How is the Yield Grade (denoted by letters A/B/C) determined?

Okay, no problem! Let's talk about what this Japanese Wagyu "Yield Grade" (A/B/C) is all about. I'll try to explain it like we're just chatting, so it's easy to understand.

Let's Talk About Japanese Wagyu "Yield Grade" (A/B/C)

Imagine you're buying a big watermelon. You definitely want one with thin skin, lots of flesh, and few seeds, right? That way, for the same price, you get more actual watermelon to eat.

The Japanese Wagyu Yield Grade is exactly that concept. It doesn't rate how tasty the meat is, but rather "how much sellable meat can be cut from this carcass" – what we often call "meat yield" or "dressing percentage".

This grade is mainly for slaughterhouses, meat wholesalers, and restaurant owners because it directly affects their costs and profits. An A-grade carcass means more marketable meat can be cut from it, with less waste (like excess fat, bones), making it naturally more cost-effective.

So, the A/B/C grade can be simply understood as:

Grade A: Above Standard (Excellent, very high meat yield!)
Grade B: Standard Level (Good, average meat yield)
Grade C: Below Standard (A bit of a loss, less sellable meat)

So... How Do Graders Calculate This Grade?

You might wonder, is the A/B/C just assigned by graders glancing at it? Of course not! There's a very precise, even somewhat complex, official formula behind it.

After the cattle is slaughtered, graders make a cut at a specific location (usually between the 6th and 7th ribs) and measure several key data points:

Ribeye Area (ロース芯面積)
- Simply put: This is the size of the cross-section of what we commonly call the "sirloin" or "ribeye" steak. This is one of the most valuable cuts on the carcass, so a larger area indicates higher potential meat yield.
Thickness of Brisket (バラの厚さ)
- Simply put: This is the thickness of the brisket cut. Graders measure this area because a thicker brisket also indicates a generally substantial amount of meat overall.
Thickness of Subcutaneous Fat (皮下脂肪の厚さ)
- Simply put: This is how thick the layer of fat is right under the skin. Most of this fat is trimmed away during processing, so it's considered "waste". Thicker fat means more gets trimmed, naturally lowering the lean meat yield.
Cold Carcass Weight (冷屠体重量)
- Simply put: This is the weight of the entire carcass after slaughter, bleeding, skinning, evisceration, and cooling in a cold room. This is the base weight used for calculation.

Graders plug these 4 measured values into an official formula specified by Japan's Ministry of Agriculture, Forestry and Fisheries (MAFF). This calculation results in an "Estimated Meat Yield Percentage".

How is A/B/C Determined After Calculation?

The percentage calculated by the formula directly corresponds to the A/B/C grade:

Grade A: Meat Yield 72% or higher
Grade B: Meat Yield 69% or higher, but less than 72%
Grade C: Meat Yield Less than 69%

So, this letter grade is a purely objective, mathematical result – very scientific.

A Very Important Point: A/B/C and 1-5 are Two Different Things!

This is where many people get confused. The "A5 Wagyu" we hear about most often is actually a combination of two different grades:

Yield Grade (A, B, C): Concerns "Quantity". It tells you how high the meat yield is from the carcass.
Meat Quality Grade (1, 2, 3, 4, 5): Concerns "Quality". This is what evaluates how tasty the meat is, primarily based on 4 aspects:
1. Beef Marbling (BMS) (what we call "marbling" or "fatty streaks")
2. Meat Color & Brightness
3. Meat Firmness & Texture
4. Fat Color, Luster, and Quality

Therefore, when we say A5 Wagyu, it means:

"A": Represents that the carcass has a very high meat yield, 72% or above.
"5": Represents that its meat quality – whether marbling, color, or taste – has reached the highest level, Grade 5.

Theoretically, C5 Wagyu also exists. This means the carcass has a lower meat yield (Grade C), but the quality of its meat (marbling, flavor, etc.) is top-tier Grade 5. This meat might taste just as delicious as A5, but for meat suppliers, less sellable meat can be cut from this carcass, making it more costly.

To Summarize

Yield Grade (A/B/C) is like evaluating a car's "Fuel Efficiency" – how far it can go on a tank of gas, representing efficiency and output.
Meat Quality Grade (1-5) is like evaluating the car's "Performance and Interior Quality" – how fast it accelerates, how comfortable the seats are, representing quality and experience.

Hope this explanation helps you understand what A5, B4, and other grades mean the next time you see them!