What property of fat and gravy juice allows them to be separated?

Fat and gravy juice can be separated due to their different densities and solubilities. Fat is less dense than the water-based gravy juice, causing it to rise to the top when left to sit. Additionally, fat is hydrophobic, meaning it does not mix with water, allowing for easy separation through skimming or using a fat separator. This physical property of fat makes it distinct from the aqueous components of gravy.