BMS (Beef Marbling Standard)

The Beef Marbling Standard (BMS) is the numerical scale used by the Japanese Meat Grading Association to evaluate the density and distribution of intramuscular fat in beef. It ranges from 1 to 12, with 12 being the most heavily marbled beef on Earth.

BMS Scale breakdown: - BMS 1-2: Minimal marbling. Roughly equivalent to USDA Select. - BMS 3-4: Modest to moderate marbling. Equivalent to low-to-mid USDA Choice. - BMS 5-6: Good marbling. Upper USDA Choice to low Prime range. - BMS 7-8: Excellent marbling. Exceeds most USDA Prime. - BMS 9-10: Exceptional marbling. Far beyond anything in the USDA system. - BMS 11-12: The pinnacle. Meat appears predominantly white with thin red striations. Extraordinarily rare even in Japan.

I've evaluated thousands of carcasses and I can tell you — the jump from BMS 6 to BMS 9 is not a subtle difference. At BMS 9+, the beef takes on an almost custard-like quality when cooked. The fat renders internally at such a low temperature that the meat literally dissolves on your tongue.

Important context: BMS is only one component of the Japanese grading system. A carcass also receives scores for fat color, meat color, firmness/texture, and yield grade. The overall letter grade (A5, A4, etc.) is determined by the lowest score across all categories. So a BMS 11 carcass with below-standard fat color might grade A4, not A5.

For consumers, BMS is the single most important number when buying Japanese Wagyu. Always ask for the specific BMS score — "A5" alone tells you it's BMS 8-12, which is a significant range.