Understanding Marbling in Beef

What is Marbling?

Marbling is a unique pattern of white intramuscular fat in meat that creates what is known as the "marbling effect." This intramuscular fat impacts the flavor, tenderness, and texture, especially in red meat. It is important to not get intramuscular and intermuscular fat mixed up. While the intramuscular fat provides tenderness and flavor to the meat, intermuscular fat does not not enhance the flavor and is usually removed from the meat. 

Grading Meat Marbling:

- In the U.S., Australia, and Japan, human graders are used to visually inspect the quality of meat. The amount and distribution of the white fat flecks in the meat is used to determine the meat's overall grade. 

- In the United States, the U.S.D.A has 8 grades that beef can be classified into. Prime, Choice, Select, Standard, Commercial, Utility, Cutter, and Canner. Meat graded Prime will have the highest levels of marbling and will be considered top of the line. Meat graded at the lowest levels, like utility, cutter, and canner, are most often used for ground beef.

What Factors Affect the Marbling in Meat?

The amount of marbling in meat is determined by a combination of factors:

• Breed - Some breeds have a natural tendency to be more marbled. Breeds such as the Kuroge-washu, which give us Wagyu beef,  have a higher quantity of intramuscular fat that produces higher levels of marbling and higher levels of healthy fats (higher in Omega-3's compared to Omega-6 fats). American Angus and Herefords are breeds also known to produce quality marbling. 
• Type of Feed - A cow's feed plays a vital role in the overall marbling and quality of meat that is produced. Cattle that are underfed, or fed an inferior feed, will not gain weight properly...marbling will disappear from the muscles quickly and can be difficult to restore if it has gone too far into decline. Cattle that consume a diet of grains often marble more easily than those whose food consists only of grass. However, cattle kept specifically on feedlots and fed grass pellets may not receive the exercise or nutrients needed to create the levels of marbling found in grass fed cattle that feed on open range and pastureland.
• Age at Slaughter - Age is an important factor when it comes to the quality of beef. As a general rule, young cattle, or Veal, will have less marbling due to the fact that intramuscular fat is the last to develop. This means that younger cattle will normally have less flavor and be less tender...older cattle may have less marbling as well due the loss of intramuscular muscle and fat as they age. Depending on how they are fed, cattle can be ready to butcher somewhere between 14-36 months of age.

The level of marbling in your meat will also be determined by it's location on the cattle. Areas of the cattle in which the muscle are used less, such as the loin, will produce more fat and therefore more marbling. Lean muscle, like in the legs and rump, produces less fat and less marbling. It is simple science.

 What makes Marbling Important?

Marbling is important because it is what makes your favorite steaks juicy and flavorful. It keeps them moist during cooking, so that natural juices don't evaporate in the pan like they would if there were no marbling at all! Overcooking will result with all of this fat being cooked away - leaving you with a dry, tough steak, not the juicy, tender steak you expect. 

How to judge marbling for yourself?

When shopping for or attempting to judge the quality of meat for yourself, as with anything, it takes time and practice. The more meat you buy and test out, the better you will get at being able to pick out the best cuts. If you are looking for higher quality meat, you need to look for finer marbling, which will produce smaller white flecks of fat more evenly distributed through the meat and give you the tenderness and juiciness that so many people love. Wagyu beef, like in the image just above, is known to have higher levels of marbling with more even distribution of intramuscular fat, making it one of the highest quality cuts of meat you can buy.

Meat with medium quality marbling will not produce the same tender and juicy flavor as meat with finer marbling. When the fat pieces become larger and less evenly spread throughout the meat, it becomes more difficult to properly cook the meat. The bigger the pieces of fat, the longer they will take to properly render, often resulting in an overcooked steak. This issue only becomes worse as the quality of marbling degrades and the fat becomes larger and even more unevenly spread. So be sure to keep this in mind when picking your next steak.