Once I noticed this I was very curious. There has to be a reason.
Some tougher, pot-roastable cuts of meat used to have a bone in the middle of them; tying keeps the meet neatly bunched together after removal of the bone. Some pot roasts didn’t have a bone, but the tying disguises the butcher’s sloppy cutting job. Absent either of the two reasons above, the long cooking of a pot roast makes it tender and fragile, and the tying keeps it in a neat chunk.
Mmm, pot roast…
To keep it from running away. Woohoo! Post number 100!
Why is everybody looking at me that way?
It’s okay as long as the pot roast is a consenting adult.
There is no cut of meat called pot roast. All it is, is a method of cooking. You take a cheap cut of meat, usually chuck, and cook it in liquid. Why would it need to be tied?
The tied pot roast I am most familiar with is a “cross-rib” roast. It is rolled into a cylinder, because if it was not, it would be flat like a brisket… this would cause it to cook more quickly, but also to loose juices. Other tied roasts include prime rib (AKA standing rib), crown rib (that’s the one made from a pork loin with the rib bones arranged in a circle and pointing up, sometimes with served with the little paper booties on them), and boneless leg of lamb. These are tied together for practical (to keep them from cooking too fast/drying out) or decorative reasons (to keep the shape).
The reasons include both practical and decorative. In addition to the above, many cuts of meat that are usually pot-roasted are uneven in shape and thickness. You tie them so that they cook more evenly.