Costco’s St. Louis-style ribs are pork ribs, not beef ribs. Pork ribs are cut from the spare ribs or loin back ribs of a pig. Beef ribs, on the other hand, come from the rib section of a cow.
What cut of pork are St. Louis ribs?
St. Louis-style ribs are spare ribs that have been trimmed of the rib tip bone, cartilage, and excess fat. This leaves a rectangular-shaped rack of ribs containing mostly meat. The term “St. Louis” refers to the cut and shape, not where the ribs came from.
There are two main types of pork ribs:
- Spare ribs – Taken from the belly side of the pig
- Baby back ribs – Taken from the back/loin area close to the spine
St. Louis-style ribs are cut from spare ribs. The brisket bone and sternum cartilage are removed to make them rectangular. This is different from baby back ribs which are naturally more curved in shape.
What do Costco’s St. Louis ribs look like?
Costco’s Kirkland Signature Pork Spareribs are already trimmed into the St. Louis style. They come pre-cut into a rack with the brisket bone and rib tips removed. The rack contains 10-12 meaty ribs with a straight cut on both ends.
Costco ribs are also membrane-removed, meaning the tough membrane on the back of the rack has been peeled off for easier eating. Overall, they have an attractive presentation with a good ratio of meat, fat, and bone.
How do pork and beef ribs differ?
There are a few ways to tell pork and beef ribs apart:
| Pork Ribs | Beef Ribs |
|---|---|
| Come from the belly or loin area of a pig | Come from the rib section of a cow |
| Have more tender meat | Have more fat marbling and richer flavor |
| Are long and narrow in shape | Are wider and meatier |
| Have a curved shape unless cut St. Louis-style | Naturally have a straight shape |
How should you cook Costco pork ribs?
Costco ribs can be cooked many ways, but low and slow barbecuing is recommended to fully tenderize the meat and render the fat. Try cooking them indirectly over low heat (225-250°F) for 4-6 hours, flipping and basting with barbecue sauce occasionally. Use a digital meat thermometer to ensure they reach 195-205°F internally before taking them off the grill.
You can also braise or bake the ribs at 300°F for 2-3 hours until fall-off-the-bone tender. For convenience, the ribs can be boiled or pressure cooked first to reduce cook time.
ideal barbecue tips
- Remove the membrane first for better smoke absorption
- Season the ribs generously with a rub or sauce
- Use indirect heat, placing ribs away from direct flame
- Spritz with apple juice or other liquid during cooking
- Wrap ribs in foil if struggling to get tender
- Allow ribs to rest 5-10 minutes before serving
Conclusion
In summary, Costco’s popular St. Louis-style ribs are made from pork spare ribs, not beef ribs. The ribs are already trimmed into the recognizable straight rectangular rack shape. While pork and beef ribs have their differences, Costco’s pork ribs can be cooked low and slow to achieve finger-licking, fall-off-the-bone results. Follow the tips above for your best backyard barbecue ribs using Costco’s product.