What instrument is used to measure the specific gravity (or relative density) of liquids such as beer and wine?
Beer measurement measure the density once the fermentation is completed, and to use these two data points in an empirical formula which estimates the alcohol content or strength of the beer. The most common method measuring the density of a liquid is with a hydrometer; hydrometers can be calibrated with a number of scales. A common scale is that of specific gravity (SG); that is to say the density of a liquid relative to the density of pure water (at a standard temperature). Specific gravity can also be measured by a pycnometer or oscillating U-tube electronic meter. Water has a SG of
Relative density both sample and reference vary from industry to industry. In British brewing practice the specific gravity as specified above is multiplied by 1000. Specific gravity is commonly used in industry as a simple means of obtaining information about the concentration of solutions of various materials such as brines, sugar solutions (syrups, juices, honeys, brewers wort, must, etc.) and acids Relative density ("RD") or specific gravity ("SG") is a dimensionless quantity, as it is the ratio of either densities or weights where "RD" is relative density, "ρ" is the density of the substance being measured, and "ρ" is the density of