A plug for a container for storing liquid includes a housing and an input end at an end of the housing, the input end having a liquid-impermeable membrane that allows gas flow to pass through. A first sensor is in a first sensor chamber inside the housing, the first sensor being configured to detect a smoke taint compound. A first filter is between the input end and the first sensor, where the first filter selectively allows phenols to pass through. A second sensor is in a second sensor chamber inside the housing, the second sensor being configured to detect a second substance different from the smoke taint compound. A second filter is between the input end and the second sensor, wherein the second filter selectively allows the second substance to pass through.