Food spoilage monitoring device

A lid for closing a container comprising

• a first part having an indentation adapted to receive a projection of a second part, the projection defining a cavity into which a spoilage monitoring device is received;
• the spoilage monitoring device comprising a reservoir containing a digestor fluid and a tray containing a digestible material, wherein the tray is sealed into the cavity to prevent escape of digestor fluid from the reservoir and wherein the tray has a base with a raised tactile pattern formed thereon and the digestible material covers the base with a smooth surface;
• and wherein an axial movement of the parts relative to each other causes irreversible activation of the device such that the digestor fluid is absorbed by the digestible material liquefying it over a period of time, whereupon the smooth surface is dissipated and a user is able to feel the raised tactile pattern.