First of all, in the butchery world, spare ribs is actually a term used to refer to ribs in general, all ribs are spare ribs, whether they come from the loin or the belly. I guess due to the rise in popularity of baby back ribs, spare ribs has become a term used for 'the other' ribs, which now means that, almost every time a customer asks us for spare ribs, what they're actually looking for are belly ribs. So, to clarify, there are 2 types of pork ribs; baby back ribs and belly ribs, which are often called spare ribs, although, they're belly ribs. Are you with me?
Baby Back Ribs
As outlined in our article What Are Baby Back Ribs?, baby back ribs are cut from the loin of the animal. More accurately, they are situated just below the loin muscle, right at the part of the ribs that joins onto the spine, which is also why they are slightly curved. They are usually cut short, around 10cm wide, and are around 12-13 ribs in length. A rack of baby back ribs will resemble a strip of ribs as they are the same width all the way along. Baby back ribs have thicker bones, when compared to belly ribs, but they are also much meatier, lender and are more tender. One nicely butchered and trimmed rack will weight around 500g, just enough to feed one hungry adult.
Belly Ribs (aka spare ribs)
Belly ribs, aka spare ribs, are cut from the ends of the baby back ribs and run round through the belly of the animal towards the sternum, which is where you'll find the ribs tips. The ribs tips contain lots of bone and gristle and are usually trimmed off, especially when making St. Louis ribs. Having said that, when they're cooked right, rib tips are pretty delicious, you may even find them of the menu of your local smoke house. Anyway, belly ribs are cut much longer than back ribs, and are around 12-13 ribs in length. A rack of belly ribs will be much wider at one end than the other, they taper down in a kind of triangle shape. Belly ribs have long thin bones, and, as they aren't as tender, and contain a bit more fat, need to be cooked with a bit more care. It has to be said that belly ribs can be absolutely delicious when cooked properly. St. Louis ribs are always made using belly ribs (with the rib tips removed), and are so good that they usually have their own class entry in BBQ competitions. A rack of belly ribs will usually be around 1.00KG in weight, but can be easily be over 1.50KG, especially if the ribs tips are left on. A rack of belly ribs will usually feed 2 hungry adults.
So, back ribs or belly ribs, what's the difference? A rack of back ribs resembles a strip, they are cut shorter than belly ribs, are leaner, and more tender, but they're going to cost you more than belly ribs. A rack of belly ribs looks more like a triangle, and, as they're not as tender, and contain a bit more fat, are going to take a bit more cooking. On the upside, you aren't going to pay as much for them.
Really, in terms of taste, there's not going to be much difference, but if you haven't got much experience of cooking ribs, I'd suggest you start off with back ribs, they're just going to be easier to get right. On the other hand, if you're set on making some delicious St. Louis style ribs, then you have no choice, you have to use belly ribs. It's basically the law.