To trim beef tenderloin, there are three steps that can be followed in any order desired. The first step is to remove as much fat as possible from the meat without damaging the tenderloin. The second step is to find and remove a long, uneven strip of tough meat known as the chain and, optionally, to remove a small piece of meat known as the ear, which interrupts the shape of the tenderloin. The final step involves removing a very tough sheet of tendon known as the silverskin. After this, what remains is the edible portion of beef tenderloin.
Before starting to trim beef tenderloin, it is important to have a very sharp knife and towels or napkins to keep the handle of the knife, and one's hands, dry to prevent accidents and leave the meat as intact as possible. Tenderloin has two ends, the larger of which is known as the butt; the thinner end is called the tail. Most cuts should begin at the thick end and move toward the tail, usually in short, controlled slices.
The first step to trim beef tenderloin is to remove visible fat from the surface. There will be several areas of fat that can be cut away, sometimes taking a small amount of edible meat with it. Most notably, there is a large area of fat just beneath the butt end of the tenderloin. Some fat cannot be removed from the meat without actually gouging the surface, so it is normal to have some areas of fat remaining.
Next, there is an area that is a different texture from the rest of the meat; this is known as the chain. The chain is a very tough, thin muscle that runs down the entire length of the tenderloin. Starting at the head, the top of the chain is firmly attached and might be difficult to separate; once it is loose, the rest of the chain can be pulled away with just the hands. On the tail end of the tenderloin, there might be a long piece of meat that seems to be loosely attached; this is called the ear and can be cut away from the tenderloin and saved for use later. These steps are not always performed by butchers that trim beef tenderloin.
The last step required to trim beef tenderloin is to remove the silverskin. This is a thick, translucent, smooth white sheet that covers most of one side of the tenderloin. It is inedible and can contract during cooking, bending the meat. It can be separated at one point with a sharp knife and then possibly pulled away with the fingers. If it is particularly tough, then a knife can be used to gently slice away small sections of the silverskin until it has been completely removed from the tenderloin.