St Louis ribs are straighter, larger, and fattier, thus demanding a longer cooking time on low heat. Whereas baby back ribs are curvier, leaner, smaller, and need a comparatively shorter cooking time. Since baby backs are leaner, they are usually priced higher than fat-rich St Louis ribs.
As a seasoned pitmaster, being pork-rib ready is the difference between a ‘did we have to come’ and a ‘that’s one hell of a bbq’ cookout. So to help you push your grilling game a notch higher, let me tell you what to consider.
This article delves into the differences between St Louis ribs and baby back ribs to help you decide which one is better for your recipe. Shall we?
5 Distinct Differences Between St Louis and Baby Back Ribs
The differences between St Louis ribs and baby back ribs are far from subtle and largely affect the quality of the final dish. They include:

Location on the Hog
St Louis ribs, commonly referred to as St Louis spare ribs refer to a very neatly-trimmed portion of spare rib. They are cut from the rib cage area right next to the hard breastbone. During dressing, butchers remove the ribs before trimming most of the connective tissue and cartilage around it, giving St Louis-style ribs a polished look.
Baby back ribs, on the other hand, come from the higher part of the rib region closer to the loin muscle which is why they are commonly referred to as loin ribs or pork loin back ribs. They are called baby backs because they are the smallest of pork ribs.
This simple distinction between the two lays the groundwork for all their other variations like size, flavor, texture, and consequently, the cooking methods they are suited to.
Size & Appearance
St Louis ribs have a uniform rectangular shape which makes them great for competition circuits. The meat on the bone is tidy enough for presentation and even easier to eat. They are usually larger than back ribs often with a length of between 5-9″, a thickness of 1-1.5″, and a weight of 2.5-3 pounds a rack.
Baby back ribs have a distinct shape because the bones curve upwards toward the end. Baby back ribs are small often ranging between 3-6″ in length, about an inch thick, and an average weight of about 2 lbs.
As for appearance, St Louis ribs have considerably more marbling and connective tissue running through the meat. This is because it is close to the breast bone. As you know, the breast bone is a very hard bone tasked with protecting inner organs. It is rich in connective tissue which means the meat around it will be tougher.
This is a far cry from baby back ribs that are cushioned next to the soft loin that does not do much heavy lifting. Baby back ribs, therefore, offer leaner meat with less connective tissue and less fat content. They also have more meat on top of the bone than intercoastal meat(meat between the bones).
Fat Content & Flavor
As with most types of meat, fat translates to flavor. As earlier mentioned, St Louis-style ribs have a higher fat content and more connective tissue. As the fat renders, it flavors the meat giving your pork ribs an even more robust flavor. When cooked properly, St Louis ribs get fork-tender, juicy, and super flavorful.
With the bolder, more intense flavor of Louis-style ribs, it is best to go easy on the spices and instead let the fat do its magic. I suggest using a marinade rich in kosher salt if you hope to tenderize them before you cook. Pair them with a strong barbecue sauce or a spice rub to provide assertive flavors that do not overwhelm the juicy meat. I use Traeger's Texas Spicy BBQ Sauce for its fiery tangy notes.
Comparatively, baby back ribs are leaner with less fat which means less flavor. Moreover, they can easily dry out as they cook to yield chewy, bland pork ribs. That said, with a mild bbq sauce pork rub, you can prepare baby backs just as flavorful as St Louis ribs if not more. I recommend Traeger's Pork Rub which is a nice blend of sugar, paprika, and garlic.

Cooking Method & Time
Both St Louis and baby back ribs can yield soft, tender meat when grilled or smoked.
St Louis ribs have more connective tissue which requires time to break down. To bring out their flavor, the fat also needs time to render and soften the meat fibers which is why it makes sense to opt for low and slow cooking methods like the sous vide method, and cooking in the slow cooker, among others.
St Louis style ribs are however the preferred option for smoking and barbecues due to their thinner and flatter shape that makes browning them over open fire a piece of cake. To prepare St Louis-style ribs, gear up for a total cooking time of about 3 hours.
Baby back ribs have a relatively shorter cooking time so they can be fried, baked, roasted, or even stewed. They also make for fantastic grilled pork ribs but for this, I recommend using the oven to get the curved bones evenly cooked. If you opt for baby back ribs, a total cooking time of 2 hours should get the job done.
Food safety calls for ribs to be cooked to an internal temperature of 145 degrees. That said, I find pork cooked to this temp is still tough because the connective tissues have not had enough time to break down.
For more toothsome ribs, I recommend an internal temperature of 160 degrees. Some grillers go higher than this but that depends on how you like your meat.
Price
In general, leaner cuts of meat cost more than their fattier counterparts. Given that baby back ribs are leaner than St Louis ribs, they come with a higher price tag.
What Are St Louis Ribs?
See, back in the day, larger meat packers would sell spare ribs inclusive of the rib tips. This caused a lot of wastage since most people do not care for the rib tips because they are full of tough cartilage.
To curb this wastage and utilize the rib tips between 1930 and 1960 when some meatpackers came up with a new, more finished cut for pork ribs. The signature St Louis-style ribs involve trimming the sternum, the chewy cartilage, and of course, the rib tips which are then sold separately. This leaves the ribs straighter and flatter.
Because St Louis-style ribs are located near a collagen-rich breastbone, the meat on the bones is tough and rich in fat making it better suited to low and slow methods of cooking. They have more intercoastal meat and less meat on top of the bone.
In these ways, St Louis style ribs is a term that more accurately describes a cutting style as opposed to a variation of pork ribs.
What Are Baby Back Ribs?
Contrary to popular opinion, baby backs are not sourced from baby pigs. They are basically the upper ribs of a pig’s carcass located closer to the loin muscle where the rib cage meets the spine.
Baby back ribs are the smallest of the pork ribs. They come as a rib rack of 10-13 curved bones.
Baby back ribs are characteristically leaner and tender than other ribs because they are cushioned next to the loin muscle. They feature less intercostal meat and more meat on top of the bone.

FAQs
1. Which Are Better St Louis Ribs or Baby Back Ribs?
The St Louis vs baby back ribs debate largely comes down to preference because frankly, both types of ribs can make finger-licking pork dishes. To nudge you in the right direction though, here are some pointers:
Despite St Louise rib meat being the more flavorful choice, they are fatter and larger, requiring a longer cooking time. If you have some time to kill, go ahead and prep some Louis-style ribs. I’m sure you’ll love them.
Baby back ribs may not be as naturally flavorsome as Louis ribs because they have a low-fat content but they are leaner. This means fewer calories and less fat for you, making it the healthier option between the two.
Additionally, if you are crunched for time the shorter cooking duration of baby back ribs may just be the boost you need.
2. Are St Louis Ribs Chewy?
Yes, they can. If they are not cooked right, St Louis ribs, just like other types of meat can be chewy.
To Recap
To conclude, St Louise ribs and baby back ribs differ in size and appearance, fat content and flavor, cooking time and methods, and finally in price. Both can make delicious ribs but only when prepared properly.
If you are working with St Louis-style ribs, be sure to give it more time to cook to make the best of all that fatty goodness. If you prefer baby back ribs, I strongly suggest using a meat rub to enhance its flavor.
With that, I bet you feel confident enough to grace your picnic table with either of these mouth-watering finger foods.