Plato Hydrometers

The Balling Scale, aka Plato scale, is an empirically derived hydrometer scale to measure density of beer wort in terms of percentage of extract by weight. The scale expresses the density as the percentage of sucrose by weight, so a wort measured at 12° Balling-Plato has the same density as a water-sucrose solution containing 12% sucrose by weight, denoted as 12% Brix. It was developed in 1843 by Bohemian scientist Karl Balling as well as Simon Ack, and improved by German Fritz Plato. For the brewer, it has an advantage over specific gravity in that it expresses the measurement in terms of the amount of fermentable materials.