Depending on the country you purchase beef in, it might be considered under a different grading system, though many countries rate their beef by Japanese standards.
The Japanese system of grading is quite sophisticated, originally developed in 1988. This grading scale is defined with a letter for its overall yield, followed by a number based on its quality.
The letter – A, B, or C – is more significant to cattle farmers as it is a standard determining the overall yield once the cattle are butchered. Grade A is given to cuts that retain 72% of the overall yield or higher, whereas B is for yield percentages between 69 and 72%, and C is 68% and below.
After yield is measured and graded, much consideration is put into both the meat and fat’s overall quality. Authentic Wagyu is graded by the coloration, size, marbling content, and shape of this meat. These factors are added up to what is called a quality score.
These scales are graded on a Beef Marbling Standard (BMS) of 1-12, while the grade standards are scored from 1-5. A BMS of 1 means that there is no marbling present in the cut at all, while 12 means there is the highest amount of marbling possible present.