Trussing and Tying

• In most cases, you're likely to encounter butcher's string on larger cuts such as roasts. There are several reasons to tie or "truss" a roast, but one of the most common is simply to hold the meat together for cooking. Meat cutters often remove a large bone, a seam of fat, a strip of gristle or tough connective tissue or even a small group of muscles from the larger roast. This leaves a large gap in the roast, and the remaining portions often spread out flat when left to their own devices. By rolling and tying the roast, the butcher ensures it will cook as a single, solid piece of meat.

Finding Some Consistency

• In a few cases, roasts are trussed even when they already consist of one continuous group of muscles. In those cases, an oblong or flattened roast such as a ribeye might be trussed tightly to give it a cylindrical shape. This shape, with its round cross-section, makes it easier to ensure a consistent degree of doneness throughout the roast. It also makes for neater and more symmetrical slices, which look better on your plate.

Sorry, I'm Stuffed

• For showier entrees and festive meals, your butcher might also prepare stuffed roasts that require tying. This is more common with pork, lamb or veal, but certainly isn't unknown with beef. For example, at one edge of the tender ribeye roast is a separate muscle called the cap. The seam of fat joining the two can be cut away and replaced with a tasty filling such as spinach or mushrooms, then tied into place. When cooked, the filling makes a flavorful -- and sometimes colorful -- addition to the roast.

Smaller Cuts

• Although you'll find string more often on large cuts, it does show up occasionally on steaks or medallions as well. In some cases, as with a roast, it's to keep the steak together after a piece of bone or gristle has been trimmed out. With a bone-in rib steak, your butcher might tie the steak to the bone to hold it in place and give it a better shape when cooked. Sometimes you might even find tenderloin medallions made up of two smaller pieces of the fillet, tied together to make a single portion. In each case, if you find a single-portion cut tied up with butcher's twine, you should leave the string in place when you cook the beef.