Eggs shrink in corn syrup due to osmosis. Osmosis is the process by which water passes into and out of cells through a semi-permeable membrane.
Water enters into and out of tissues via osmosis. During osmosis, water moves into or out of a cell through the cell's semi-permeable membrane. This membrane is essential in allowing vital materials into cells without permitting unwanted or dangerous materials through. During osmosis, water flows from an area of higher concentration to an area of lower concentration. Osmosis is easily observable using materials found in most kitchens: raw eggs, vinegar, water and corn syrup. An egg shell is too hard and impermeable to demonstrate osmosis but soaking an egg in vinegar for two days dissolves the shell, leaving the soft, permeable membrane. Soaking some of these naked eggs in water and some in corn syrup provides a very visible demonstration of osmosis. After soaking overnight, the corn syrup egg is smaller in size. This is because there is comparatively more water inside the egg than in the corn syrup, so water flows out of the egg into the syrup. The opposite occurs with the egg in water. The water egg is larger because there is more water outside the egg, so it flows into the egg.