It's a simple way to check changes in concentration of a chemical in water when you're not worried about external contaminants (i.e. just water vapor or anticip

It's a simple way to check changes in concentration of a chemical in water when you're not worried about external contaminants (i.e. just water vapor or anticipated chemical reactions). For home brewers, measuring specific gravity at the start and end of your brew process is the simplest way to know how much alcohol is in your creation. For this you'd use a hydrometer: https://en.wikipedia.org/wiki/Hydrometer https://en.wikipedia.org/wiki/Hydrometer