Wagyu Beef Grades Marbling Science
Origin
Japan — Tajima cattle lineage documented Edo period; modern wagyu grading BMS system established 1975 by Japan Meat Grading Association
Description
Wagyu (和牛, Japanese beef) grading in Japan uses the Japan Meat Grading Association's BMS (Beef Marbling Score) system from 1-12 and a yield grade A-C. True wagyu breeds: Tajima-gyu (Hyogo Prefecture — produces Kobe beef), Omi-gyu (Shiga), Matsusaka-gyu (Mie), Yonezawa-gyu (Yamagata). The intramuscular fat (sashi) in wagyu has a different fatty acid composition than standard cattle — higher oleic acid content (similar to olive oil) with a lower melting point (25-30°C vs 40°C for regular beef fat). This means wagyu fat melts at body temperature, creating the characteristic rich, silky texture. BMS 10-12 (A5 grade) contains more fat by weight than protein in the leanest cuts.
The Thread
Flavour Context
Sweet, rich, buttery fat that melts at body temperature — beef umami with oleic acid creating olive oil-like silkiness