As with most topics in barbecue, everything is an argument. This even includes things like if a pork shoulder (butt) should be placed fat cap up or down in a smoker.
The general suggestion is for the fat cap to be oriented towards the heat source. The fat cap functions as an insulator and works to protect the meat from direct heat.
With that said, pork butt is a cut of meat that naturally has tons of intramuscular fat. The orientation of the fat cap doesn't tend to matter as much, if at all. Truthfully, you can remove all of the exterior fat and still be completely fine.
Personally, I opt to remove the "false cap" - more on that below.
The pork butt comes from the shoulder area of the pig. The side of the pork butt that faces the skin is covered in a layer of subcutaneous fat - this fat is referred to as the fat cap.
A pork butt is a large piece of meat - weighing anywhere from 6-10 lbs. However, the subcutaneous fat or fat cap is sometimes trimmed before it's vacuum packaged.
Here's a picture of the fat cap side of a pork butt:
Note: The above is how the pork butt's fat cap came packaged and is untrimmed by me.
Pork shoulder or picnic shoulder is similar - it will typically have a fat cap. However, unlike pork butt, the picnic can come with the pig skin on. If you're goal is to make pulled pork with crackling, you'd want to make pulled pork with a picnic shoulder.
There are a few other differences between pork butt and picnic - learn more in this article.
There are three main opinions when it comes to the orientation of pork butt on a smoker:
After testing all the above over the years - in my opinion - it doesn't really matter how you put the pork butt on the smoker.
With that said: If you are a person who leaves the fat cap on, I'd suggest orienting the fat cap towards the heat source.
Depending on your smoker and its setup, the fat cap can function as a barrier between the effects of the drying heat - which keeps the meat moist.
Granted, depending on your smoker, fat drippings can also spike pit temperature too.
As you can tell, there are arguments on both ends of the spectrum.
Either way, pork butt naturally contains tons of intramuscular fat. It's to the point that the orientation of the meat inside the smoker doesn't really matter; It could be up, down, sideways, flipped, etc. and it wouldn't matter.
For me, the goal when smoking pork butt is to maximize tenderness and edible bark. Aside from stalling, pork butt has no trouble getting to tenderness for pulling and won't be "dry" because it has so much intramuscular fat.
You're also not "presenting" the meat like you would a brisket, you're pulling it.
Meaning, all of the lean meat, fat, and bark is being mixed together. Where-as a brisket is served as slices and having a thin band of rendered fat on the top of the meat adds to the eating experience.
Due to the above factors, I opt to completely remove the false cap.
Upon looking closer at the fat cap you'll start to notice that there are three layers:
Here's what I mean:
Here's me removing this cap:
Here's a visual of the false cap after being removed and the layers:
The exterior hard fat and the thin layer of meat below it are what people call the "false cap."
Here's the pork butt next to the false cap after being removed:
Honestly, you could get even more aggressive than I did and continue removing exterior fat and you'd still turn out a tender product. It's just a matter of how lazy you're feeling that day.
Exterior hard fat doesn't tend to render well nor is it palatable. I'd also wager to say people like edible bark more than they like fat.
This is the same reason when you trim brisket, you leave 1/4-1/2 inch on the meat. Leaving more will result in people trimming these huge globules of fat off - which is essentially a waste.
Dry rubs also won't penetrate fat - meaning your meat also isn't benefiting from the rub; While most rubs barely penetrate meat (a millimeter or two) they do help to form "crust" or bark.
Meaning, the false cap doesn't benefit your eating experience.
People who leave the fat cap on will do things like:
In my opinion, if you have the 3-5 minutes or so, I'd suggest removing the false cap. If not, you can use your hands to remove this fat before mixing the pull together.
Lots of people who smoke pork butt are apt to be as lazy as possible (like Me!). This is mainly because pork butt is super forgiving; It's truly the easiest cut of meat to smoke in barbecue.
If you're in the camp of leaving the fat cap on your pork butt, I'd suggest orienting the fat cap towards the heat source.
The goal here is to render the exterior fat as much as possible. You can also use the fat as a heat buffer between the meat surface and the drying heat of the smoker.
If I'm being super lazy, I'll leave the false cap on and smoke the pork butt on my Pit Barrel Cooker (PBC) with the fat cap facing the fire. The PBC cooks hot and fast at around 300-325F.
Here's a visual:
Typically what will happen is the false cap will borderline become charred/inedible but it will quite literally peal off the bottom of the butt.
I discard this piece of false cap and you're left with rendered fat from the true fat cap to mix into your pork butt to add succulence.
To reiterate, this also removes a significant portion of your bark.
If you're someone who doesn't believe in removing the false cap, I'd suggest orienting the fat cap towards the heat source.
Below is a table/cheat sheet to use for reference; It lists common smokers and if the fat cap of your pork butt should be up or down.
|Type of Smoker||Fat Cap Up, Down, or Flipped|
|Offset smoker (standard and reverse flow)||Up|
|Weber Smokey Mountain (WSM) as well as most water smokers||Down|
|Ugly Drum Smokers||Down|
Note: This table isn't all encompassing. I did my best to list the most common smokers/cookers that are used.
If you're interested in seeing how heat moves in these various smokers - be sure to read my article here.