There are eight beef quality grades.
The grades are based on two main criteria: the degree of marbling (intramuscular fat) in the beef, and the maturity (estimated age of the animal at slaughter).
Some meat scientists object to the current scheme of USDA grading since it is not based on direct measurement of tenderness, although marbling and maturity are indicators of tenderness.
Most other countries’ beef grading systems mirror the US model, except for those in the European Union (EU).
The EU employs a grading scheme that emphasizes carcass shape and amount of fat covering instead of marbling and aging.
The differences in grading yield incompatible value judgments of beef value in the USA and the EU.
Most beef offered for sale in supermarkets in the US is graded US Choice or Select. Some upscale markets may offer U.S.Prime
US Prime beef is mostly sold to hotels and upscale restaurants, and usually marketed as such.
U.S. Prime – Highest in quality and intramuscular fat, limited supply. Currently, about 2.9% of carcasses grade as Prime.
U.S. Choice – High quality, widely available in foodservice industry and retail markets. Choice carcasses are 53.7% of the fed cattle total. The difference between Choice and Prime is largely due to the fat content in the beef. Prime typically has a higher fat content (more and well distributed intramuscular “marbling”) than Choice.
U.S. Select (formerly called U.S.Good) – lowest grade commonly sold at retail, acceptable quality, but is less juicy and tender due to leanness.
U.S. Standard – Lower quality, yet economical, lacking marbling.
U.S. Commercial – Low quality, lacking tenderness, produced from older animals.
Utility, Cutter, and Canner grade are primarily used by processors and canners.
Worth Watching Grading Video