Fresh eggs are gathered on automatic collection belts at the farm and stored in a cooler at about 7 ?C (45 ?F). The eggs are then delivered to a central processing plant, where they are washed, sanitized, and graded. Grading involves the sorting of eggs into size and quality categories using automated machines.?Flash candling?(passing the eggs over a strong light source) detects any abnormalities such as cracked eggs and eggs containing blood spots or other defects. Higher-grade eggs have a thick, upstanding white, an oval yolk, and a clean, smooth, unbroken shell.