Tri-tip comes from the tensor fasciae latae muscle, nestled at the bottom of the sirloin subprimal. For decades, midwestern and east coast meatpackers ground this triangular piece into hamburger or dropped it into stew packages. In the 1950s, butchers in Santa Maria, California, began marketing it as a standalone roast, discovering that its loose grain structure and moderate fat cap allowed it to cook quickly while retaining exceptional juice.
A typical untrimmed tri-tip weighs between 2.5 and 4 pounds. It contains minimal connective collagen compared to chuck, but far more intramuscular marbling than top round. That balance makes it uniquely versatile. It behaves like a thick steak yet carves like a centerpiece roast. When selecting a cut, seek out a piece labeled USDA Choice or Prime with an intact fat cap trimmed to roughly one-quarter inch. That fat layer bastes the meat during oven roasting, insulating the leaner muscle underneath from drying out.
