St Louis Ribs vs Baby Back vs Spare Ribs

First of all, in the butchery world, spare ribs can be a slightly confusing term. Traditionally, it can be used quite generally to describe ribs, but these days most customers use “spare ribs” to mean the larger ribs from the belly side of the pig.

So, when people ask us for spare ribs, what they are usually looking for are belly ribs. St Louis ribs are made from those same belly ribs, but trimmed into a neater, more even rack.

In simple terms, the three main names you will see are baby back ribs, spare ribs and St Louis ribs. They are all pork ribs, but they come from different parts of the rib section, cook slightly differently, and suit slightly different jobs.

Baby back ribs

Baby back ribs are cut from the loin side of the pig. More accurately, they sit just below the loin muscle, where the ribs meet the spine. This is why baby back ribs are usually slightly curved.

A rack of baby back ribs is usually shorter and neater than a rack of spare ribs. They are often around 10cm wide and usually have around 12 to 13 rib bones. A rack of baby back ribs tends to look more even from end to end, almost like a strip of ribs.

Baby back ribs usually have thicker bones than belly ribs, but they are also generally meatier, leaner and more tender. One nicely butchered and trimmed rack will often weigh around 500g, which is usually enough for one hungry adult.

If you want a deeper explanation of this cut, read our guide to what baby back ribs are.

Spare ribs

Spare ribs, as most people use the term now, are cut from the belly side of the pig. You may also hear them called belly ribs.

These ribs continue on from the baby back ribs and run down through the belly towards the sternum. This area can include the rib tips, which contain more bone and cartilage. Rib tips are often trimmed off, especially when making St Louis style ribs.

A rack of spare ribs is usually larger, flatter and wider than a rack of baby back ribs. It often tapers into more of a triangle shape rather than staying the same width all the way along.

Spare ribs have longer, thinner bones and usually a bit more fat. They are not always as naturally tender as baby back ribs, but when cooked properly, they can be absolutely delicious. They are especially good for low and slow cooking, smoking and BBQ.

St Louis ribs

St Louis ribs are not a completely different part of the pig. They are made from spare ribs.

The difference is in the trimming. To make St Louis ribs, the rib tips and uneven sections are trimmed away, leaving a squarer, flatter and more even rack. This makes them easier to cook evenly and easier to portion.

That neat shape is one of the reasons St Louis ribs are so popular with BBQ cooks. They look good, cook well, and have plenty of flavour from the belly side of the pig.

So if you are wondering where St Louis ribs fit in, think of them as a trimmed, tidied-up version of spare ribs.

St Louis ribs vs baby back vs spare ribs: what is the difference?

The main difference is where they come from and how they are trimmed.

Baby back ribs come from the loin side of the rib section. They are shorter, leaner, curved and usually more tender.

Spare ribs come from the belly side. They are larger, flatter, fattier and need a little more cooking, but they can have brilliant flavour.

St Louis ribs are spare ribs that have been trimmed into a neater rack, with the rib tips removed. They still come from the belly side, but they are more uniform in shape.

Which ribs are best?

If you are new to cooking ribs, baby back ribs are probably the easiest place to start. They are smaller, leaner and a little more forgiving.

If you want bigger, richer, BBQ-style ribs, spare ribs or St Louis ribs are a great choice. They need a little more patience, but the flavour is excellent when cooked low and slow.

If you are set on making proper St Louis style ribs, then you need spare ribs that have been trimmed into that classic St Louis shape. It is basically the law.

How do you cook pork ribs?

Whichever ribs you choose, the best results usually come from cooking them gently rather than rushing them.

Baby back ribs can be cooked in the oven, on the BBQ or in a smoker. Spare ribs and St Louis ribs usually benefit from a longer, slower cook because they contain a little more fat and connective tissue.

If you are cooking ribs in the oven, read our guide to how to cook baby back ribs in the oven. If you are short on time, you may also like our guide on how to cook ribs in the oven fast.

FAQs about St Louis ribs, baby back ribs and spare ribs

Are St Louis ribs the same as spare ribs?

St Louis ribs are made from spare ribs, but they are trimmed differently. The rib tips and uneven sections are removed, leaving a neater, flatter rack.

Are baby back ribs better than spare ribs?

Baby back ribs are usually leaner, smaller and more tender. Spare ribs are larger, fattier and often richer in flavour. Which is better depends on what you want to cook and how you like your ribs.

What is the difference between baby back ribs and St Louis ribs?

Baby back ribs come from the loin side of the pig and are shorter and more curved. St Louis ribs come from the belly side and are trimmed from spare ribs into a flatter, squarer rack.

Why are they called baby back ribs?

Baby back ribs are not from baby pigs. The name refers to the fact they are shorter and smaller than spare ribs, and they come from the back or loin side of the rib section.

Which ribs are best for BBQ?

Baby back ribs, spare ribs and St Louis ribs can all be good for BBQ. Baby back ribs are easier and quicker, while spare ribs and St Louis ribs are excellent for low and slow BBQ cooking.