The pork shoulder (picnic) and pork butt (Boston butt) are cuts of meat that are commonly mistaken for each other; It also doesn't help that the names for these cuts of meat are quite misleading.
With that said, they come from two different places on the pig; They also taste a bit different from one another.
The most basic differences between pork butt and pork shoulder is that pork butt comes from the higher foreleg of the pig and pork shoulder is further down. Pork shoulder has a higher muscle-to-fat ratio as it's a heavily exercised muscle where-as pork butt has a lot more intramuscular fat.
Most folks would think that since this cut is called pork "butt" that it's sourced from the hindquarters, however, it actually comes from the front of the pig.
Pork butt or more colloquially referred to as Boston butt, is a cut of meat sourced from the pig's shoulder blade, behind the neck/head.
A typical bone-in pork butt weighs 6-10 lbs.
The name "Boston Butt" stems from Colonial New England before refrigerators were invented. The Butchers would pack inexpensive cuts of meat like the shoulder into large barrels called "butts" or casks for transportation.
The name stuck and now we're left with the Boston Butt.
The pork butt consists of several different muscles (roughly 12) that converge at the shoulder. These muscles are then attached to the shoulder blade via connective tissue.
It's for this reason that a bone-in pork butt looks like a small boulder and a boneless pork butt looks like a relaxed muscle.
Note: Pork Butt is sold both boneless and bone-in. When sold boneless, the butt is sold as two half portions.
The muscles that comprise the pork butt aren't heavily exercised and as a result, it's less tough and sinewy. Rather, it's quite marbled with intramuscular fat which works wonderfully for low and slow barbecue.
As the temperature climbs, the meat sweats which results in moisture loss.
This sweating also causes the meat to stall - this is commonly combated through wrapping with aluminum foil.
However, this moisture loss is made up for through the rendering of fat into gelatin.
In almost all instances, I'd rather use the pork butt than the picnic shoulder.
The pork butt has way more marbling and intramuscular fat. This fact alone makes it one of the best meats to smoke for a beginner as it's resistant to overcooking; Granted, most folks are pulling it anyway.
The only real time where you'd want the Picnic over the shoulder is if the Grocery Store doesn't have any Boston butt's or if you're after a dish that requires pig skin or the skin still intact - as the pork butt is sold skinless.
The picnic also lacks the prized Money Muscle. Which is by far the best muscle on the entire pig to eat.
The pork butt and picnic are essentially the same price. You'll likely find them both priced similarly at around $0.99 - $1.99/lb. The picnic is usually cheaper than the pork butt simply due to popularity.
Common dishes using Pork Butt:
A whole pork shoulder weighs 12-18 pounds and is separated into two portions, an upper and a lower.
The upper portion is the pork butt (above) and the lower portion is the picnic, which most folks call the shoulder.
Pork picnic or pork shoulder comes from just below the Boston butt. It includes all of the leg (or arm) until the hock - which is just above the pig's front foot.
A whole pork picnic weighs 6-9 lbs.
It's not uncommon for the picnic to be cut into two portions, an upper and lower. The upper arm is meatier and sold skinless. The lower foreleg contains more bone and is sold skin-on.
When de-boned, you might see this cut of meat called "pork cushion."
Unlike the pork butt, the picnic is heavily exercised by the pig, meaning it's a tough muscle with lots of connective tissue.
For some reason a lot of websites will say it "lacks fat" which isn't true. The main reasons folks prefer pork butt is simply because it offers more meat yield and it has more fat.
The name "picnic" ham stems from its use. It's more so for casual dining (like having a picnic) rather than formal dining (like Easter or Christmas) where most folks would use a ham from the hindquarters.
The picnic is usually the most inexpensive cut in the meat case - even when beside a pork butt.
The biggest reason someone would want to use the Picnic rather than the pork butt is because the Picnic is almost always sold bone-in with the skin on.
Even in my photo above, the pork picnic has some skin on and has the bone-in.
With that said, you can pretty much use the pork shoulder for almost all of the same dishes as the pork butt.
In my opinion, picnic tastes similarly to ham - hence being called a "picnic ham." For this reason, it makes for wonderful sandwich meat.
Common dishes using the Picnic Shoulder:
Aside from general anatomical location on the pig, there aren't major differences between the cuts.
If your goal is to simply smoke pulled pork and you want to know if the picnic can substitute for the pork butt - it absolutely can, only your meat yield will be a bit lower due to bone and skin removal.
This is important to keep in mind if you're trying to determine the amount of pulled pork for an event and need to know how much raw pork to buy.
Here's a quick overview of the pork butt and pork shoulder for comparison:
|Pork Butt||Pork Shoulder|
|Contains more intramuscular fat or marbling||Contains more lean meat and is quite tough (it still does contain fat though)|
|Sold bone-in and boneless without skin||Sold bone-in with and without skin. When sold boneless, it's called pork cushion.|
|More meat yield per pound||Less meat yield per pound|
|Typically slow smoked for pulled pork||Typically slow roasted or grilled (can also be slow smoked)|
|Square shaped||Triangular shaped|