A hydrometer is a tool used to measure the weight of a liquid in relation to to water. This measurement is called the Specific Gravity (SG) of a liquid.
In home brewing we use a hydrometer to measure the Original Gravity (OG) and Final Gravity (FG) of our beer. These two measurements, and a little math, help us to determine when fermentation is complete and how to calculate the alcohol content of our brew. Pretty cool, eh? Continue reading