We recieve many calls and emails here at Mr. Beer on how to use a hydrometer. Many of the hydrometer instructions can be confusing to newbies so I thought I would create this primer on the correct way to use a hydrometer and the explanation of specific gravity. Understanding Your Hydrometer: The hydrometer is a simple instrument that measures the weight (or gravity) of a liquid in relation to the weight of water. Because the relation of the gravity to water is specified (1.000), the resultin