Rib Eye Wagyu, Japanese Kagoshima, BMS 10 A5

It is one of the most important and sought-after specialty cuts of beef, and is the tender “heart” of the ribeye. This premium cut of meat comes from between the 6th and 12th thoracic vertebrae.
When the ribeye is deboned, it yields a clean, oval cut of meat, the highest-quality steak, made up of two distinct muscles. It has a round, eye-like shape, hence its name, “ribeye.” It is exceptionally flavorful and tender thanks to its excellent fat distribution.

The history of Wagyu, then, began sometime in the late 19th century, when Emperor Meiji the Great regained power. From then on, Japan began to develop and transform from an isolated, feudal state into an industrializing superpower. With the restoration of imperial rule, a period of reform (Westernization) began in the country; Japanese customs and eating habits were changing. The ban on eating meat was lifted, and beef became part of Japanese cuisine. After 1868, as many Japanese became familiar with European and North American customs and everyday practices, eating beef became fashionable in the major cities. Encouraging beef consumption can be seen as part of the new regime's efforts to reshape the Japanese physique in a way that would make it more appealing in Western eyes, thereby facilitating Japan's entry into the ranks of countries whose average height was greater than that of the Japanese. To promote this goal, the government supported beef production and consumption. In 1871, it abolished the hereditary monopoly on meat production held by certain groups, and in 1872 it publicized both the emperor's position and the essay by thinker Fukuzawa Yukichi, “On Eating Meat,” as well as discussions on the subject among intellectuals, while promoting literary depictions of new ways of life. Thus, although Wagyu beef was developed and is raised in Japan, its incorporation into Japanese cuisine is, in fact, striking evidence of Western influence on Japanese customs, marking a significant turning point in Japanese history. 

In the 1880s, the Japanese decided to import animals from European cattle breeds and crossbreed them with Japanese cattle. In this way, the old working breeds developed into beef breeds. Several cattle breeds emerged from these crosses and still dominate Japan's beef trade today. However, only four of them are truly Wagyu breeds:

Japanese Black | The Japanese Black breed, whose meat is prized for its intense marbling. Since 90% of Wagyu cattle come from the Japanese Black breed, when people say “Wagyu,” they usually mean Japanese Black cattle. 
Japanese Brown | The Japanese Brown breed, a leaner, healthier cattle breed known for the mild flavor of its meat. 
Japanese Shorthorn | Japanese Shorthorn. Although also lean, Japanese Shorthorn beef is rich in inosinic acid and glutamic acid, two valuable acids that give it a more savory flavor. 
Japanese Polled | Japanese Polled: Like Brown and Shorthorn, Japanese Polled beef is lean and renowned for its more pleasant texture and rich, meaty flavor.

In the beginning, there was a black cow
Everything you need to know about Wagyu beef, especially Kobe beef  
“Wagyu” refers to any cattle raised in Japan or … in the Japanese style. In a loose translation, Wagyu means “Japanese cattle” (“Wa” means Japanese or Japanese-style, and “gyu” means cow or cattle in general). Put simply, “Wagyu” means “Japanese cow.” For Wagyu beef to be classified as Kobe, it must come from a very special member of the Wagyu breed, called Tajima-Gyu, raised under strict protocols in Hyogo Prefecture.  As Wagyu beef was often transported from Kobe to Yokohama—the commercial port in the Tokyo metropolitan area—it became highly prized by the foreigners living there. Its fans are also responsible for the slogan: “What other, Kobe beef!” 

But what makes Wagyu stand out from other types of cattle? And what makes Kobe beef so special that it often fetches the highest prices per kilo on the market? 
Ranchers who raise Wagyu cattle take exceptional care of them. They feed them milk until they are 3 months old. After three months, the calves are fed a mixture of grass, rice straw, and grains (corn, soybeans, and wheat). Kobe cattle are fed the same ration as all other Wagyu, but each farm varies the feed it gives its cattle slightly. In addition to corn or cornmeal, which is essential, they add oats, wheat, barley, soybeans, and even sugarcane silage or cacao nibs (fragments of the seeds inside the cacao fruit). Most animals also eat straw and hay, as they would in their natural habitats. It is worth noting that in recent years, two ranchers, one in Japan and one in the Netherlands, have adopted a different ration enriched with a tasty, digestible, and safe paste made from pure olive pulp, derived from roasted olive mill "waste." 

It is sometimes said that farmers massage their cattle to reduce muscle tension caused by cramped spaces.  
There are many myths surrounding Wagyu farming. It is said that they live in spa-like conditions, are fed “gourmet” food, are massaged with beer, and listen to classical music to help them relax. Although none of these myths has been debunked, that does not mean they are the norm. Producers follow very strict rearing guidelines, and some have indeed devised special methods that allow Wagyu to live leisurely, peaceful lives. They may listen to music, but it is not essential. What is certain is that the calm, leisurely lives of these cattle help increase the proportion of their intramuscular fat (marbling) and contribute to its unique distribution, which makes Wagyu beef so delicious and sought-after. Its “marbling”—the fine, white streaks of fat that melt as the meat cooks—helps it stay tender, juicy, and therefore flavorful. And because its fat’s melting point is lower than the average temperature of the human body, it melts pleasantly in the mouth. 

Part of its appeal is its aroma, a unique, sweet coconut scent. A relatively recent study in the Journal of Agricultural & Food Chemistry identified sixteen compounds that give it this distinctive aroma, ten of which are directly associated with the meat. The strongest evidence, however, comes from compounds derived from fatty acids.  The excess fat, its distribution, and the different composition of the fatty acids are due, on the one hand, to a genetic trait of this particular cattle breed—and also to their diet, which allows their intramuscular fat to reach 30 – 40 % of the muscle’s volume—and, on the other hand, to calves being raised until they are 30 months old.  

Marbling: The defining characteristic of Wagyu  
The result of these breeding methods, combined with longer fattening periods, is what gives Wagyu meat its exceptional flavor. Marbling gives Wagyu a better taste. Its fat melts at a lower temperature than that of any other cattle breed, resulting in a rich, buttery flavor not found in meat from other breeds. This fat is unsaturated and rich in omega-3 and omega-6 fatty acids, which means marbling not only makes it tastier, but healthier, too. Despite the breed’s genetically increased predisposition to forming intramuscular fat, Wagyu also produces a high proportion of unsaturated fats such as omega-3 fatty acids. These balance the corresponding proportion of omega-6 fatty acids and thus help reduce bad cholesterol and combat heart disease. 

Wagyu beef quality grading 
Another very important factor determining Wagyu quality is its grade. In some specialty butcher shops or on the menus of high-end steakhouses, you’ll usually see an A5 label. This is the grade it received from members of the Japan Meat Grading Association. Grades marked with letters from A to C refer to the yield of high-quality meat from each cow. A is the highest yield grade and C the lowest. Each letter is followed by a number (from 1-5), which indicates the quality grade: 5 is excellent, 4 good, 3 average, 2 below average, and 1 poor.  
The grading is based on four criteria:  
1. The marbling (the distribution of intramuscular fat in the meat) 
2. The color of the meat, in relation to its brightness 
3. The firmness and texture of the meat  
4. The color, in relation to the sheen and quality of the fat  

As for the «Sashi» grades (i.e., marbling, in Japanese), there is also a further assessment, the Beef Marble Score (BMS), with a scale from 1-12. 
According to the BMS, exceptional intramuscular fat is rated between 8-12, good between 5-7, medium between 3-4, the next-lowest level at 2, and the lowest at 1. So A5 is the highest-quality Japanese Wagyu, and therefore the most expensive. The best score an A5 could receive is A5-12, although this is extremely rare. Understanding how this grading system works can help you buy or order the meat you want at a price that suits your budget. 
All these details help explain, to some extent, why in countries such as the United States, the price of the finest Wagyu steaks easily exceeds $300.  
What’s more, a (live) Wagyu cow can cost as much as $30,000. In 2002, a Wagyu cow sold in Japan for around $400,000. It was a record and remains the highest price ever paid for such a cow. 

What about Wagyu burgers?  
Is it really worth ordering a Wagyu burger? I’d say probably not. The whole appeal of Wagyu beef lies in its distinctive texture, excellent marbling, and tenderness. So, if the meat is ground and made into patties or burgers, it will certainly be tender, but the difference in taste compared with any other (regular) burger will be small to barely noticeable.