The Difference Between Baby Back Ribs and Spare Ribs

baby back vs spare ribs

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Do you struggle to tell the difference between baby back ribs and spare ribs? 

While the style of cooking is often the same, there are a few key differences that will affect how you cook these two types of ribs.

What is the Difference Between Baby Back Ribs and Spare Ribs?

They may sound very similar, but these two popular cuts differ in several ways. 

diagram with cuts of pork ribs

Spare ribs are larger, meatier, and contain more bone and fat than baby back ribs. Many people also consider spare ribs to be the most flavorsome. 

Baby back ribs, on the other hand, are smaller, more curved, and the leanest and most tender of ribs. 

Baby Back Ribs

Also known as back ribs, loin (back) ribs, or just simply baby backs, baby back ribs come from the upper rib cage. They are connected to the backbone, just under the loin muscle, and situated directly above the spare ribs. 

Being shorter than spare ribs, from where they get their name “baby”, they are pretty easy to identify. 

Raw baby back ribs on a parchment paper

Your average slab of baby back ribs usually weighs around two pounds and contains 11-13 bones. The slab will taper off at one end, with a more pronounced curvature where it meets the spine. 

More tender and much leaner than spareribs, baby back ribs weigh less and thus cook faster. 

Thanks to their increased popularity in recent years, you may find that your slab of baby back ribs comes with a small amount of loin meat attached on top. Traditionally, loin meat was more expensive, but now baby back ribs are in demand, butchers tend to leave more loin meat on the ribs than previously. 

With each rib measuring anywhere between three to six inches long, one heavy slab should be enough for two adults or one very hungry adult. 

However, as baby back ribs are smaller and cost more than spare ribs, you may wish to save them for smaller gatherings and opt for spareribs when feeding a crowd. 

Spare Ribs

Also known as spares or side ribs, spare ribs are cut from the section of the rib cage below the baby back ribs. 

Take a look at your slab of spare ribs and you’ll be able to see where it was cut from the baby backs – the edge with visible bones and marrow showing. 

Raw pork spare ribs on a white background

The other edge of your spares comes from the chest, complete with small gristle (known as the rib tips), cartilage, and small bones.

According to USDA requirements, a spare rib slab needs to have a minimum of 11 bones. They have less meat on top of them than baby backs, with extra meat between the bones and what is known as flap meat. This meaty flap was once part of the animal’s diaphragm. 

Larger and flatter than baby backs, spare ribs tend to weigh in at an average of around three pounds per slab. The meat has more fat marbled through it, with the extra bones and connective tissue combined resulting in more flavorsome, richer tasting meat.

While your rack of spares weighs more than your average rack of babies, they do have quite a bit more bone and cartilage. This makes them cheaper than baby backs, as does baby back’s sudden soar in popularity. 

A slab of spare ribs should be plenty for two – while it may look like a lot, bear in mind that half or a little more is bone. 

What about St. Louis ribs?

Now you know the difference between spare ribs and baby backs – what about St. Louis cut ribs? 

Often abbreviated to SLC, or known as a Kansas City or BBQ cut, St. Louis cut ribs are simply trimmed spare ribs

Cooked St. Louis style pork ribs on a wooden board

You may also hear them, incorrectly, called SLC spare ribs. However, as St. Louis ribs have the gristly rib tips removed, alongside part of the meat flap, they are technically no longer spare ribs. 

Removing the tips and flap gives you a nice, even rectangular, flat slab. This makes SLC ribs a popular choice for competition barbecue where presentation maters.

It’s pretty simple to cut spare ribs into a St. Louis cut yourself. This way, you will also get to cook the tips and flap as well. The resulting SLC slab is much more uniform, making it easier to cook and much easier to eat – there’s less cartilage and an even, regular shape. 

Note, that due to the popularity and increased price of baby back ribs, some butchers look to cash in on this by branding St. Louis cut ribs as baby spare ribs. Baby spare ribs are simply another name for a St. Louis cut, as they are just a shorter version of spare ribs. 

So buyer beware, if you are looking for baby back ribs, don’t fall into this trap!

What to look for when buying ribs?

Whether you’re shopping for a slab of baby back ribs or spare ribs, make sure you apply the following tips: 

  • Good meat coverage – you don’t want a rack with overly exposed bones, known as a “shiner”. Not only will you end up with less tasty meat to enjoy, the bones may fall out during cooking. 
  • Look for visible fat throughout the rack – even marbling ensures even flavor and distribution of meat. Large fat deposits will break down, leaving you with a gap and a meatless rib. 
  • Even thickness – for better, more consistent cooking throughout.
  • Pink-red in color – reject discolored slabs or ones with dried out edges.

Can you substitute between each type of rib?

Yes, it is usually possible to substitute one type of rib for another. 

So, if you have a recipe that calls for spare ribs and you could only get baby backs, or vice versa – don’t worry. 

Just keep in mind that you’ll need to alter your cooking duration and in some cases your cooking style or temperature. 

Here’s what you need to bear in mind when substituting one type of rib for another:

  • Spare ribs are larger, with more bone, and will take longer to cook than baby back ribs, so be sure to add on extra time.
  • Baby backs, being smaller than SLC ribs and spare ribs, will cook faster. They also have less bone and fat to prevent them from drying out.
  • Spare ribs are best cooked low and slow, whereas baby back ribs will need to be regularly checked to ensure they are not overcooking and becoming dry.
  • SLC ribs, thanks to their straighter, more regular form, are a better choice for browning in a pan on your stovetop.
  • Consider baby backs or cutting your spares into an SLC for easier-to-eat ribs.
  • If you’re looking for a strong meaty flavor, but your store is out of spare ribs, then you may wish to spice up your less flavorsome baby backs with a variety of rubs

Wrapping it up 

So, there you have it! Both baby back and spare ribs are delicious choices, but there are a few key differences to keep in mind. 

Baby backs come from the back loin section and are smaller and more tender. 

Spare ribs, or side ribs, come from under the babies and are larger, tastier, and meatier, with a lot of bone and more fat. 

Looking for a tender, lean rack of ribs and don’t mind paying out a bit more? Go for baby backs. For a larger rack with more flavor, but more bone and fat, go for spare ribs. 

What do you think? Do you have a favorite? Be sure to drop us a comment below – we’d love to hear from you!

Joe Clements

Joe Clements

As the son of a vegeterian, I grew up dreaming about meat. Now as the founder and editor in chief of Smoked Barbecue Source I get to grill, barbecue and write about meat for a living! I'm sharing everything I learn along the way on my journey from amateur to pitmaster.
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