Original Gravity

original gravity. (uh-rij'-[e]-nel grae'-vuh-d:ee)

    The specific gravity of the wort prior to fermentation at the temperature under consideration as compared to the density of water at 39 °F (4 °C), which is conventionally given as the value 1.000. It is a measure of the total amount of solids that are dissolved in the wort. Abbrev: OG. Syn: starting gravity; starting specific gravity; original wort gravity. See also: terminal gravity.