I remember my aunt making iced tea for a family picnic. She brewed one huge, super-strong pot and one pot of plain water. She then mixed them until the taste was just right.
She was performing a classic chemistry trick called dilution. She was trying to find the isotonic point—the boring scientific name for “when two solutions have the same strength.” It is the Goldilocks zone of mixing.
If you have ever added too much water to soup and then added a bouillon cube, you have done this. You are trying to make the soup’s saltiness equal to the saltiness you prefer in your mind.
