Spin the egg on a flat surface; a hard-boiled egg spins smoothly and quickly
Stop the spinning egg briefly with your finger, then release it; a hard-boiled egg starts spinning again more evenly
Shake the egg gently near your ear; a hard-boiled egg usually makes little or no sound
Check the shell after cooling; a hard-boiled egg often feels uniformly firm
Peel a small spot; a hard-boiled egg has a fully set white and yolk
Place the egg in water; a hard-boiled egg sinks and lies on its side or stands upright