Full and St. Louis Ribs
Regular spareribs are cut close to the belly of the pig (which is also where bacon comes from ). Because whole spareribs contain the brisket bone and surrounding meat, each rack can weigh upward of 5 pounds. Some racks of spareribs are so big they barely fit on the grill.
For a more manageable cut, we look 250 miles east of Kansas City. With "St. Louis" ribs, the brisket bone and surrounding meat are trimmed off to produce a narrower, rectangular rack that usually weighs in at a relatively svelte 3 pounds. In our opinion, St. Louis ribs offer all the taste of whole spareribs without any of the trouble. If you can find only whole spareribs, use the biggest grill possible and be prepared to increase the cooking time significantly.
Baby Back Ribs
Baby back ribs (also referred to as loin back ribs) are cut from the section of the rib cage closest to the backbone. Loin center-cut roasts and chops come from the same part of the pig, which explains why baby back ribs can be expensive. This location also explains why baby back ribs are much leaner than spareribs—and why they need special attention to keep from drying out on the grill.