Flat Iron Steak
The Flat Iron, is also known as the Top Blade or scientifically the infraspinatus. This is the second-most tender muscle in the entire carcass, second only to the Tenderloin/Filet Mignon (psoas major). The tenderness and juiciness of this muscle are superb. The cut also has robust, beefy flavor. Historically the top blade has been used for pot roast or as a cross cut steak from the Shoulder Clod.
Most consumers are not familiar with this cut but they love it once they taste it. The Flat Iron can be found on the menus of 1000s of restaurants across the country. Cooking times for this cut are approximately 25%% longer than steaks from middle meats. There are two reasons for this. First, the cut plumps up (thickens) during cooking and secondly, the red color is more intense due to a higher pigment content. To offset this, some restaurant operators flatten or tenderize it mechanically prior to cooking. Others apply a simple marinade (15%%) consisting of water, salt and spices.
In order to assure premium performance in this cut, the trimming procedure must include total removal of internal connective tissue. This tissue runs the entire length of the muscle and is very thick at one end. A good way of envisioning the trimming procedure of this cut is to think of it as removing the skin from a whole fish once the bones have been removed.
The flat iron steak is well marbled and is very juicy. It can be cooked to a higher degree of doneness (by temperature) and retain its tenderness versus other cuts. Because it has a higher degree of myoglobin (the red blood cells that give meat it's red color) it will look redder at a higher degree of doneness (by temperature) than most other cuts.