A flexible lid may include a body including an upper portion connected approximately perpendicular to a cylindrical sidewall, the body defining a recess and inner wall constructed and arranged to facilitate the attachment of the flexible lid to a container. The flexible lid may include a plurality of ribs integrally formed with the cylindrical sidewall constructed and arranged to facilitate the elastic attachment of the approximately cylindrical sidewall to a container. A floating ball valve may be disposed within the upper portion being constructed and arranged to function as a one-way valve such that escape gases and fluids may escape the container while also preventing environmental fluids and contaminants from passing through the flexible lid into a container.
