BABY BACK RIBS are taken from around the loin. They are shorter than spare ribs or St. Louis style ribs, and have tons of lean meat between and on top of the bones. Unfortunately, they are also typically more expensive than the other types of ribs.
SPARE RIBS come from the belly of the pig, after the bacon and pancetta has been removed. They contain more meat between the bones, but less on top. They are perfect for this low and slow cooking method we’re going for, due to the excess fat in this area.
ST. LOUIS STYLE RIBS are really just spare ribs with a little more work done to them. When a butcher removes the sternum and the connecting cartilage, what is left is a St. Louis Style rib. These are a favorite because they are a bit easier to work with, without sacrificing any flavor.