As an experienced sommelier and brewer, I can confidently say that higher specific gravity does not necessarily mean heavier. Specific gravity is a measure of the density of a liquid compared to the density of water, and it is influenced by various factors including temperature, pressure, and the composition of the liquid.
To understand this concept better, let's delve into the specifics. Specific gravity is defined as the ratio of the density of a substance to the density of water at a specific temperature and pressure. The density of water is conventionally taken as 1 gram per cubic centimeter (g/cm³) at standard temperature and pressure (STP). Therefore, the specific gravity of water is 1 by definition.
When we talk about liquids that are lighter or heavier than water, we are referring to their specific gravity values relative to water. Liquids with a specific gravity less than 1 are lighter than water, while those with a specific gravity greater than 1 are heavier.
However, it is important to note that specific gravity is not an absolute measure of weight or mass. It is a comparison of densities. For example, if we have two liquids with different specific gravities, the one with a higher specific gravity does not necessarily have a higher mass or weight.
In the context of brewing, specific gravity is commonly used to measure the concentration of sugars in a solution, such as wort or must. During fermentation, yeast consumes these sugars and produces alcohol, resulting in a change in specific gravity. Brewers use a hydrometer to measure specific gravity and monitor the progress of fermentation.
In my experience as a brewer, I have encountered various situations where higher specific gravity does not always mean a heavier liquid. For instance, when brewing a high-alcohol beer, the specific gravity may increase due to the presence of more dissolved sugars, resulting in a denser liquid. However, the alcohol produced during fermentation is actually lighter than water, so the overall weight of the liquid may not increase proportionally with the increase in specific gravity.
It is worth mentioning that specific gravity is temperature-dependent, and most values found in the literature refer to STP conditions. Changes in temperature can affect the density of a liquid, and consequently, its specific gravity. Therefore, when comparing specific gravities of liquids, it is essential to ensure that the measurements are taken at the same temperature.
To summarize, higher specific gravity does not necessarily mean heavier. Specific gravity is a measure of density relative to water, and liquids with specific gravities greater than 1 are considered heavier than water. However, specific gravity is not an absolute measure of weight or mass, and other factors such as temperature and composition can influence the overall weight of a liquid.