Japan enjoys a rich variety of four seasons. While at times these bring pleasant comfort, at others they bring intense weather that raises cattle to be healthy and strong. Rich sources of natural water from rivers and underground springs aid the healthy growth of pastures and cattle.
Cattle are fed a diet of grass, straw, and other roughage, as well as concentrated feed. They are also fed whole crop silage (WCS), in which entire straw bales are turned into silage. Rice straw is absolutely essential in creating the proper marbling and color of the meat. Heifers and pregnant cows are allowed to roam the fields freely in order to give birth to healthy calves.
A discussion of oleic acid and stearic acid is essential to understanding what gives Japanese Black its delicious taste. Japanese Black is known for having a higher proportion of fatty content than other meat. This quantity of fat is one factor responsible for the delicious flavor. However, it is not merely enough to have ample fat content; that fat must be largely composed of oleic acid and stearic acid.
Oleic acid and stearic acid are major contributors to the quality of Japanese Black wagyu. These acids are called unsaturated fatty acids, and they have a lower melting point than ordinary fats. The fat usually found in animals, like lard, remains in solid form even amidst hotter temperatures.
Unsaturated fatty acids, however, and in particular oleic acid and stearic acid, have a very low melting point. This means that when this meat is consumed, the fats break down with the first bite from body heat in the mouth, lending the meat a soft, melt-in-your-mouth texture.
Meat from Japanese Black heifers has a low melting point, making it suited to the Japanese shabu-shabu style of cooking, where the meat is passed briskly through boiling water.
In particular, Japanese Black heifers have a very high proportion on average of oleic and stearic acid -- as much as 80-90%. This means that certain premier brands of wagyu require their standards of quality to be based on heifers.
A certain quantity of oleic acid is found among animal fats; this acid is the major compound in olive oil. Stearic acid is also found in ample supply in blue-scaled fish like pilchard and sardines. In other words, oleic and stearic acids are healthy fats that are known to regulate the bloodstream.