When you want a memorable meal for a special occasion, skip your supermarket's everyday "value" cuts and look for beef that's labeled "Choice" or "Prime." Those are the U.S. Department of Agriculture's top two grades, reserved for the tenderest and best-marbled of carcasses. Both represent meats of superlative quality. Prime is the higher of the two grades, but Choice sometimes represents superior value.
Better and Best
Think of the USDA's Select, Choice and Prime grades as "good," "better" and "best." They're differentiated by the age of the animal at the time of slaughter -- which directly affects tenderness -- and by the amount of fat within the muscle tissues, usually referred to as marbling. Graders look at the meat between the animal's 12th and 13th ribs, ranking the marbling as "abundant," and therefore Prime, or "moderate to small," which will bear the Choice label.
When you're trying to choose between Prime and Choice cuts of meat, use your judgment. The best Choice-graded steaks and roasts are marbled nearly as much as Prime, while others fall well short. Look closely at the respective cuts to decide how much difference you see, and whether it's worth the price premium. Remember also that premium grass-fed beef isn't usually USDA graded, because it's naturally lean and would therefore score artificially low on the standard grading system. This doesn't mean it's a poor product, simply that it's lower in fat than mainstream grain-fed beef.