Liquid temperature detectors

Disclosed are devices and methods for measuring the temperature of a liquid in a container, the device either having a temperature sensor for measuring the temperature of the outer surface of the container, a probe for directly measuring the contents of the container, or an IR detector for measuring IR radiation passing, through, re-emitted by, and emitted by the container. The device may be in the form of a corkscrew, bottle opener, pen, or simple casing. The temperature reading may be outputted to the user audibly and/or visually, such as with an LCD display. In one embodiment, there are mounted a plurality of indicator lamps, each lamp representing a particular type of liquid, a control for selecting the type of liquid whose temperature is to be measured, an infrared detector, an output indicating to the user whether the temperature of the liquid is above or below a predetermined temperature range.