that my team and I are using sustainable in two ways: It enables ethanol to be produced from a waste material and it doesn’t generate any new waste.«

Photo: TU Bergakademie Freiberg / D. Müller