Knights of the Mashing Fork

Since Plato is the percentage weight of sugar in solution and this percentage doesn't vary with temperature, it isn't necessary to mention temperature when talking about Plato measurements. However, the specific gravity of a solution varies with temperature making it necessary (and accurate) to always specify the temperature when expressing SG. In the absence of a temperature for a SG reading the standard calibration temperature of 68°F (20°C) can be assumed, however, many of the hydrometers available to homebrewers are still calibrated to the older 60°F (15.6°C) standard.