Spare ribs are the classic barbecued ribs. They are the bones left over (spare) when a pork belly is trimmed for making bacon. They consist of the lower portion of the rib bone along with the cartilage that joins the ribs to the breastbone. I think the taste and texture of these "belly ribs" is much better than baby back ribs. They come in slab form or a rack, trimmed down to St. Louis cut. Serious pit bosses will select spare ribs that are “three and under” meaning that the rack weighs 3 pounds or less, but don't worry if you can't find them in smaller sizes. Given time, they will cook themselves tender.
Here is how to trim the slab:
First, the ribs need to be trimmed and prepared. Turn the slab rib side up and slice off the skirt meat, flush with the bones. (the skirt is the lean muscle that covers the breastbone and cartilage)
Next, remove the membrane. Start in one corner, work an edge loose then use a paper towel to grip it, and peel it off. If it is really stubborn, coil the ribs with the meat side to the inside of the coil. This will stretch the membrane and make it release easier.
Using a sharp knife and starting at the wide end of the slab, cut just above the ends of the bones down the length of the slab, cutting through the cartilage. (You can cut off one or two of the ribs on the small end if you wish). Trim off any large areas of fat. Fat deposits, like the ones seen on the 5th & 6th ribs from the left should be scraped off with a teaspoon or the back of a knife. Many refer to this method as a KC trim. A St. Louis cut still has the skirt meat intact.
Save the strip or “rib tips” and the skirt to cook along with the ribs. They are good snacks or can be chopped later for beans etc.
Here is a picture showing the trimmed ribs, the skirt and the strip (cut into pieces) and the amount of fat trimmed off. Note the triangle shaped area of fat that was trimmed off of the wide end of the rack.
