Japan (Hyogo Kobe, Mie Matsusaka, Shiga Omi as three historic centres; JMGA grading system established 1988)
Japanese wagyu beef is graded by two systems: the yield grade (A, B, or C — the ratio of meat to carcass weight) and the quality grade (1–5, covering marbling, meat colour, fat colour, and firmness/texture). The marbling assessment uses the Beef Marbling Standard (BMS) scale from 1–12, with most commercial wagyu grading at BMS 3–7 and the most prized beef reaching BMS 10–12. At BMS 12, the fat-to-muscle ratio is so extreme that the meat appears almost white — individual strands of lean muscle embedded in a matrix of intramuscular fat. The fat in wagyu has a specific fatty acid profile high in oleic acid (a monounsaturated fat), which gives it a lower melt point (25–30°C) compared to standard beef fat — meaning wagyu fat melts at body temperature, producing the legendary 'melts in the mouth' sensation. The three most renowned wagyu breeds are Tajima (producing Kobe beef from Hyogo Prefecture), Matsusaka (from Mie Prefecture), and Omi (from Shiga Prefecture). Kobe beef is the most internationally recognised, with strict criteria: Tajima cattle, BMS 6 minimum (typically 8+), and raised within Hyogo Prefecture. The A5 designation (yield A, quality 5) with BMS 10–12 represents the market apex.
Deeply rich, fatty, melt-at-temperature; umami from inosinic acid; the butter-like fat is the dominant flavour experience
{"BMS 1–12 marbling scale: higher BMS = more intramuscular fat; premium starts at BMS 6+","Oleic acid fat composition: low melt point (25–30°C) — fat melts at body/eating temperature","A5 designation: yield grade A + quality grade 5 — requires high BMS, correct colour, firm texture","Three supreme breeds: Tajima (Kobe), Matsusaka (Mie), Omi (Shiga) — each with distinct character","Kobe criteria: Tajima cattle, BMS 6+ minimum, raised in Hyogo Prefecture with registered ranch"}
{"Rest wagyu at room temperature 30 minutes before cooking — the low-melt-point fat won't survive cold","Cast iron or teppan iron at very high heat: fast sear, thin cut, rest immediately","BMS 8+ wagyu is often better enjoyed as yakiniku thin slices than as a thick steak","The rendered wagyu tallow from cooking can be used to cook other ingredients — extraordinary richness"}
{"Cooking A5 wagyu the same as standard beef — the high fat content means it needs half the cooking time","Overcooking — wagyu fat renders aggressively; medium-rare maximum; medium is already too much","Overseasoning — high-BMS wagyu needs only salt and pepper; complex marinades obscure the fat character","Thick cuts for high-BMS wagyu — thin is better; the fat-to-lean ratio is too high for thick-cut steaks"}
Tsuji Shizuo, Japanese Cooking: A Simple Art