The United States Department of Agriculture (USDA), separates beef into eight different grades. The top five are sold to the consumer as cuts of beef, while the three lowest grades are typically used only for processed and canned meats.
Quality beef is typically graded as USDA Choice and USDA Prime. The American system focuses on quality grades for tenderness, juiciness, and flavour, and yield grades for the amount of usable lean meat on the carcass.
‘Prime’ is considered by the USDA to be the highest quality cut of meat according to their grading system. ‘Choice’ is second in quality, with ‘Select’ being the third highest quality available from the USDA assessors. While there are five other grades of meat, they are typically reserved for industrial processes and often used in soups or ground into meat. It would be rare to find a steak under the ‘Select’ classification.
Australian beef grading, for Wagyu in particular, uses the AUS-MEAT Marbling (MB) system, which ranges from MB0 (no marbling) to MB9+ (extraordinary marbling), where the "plus" indicates extremely high levels, comparable to Japanese A5 grades. This scale, along with the Meat Standards Australia (MSA) system, considers factors beyond marbling, like fat content, distribution, and texture, to assess overall quality and eating experience.
The Japanese system is the most detailed. The grading of meat is managed by the JMGA (Japanese Meat Grading Association) Beef Carcass Grading Standard.
The overall grade consists of two grades: Yield Grade (designated by a letter) and Quality Grade (defined by a number).
Yield Grade measures the amount of usable meat on a carcass and ranges from A (the highest) to C (the lowest).
“A” usually means the cow was a full-blood Wagyu. “B” is usually a crossbred Wagyu. “C” is generally for Angus or Wholestain cattle.
Quality grade is calculated by evaluating four different factors:
1) Meat marbling
2) Meat colour and brightness
3) Meat firmness and texture
4) Fat colour, lustre, and quality.
Each factor is graded on a scale of 1 to 5, with 5 being the highest score.