Here's a video about USDA grades of beef and what to look for when choosing fresh meat online.
Regardless of their quality grade, some cuts of meat are naturally more tender than others. Cuts from the less-used muscles along the back of the animal — the rib and loin sections — will always be more tender than those from the more active muscles such as the shoulder, flank, and leg.
Since the most tender cuts make up only a small proportion of a beef or lamb carcass, they are in greatest demand and usually command a higher price than other cuts of gourmet steak or lamb.
Each USDA beef quality grade is a measure of a distinct level of quality — and it takes eight grades to span the range. They are USDA Prime Beef, USDA Choice, Select, Standard, Commercial, Utility, Cutter, and Canner.
USDA Prime, Choice, Select, and Standard grades come from younger beef. The highest grade, USDA Prime, is used mostly by hotels and restaurants, but a small amount is sold at retail markets. The grade most widely sold at retail is the USDA Choice Steaks. However, consumer preference for leaner beef has increased the popularity of the Select grade of beef. Select grade can now be found at most meat counters.
Standard and Commercial grade beef is frequently sold as ungraded or as "brand-name" meat.
The three lower grades — USDA Utility, Cutter, and Canner — are seldom, if ever, sold at retail, but are used instead to make ground beef and manufactured meat items such as frankfurters.
Following are photographs of rib steaks in the top three beef grades, together with a description of the level of quality that can be expected in each of these grades of beef.
USDA Prime: USDA Prime Beef is the ultimate in tenderness, juiciness, and flavor. It has abundant marbling — flecks of fat within the lean — which enhances both flavor and juiciness. Prime roasts and steaks are unexcelled for dry-heat cooking (roasting and broiling).
USDA Choice: USDA Choice Steaks have less marbling than USDA Prime Beef, but are still of very high quality. Choice roasts and steaks from the loin and rib will be very tender, juicy, and flavorful, and they are, like Prime grade beef, suited to dry-heat cooking. Many of the less tender steak cuts, such as those from the rump, round, and blade chuck, can also be cooked with dry heat.
USDA Select: Select grade beef is very uniform in quality and somewhat leaner than the higher grades of premium steak. It is fairly tender, but, because it has less marbling, it may lack some of the juiciness and flavor of the higher grades. Only the tender steak cuts should be cooked with dry heat. Other cuts should be marinated before cooking or cooked with moisture to obtain maximum tenderness and flavor.
Lamb is produced from animals less than a year old. Since the quality of lamb varies according to the age of the animal, it is advisable to buy lamb that has been USDA-graded.
USDA Prime: Prime grade lamb is very high in tenderness, juiciness, and flavor. It has moderate marbling, which enhances both flavor and juiciness. Prime chops and roasts are excellent for dry-heat cooking (broiling and roasting).
USDA Choice: Choice grade lamb has slightly less marbling than Prime, but still is of very high quality. Choice chops and roasts also are very tender, juicy, and flavorful, and are also suited to dry-heat cooking. Lower grades of lamb and mutton (USDA Good, Utility, and Cull) are seldom marked with the grade if sold at retail.
Most cuts of USDA Prime and Choice lamb — including shoulder cuts — are tender and can be oven-roasted, broiled, or pan-broiled. A leg of lamb graded Choice or Prime, for example, is delectable when oven roasted.
The less tender cuts — the breast, riblets, neck, and shank — can be braised slowly to make excellent (and tender) lamb dishes.
Meat from older sheep is called yearling mutton or mutton and, if it is graded, these words will be stamped on the meat along with the shield-shaped grade mark. Grades for yearling mutton and mutton are the same as for lamb, except that mutton does not qualify for the Prime grade and the Cull grade applies only to mutton.
Like lamb, pork is generally produced from young animals and is, therefore, less variable in tenderness than beef. However, there is another reason why pork is less variable. Producers have responded to consumer demand by actually changing their feeding and management programs. They've even changed the genetic makeup of their breeding stock to consistently produce leaner carcasses. Also, most visible fat is trimmed off at the processing plant. Because of these changes, today's fresh pork products have considerably less fat than they did just a decade ago.
Because of this consistency, USDA grades for pork reflect only two levels of quality: Acceptable and Unacceptable. Acceptable quality pork is also graded for yield, i.e., the yield ratio of lean to waste. Unacceptable quality pork — which includes meat that is soft and watery — is graded U.S. Utility.
When buying pork, look for cuts with a relatively small amount of fat over the outside and with meat that is firm and grayish-pink color. For best flavor and tenderness, the meat should have a small amount of marbling.
The Versatility of Pork:
Pork's consistency makes it suitable for a variety of cooking styles. However, like beef and lamb, the cut affects the cooking method. Following are some of the more popular pork cuts and suggested methods of cooking:
Pork chops come in a variety of cuts: center loin, rib chops, sirloin chops, boneless, or bone-in. They can be prepared by pan broiling, grilling, baking, braising, or sauteing. Thin chops (1/4 - 3/8 inch) are best sauteed. Boneless chops cook more quickly than bone-in chops.
Ribs are available as spare ribs, back ribs, and country-style ribs. Spare ribs come from the belly portion, while back ribs and country-style ribs come from the pork loin. All three styles can be braised or roasted in the oven or on the barbecue grill. Slow cooking yields the most tender and flavorful results.
Tenderloins are considered to be the most tender and tasty cut of pork. Extremely lean, pork tenderloins can be roasted whole, cut into cubes for kabobs or into strips for stir-fry, and sliced for scaloppine or medallions.
Properly wrapped meat cuts, frozen at 0 °F or lower, will maintain their quality for several months. This varies, however, with the kind of meat.
The following table shows a range within which you can store meat with reasonable expectation that it will maintain its quality. Meats can be kept safely frozen for longer periods than indicated, but they are apt to lose quality.