Osmolarity expresses the concentration of osmotically active particles in a solution as osmoles of solute per liter of solution. It determines the osmotic pressure that drives water across semi-permeable membranes, a force central to food preservation techniques such as brining, curing, and osmotic dehydration. In beverage and dairy formulation, osmolarity affects mouthfeel, stability, and how a product interacts with the body after consumption. Because volume shifts with temperature, osmolarity is slightly temperature-dependent, unlike osmolality. Food scientists measure it to predict microbial inhibition, control crystallization, and design products with intended physiological effects.