Cellulose paper is a low-cost, flexible and biodegradable material that is ideally suited for the fabrication of near zero-cost sensors using high-volume printing methods. We have recently discovered that the intrinsic properties of cellulose as a highly hygroscopic biopolymer enable measuring gaseous analytes in a fundamentally new way. This new method of sensing gases allows detecting volatiles formed by the degradation of protein rich food products to measure food quality electrically. In this talk, Dr Guder will tell the story of paper-based electrical gas sensors (PEGS), their application in monitoring food spoilage and its future as a commercial solution to reduce food waste.