Fat side up or down when smoking pork shoulder

Some people say that you should pork fat side up, while others argue that fat side down is the way to go. So, which is the right way?

If you’re a meat-smoking enthusiast, or just love the taste, then you know that there’s always debate about the best way to smoke pork shoulder or pork butt (aka Boston butt). Some people say that you should cook it fat side up, while others argue that fat side down is the way to go. So, which is the right way? Let’s take a closer look at both methods to see which one produces the best results.

There was a time when I fell into the “fat side up” crowd, but then did a bunch of research and ran some tests of my own. I learned a good bit from the experts and from my own tests

Cooking pork fat side up for fat side down is a hotly debated topic. In the end, it comes down to a couple of things.

If you are looking for the best pork shoulder or the bests smoked pulled pork, read on my friend

Fat Side Up

The case for cooking pork fat side up is that the fat will render as the meat cooks, basting the pork and keeping it moist.

Additionally, many believe that cooking the pork in this orientation allows the juices to flow down into the leaner portions of the meat, producing a more flavorful final product.

Proponents of fat side-up will say it prevents the formation of a crust on the underside of the pork (but I kinda like that crust!)

Fat Side Down

On the other side of the debate are those who believe that cooking pork fat side down is the way to go.

The argument here is that by placing the fat side down, you create a barrier between the heat source and the meat, preventing it from drying out.

This makes sense to me as the idea is to cook the meat via indirect heat, which is what your smoker should be full of! If the pork is too close to the source of the heat (big pork shoulder, small smoker, etc.) then having the fat side down, closer to that source of the heat, will protect the meat.

The biggest advantage of cooking fat side down is that your rub won’t be washed away by the dissolving fat if the fat were on top. To me, this is the deciding factor.

Smoke Science time

To really understand what’s going on, we have to understand the different types of fat you’ll see on your pork shoulder and how those fats interact with the lean muscle you’ll eventually be eating.

If you want to get the most out of cooking pork shoulder or pork butt, it’s important to understand how all those delicious fats work together.

The fat cap is what you see sitting on top and then there are thick slabs between lean muscles (intermuscular). But if melt-in-your-mouth results are your goal, focus on intramuscular fat – thin lines within the muscle itself.

All three have their place in creating a succulent dish but that last one packs an extra juicy punch!

A closer look at how subcutaneous fat, or fat cap, affects the meat you are smoking.

Fat side up or down when smoking pork shoulder_subcutaneous fat cap_800
Subcutaneous fat, or the “Fat cap” does not render and will not melt into the meat.

There is a science to consider when wondering about why that fat cap doesn’t “melt” into the meat or muscle of the pork.

While there’s more to it than meets the eye, why the pork fat cap doesn’t melt into its lean muscle is based on simple science.

In simplest terms, consider how oil and water don’t mix. We learned that way back in grade school and see it every day in some form or fashion

While the meat is cooking, it is continually evaporating water in very small amounts from its surface.

Water coming out means the fat can’t go in.

It can’t swim upstream.

How intermuscular fat affects the meat you are smoking

Fat side up or down when smoking pork shoulder_intermuscular fat_800
Intermuscular fat will not fully render but some will be absorbed into the meat, enhancing the flavor.

The thick layers of fat between the lean muscle of the pork shoulder will break down and render during smoking time. However, there are silver linings around these little fat packs as well that will prevent the fatty oils from being absorbed into the meat. It happens but in smaller amounts.

This “intermuscular” fat won’t add much flavor to the meat but does contribute to its overall texture.

Personally, I love this part of the pork!

How does intramuscular far, or marbling affect the meat you are smoking?

Fat side up or down when smoking pork shoulder_intramuscular fat_800
Intramuscular fully renders, adds great texture, and tastes wonderful!

The intermuscular fat is what is often called marbling and is the target of the long pork smoking time.

We want those little strands to completely break down and render while smoking. We smoke pork shoulder “low and slow” to give these little guys ample time to fully render. Cooking at 225 degrees(F) may be as high as 250 degrees(F) for long enough until the pork itself hits an internal temperature of at least 145 degrees (F) and maybe as high as 160 degrees (F). Unless you are an expert, you should use a meat thermometer to ensure you don’t overcook. We have a couple of articles that can help, one outlines my efforts at cooking brisket without a meat thermometer (fail!), and another shows you how to probe your brisket with a meat thermometer.

This is where much of the taste and texture comes from with a well-prepared and smoked pork shoulder or pork butt.

To better understand how fats affect the taste of your meat, spend some time with “The Role of Fat in the Palatability of Beef, Pork, and Lamb“.

So what’s the right answer?

My stance is that cooking pork shoulder fat side down is the way to go. Here are my not-so-humble thoughts:

  • The theory that having the fat on top of the pork shoulder will allow the rendered and melted fat to baste and flavor the pork doesn’t hold up to science. That fatty oil cannot penetrate if water is evaporating (and water is evaporating!)
  • Having the fat between the source of the heat and the meat, even with indirect heat, prevents the meat from drying out. Smoking pork shoulder or pork butt is a long process so having that layer of fat acts as a heat shield and helps prevent the meat from drying out as much.
  • An important point here is that if your heat source is above the meat, this all turns around (literally). Aaron Franklin, smoking guru, cooks with top heat and so cooks his meat, more brisket than anything, fat side up. This flies in the face of traditional wisdom, and I wonder how the dry rub on the bottom of the meat keeps it from getting washed off, but hey, it’s Aaron Franklin.
  • If cooking your pork fat side down, the rendered fat will not wash over the pork during cooking, so your rubs will stay in place for the duration of the cook.
  • If cooking fat side up, where do you add your rubs and spices? The spices you add will penetrate, at most, about a quarter of an inch during cooking, so adding spices or rubs to the fat cap makes no sense. So you are left with adding rubs and spices to the sides and bottom, which stand a good chance of being washed off by the melting fat during the smoking process.
  • Trimming the fat to about a quarter inch and smoking it fat side down creates a delicious crust, or bark, that most pork lovers…love.

Cooking pork fat side up or down – conclusion

Well, I hope we helped a bit with the question, “fat side up or down when smoking pork shoulder?”.

My preference, and what you’ll see most other experts doing, is cooking their pork shoulder (or pork butt) fat side down for the reasons stated above.

Also, remember the side dishes. The meat takes center stage, but side dishes complete everything. It also gives your relatives something to do before they come over.

Now go enjoy the tasty smoked pork sandwich! 

Happy smoking!

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