Thu Jun 2, 2011
By far, my favorite cut of ribs are a St. Louis style. This rectangular rack trimmed from a full rack of spare ribs provides the great flavor of spare ribs with the uniformity and manageable size that you get from baby backs. When first starting to learn how to barbecue, I'd go to Whole Foods to pick up racks already trimmed to a St. Louis cut, but I was paying a premium to have the work done for me, so I quickly learned how to butcher these at home, which is quite easy once you learn how.
I'll take spare ribs over baby backs any day. Baby backs, or more correctly, loin back ribs, are the cut closest to the back bone of the hog, and I'm guessing with less fat and connective tissue, they quickly became the more desirable—and more expensive—cut. Spare ribs, on the other hand, are a beast with a lot of fat and cartilage, making them more difficult to cook, but when done low-and-slow in a smoker, they turn into a tender, meaty slab that blows the baby back out of the water in my opinion. The problem is that all that cartilage and fat also creates ribs that are disproportionate sizes and can be difficult to eat; the St. Louis cut is the solution to this.
Trimming to a St. Louis style really only involves 2 main cuts. To start, feel for the first bone on the small end of the ribs, then make a cut just to the side of that bone to trim off the end flap of meat. Next, feel along the top of the rack for where the tops of the bones end and the cartilage takes over. Once you have a feel for where that is, cut along that line to separate the cartilage portion of the rack from the actual ribs. You should now be left with a pretty perfectly rectangular rack, which is the St. Louis cut. You should save those trimmed pieces and throw them in the smoker with the ribs—they'll be done before the ribs are and provide a nice little snack during the cook.
From here, to finish trimming the ribs, flip the rack over. There is usually a flap of meat running diagonal across the back of the ribs. Trim this piece off. If it's big enough, this can also be saved to go into the smoker, otherwise, I usually toss this small scrap.
Next step is to remove the membrane on the back of the ribs, which can sometimes be a bit tricky. The start it off, use a knife or fingernail to pry up a corner of the thin membrane from the edge of the ribs. Grab that starting point you created with a paper towel and slowly start to pull it upwards. Once a good piece of the membrane is free, you should be able to to pull the rest off in one quick motion. Although this works most of the times, I still get hung up here on some racks where the membrane is stubborn and comes off in pieces. It just takes some time, practice, and patience to get this step down and completed.
Now that the ribs are cut and peeled, cut off any hard or excess fat from both sides of the rack. Even though fat is a good thing to have when cooking low-and-slow, too much of it here and it won't completely render in the 5-6 hours it'll take the ribs to cook and you'll be left with overly fatty ribs, which are usually not very pleasant.
Now the ribs are fully prepped and ready to be rubbed, smoked, and eaten. The whole process of cutting down a rack to a St. Louis style is pretty fast once you have the hang of it and creates the most flavorful, meaty, and uniform rack for churning out really stellar barbecue.