ELI5: Why does steak like ribeye and porterhouse generally taste better than the rest of the cow?

No, not at all. But these cuts are inherently tender when barely cooked at all, served rare, medium rare etc. They are quick to cook, three to ive minutes on a side, and therefore commonly used in the things we call "steaks." You left out the tenderloin. But that is far from the end of the story when it comes to what is tasty in the way of beef. Tender cuts tend to have a milder beef taste, tough cuts a much stronger one.

The thing that makes a muscle a tender cut vs a tough cut is the amount of use that muscle gets. The harder a muscle works the tougher it tends to be and therefore less useful as a steak. But tough cuts are far from useless.

The brisket is the front end suspention of an animal that can weigh a thousand pounds and they stand around using those muscles all day long. It would be impossible to eat a brisket grilled to a perfect medium rare, too tough to chew. But if you cook that thing at 200 degrees F for 12 hours in the smoke stream of a hardwood fire you've got Texas style Barbecue and it is drop dead tender and fantastic deliscious. A cow uses its tounge all day long every day, the heart too, tough as hell stuff but when simmered all day long in a flavorful slightly acidic liquid they make some of the best of thin sliced sandwich meats. All of the stuff that the grocery store meat market offers up as "stew beef" comes from cuts that require polonged cooking in liquid to make them tender enough to eat but a fine Beef Stew is a wondrous thing. Below that in quality is the stuff that is sold pretty much pre-chewed either as ground beef for burgers or processed into cured stuff like hot dogs or Salami. Back to that tenderloin.

The one muscle that is the tenderest of all, with a realativly mild taste as a result is the solus muscle, the tenderloin. It is quite tender and often paired up with the chef's finest sauces to make up for it's mild taste. The reason it is so tender is that, in animal headed for the meat market, it is scarcely used at all. Think of it as "the humping muscle" the one that rotate the pelvis to thust the penis forward. The castrated males, called steers, do get any use out of it, nor do the females headed for slaughter.

/r/explainlikeimfive Thread