Verification of the quality of a liquid using a quality-sensing bottle cap

A quality-sensing bottle cap includes a sensor array having a plurality of conductive polymeric sensors. In some embodiments, each sensor is exposed within a mechanical chamber and is in electrical communication with an interrogation interface. The mechanical chamber is configured, in an inactive state, to be closed off from a headspace above a liquid contained in a bottle sealed with the quality-sensing bottle cap and configured, in an active state, to be open to the headspace. The sensor array may be tailored for a particular application, such as the detection of olive oil aroma. The sensor array may, for example, allow discrimination among olive oils of different qualities (e.g., extra virgin olive oil, lampante virgin olive oil, and refined olive oil), as well as discrimination among olive oils with negative attributes (e.g., olive oils with unpleasant aromatic notes, such as "fusty," "muddy sediment," "musty," and "rancid").