How is sake categorized?

Sake is categorized by how much the rice is polished away. They use a special milling machine to mill away the rice to remove excess protein and fat which rice contains more near the skin.
If the remaining ratio is less than 60%, it is categorized as Ginjo/premium and if it's less than 50%, it is categorized as Daiginjo/super premium. This remaining ratio is called "Seimai buai" in Japanese and listed on the back.
Light body sake: Daiginjo/super premium-pair with sashimi
Medium body sake: Ginjo/premium-pair with chicken, turkey
Full body sake: Junmai/regular -pair with beef or pork