Wagyu is a breed of Japanese cattle that were originally used in agriculture, these cattle were selected for their physical endurance. The selection favoured animals who contained the most intramuscular fat. This is where ‘marbling’ comes from. This intramuscular fat provided an easily available energy source.
‘Kobe beef’ and ‘Wagyu’ are often exchanged synonymously, this is incorrect. Kobe beef refers to a particular strain of Wagyu called ‘Tajima-Gyu’ which is raised in Hyogo. Hyogo’s capital is Kobe. In other words, Kobe beef is Wagyu but not all Wagyu is Kobe beef.
Wagyu melts in your mouth and is rich in flavour. This is largely due to the marbling content of the meat. Marbling (intramuscular fat/ IMF) is the white fat that appears as streaks or flecks that are intertwined in the red meat of the steak. These areas of fat give the beef its soft texture and provide the rich flavour of the meat. Intramuscular fat should not be confused with the thick white layer of fat that surrounds the outside of the steak. Although both of these are fat, intramuscular fat (IMF)/marbling is different. IMF is comprised of monosaturated fats (good fats). It is packed with essential fatty acids (Omegas 3, 6 and 9) – the same ones that are found in olive oil and salmon. Marbling is not ‘chewy’ like the fat that encompasses a steak on the outside. Marbling gives Wagyu its desirable silky, soft texture. Lastly, marbling also melts at room temperature and while you cook it. This spreads flavour throughout the meat while keeping it tender and juicy.
Live Wagyu are divided into 5 categories. F1, F2 and F3 classified animals are termed ‘crossbred’ they have a genetic makeup of 50%-87% Wagyu. A ‘purebred’ Wagyu is an F4 animal. This is an animal that has greater than 93% (+5%) Wagyu genetic content. Lastly, there is Wagyu whose genetic makeup is 100% Wagyu. This is a Fullblood Wagyu. It is important to understand the classifications of Wagyu, as an F5 Wagyu has the greatest marbling in its meat, F4 has more marbling than F3 and so on. The closer an animal is to ‘purebred’ or then otherwise if the animal is ‘fullblood’, the higher the quality of meat is and the more expensive it becomes. Therefore, wagyu prices can vary depending on the marbling score.