Darn you, lean pork!
I purchased a 4lb pork shoulder from one of my usual sources and it seemed reasonably well marbled with a tidy little fat cap. This morning, I gave it a good rub with S&P, oregano, and thyme, then set it gently into my oven at 225-235 (my oven fluctuates a bit this low).
I started peeking in at about 4 hours, but let it keep cooking until my tongs could pull some nice loose pieces off with a minimum of pressure (about 7 hours).
Sounds good, right?
Now that it's rested about an hour, i went to sneak a pinch to gnaw on while I contemplate the rest of dinner, and the pinch 1 inch from my tong test is DRY, HARD, and dare I say It, BURNT! Boo to lean pork! Bring back my fat!
Boy, it's a harsh, cold world if we're gonna have to start larding our pork shoulders! I've had my best luck browning the meat in added fat (LARD!!) in my heavy casserole, then I throw in onion and a bit of bouillon or wine and put the lid on, then a long sojourn in a slow oven. If you poke around in the meat when it's at room temperature (which it should be before you start anyway) you can pretty much tell if there are many fat pockets layered between the muscle groups and how well-filled they are. If the shoulder tests out lean under such an exam, I would not be above inserting slabs of bacon fat, or you could cut slices of half-frozen lard. After halfway dismantling it like this you'll want to tie it back up - PITA, I know, but what price porkiness?
What did you end up doing with it? If I were you, I'd throw a good amount of broth in there and return it to the oven. It might be too late, but perhaps you can get some moisture in?
Personally I think the roast was cooked too long. It continues to cook after being removed from the oven..... Did you put it into the roasting pan with that fat cap on top? I would have used a little EVOO for the moisture. We buy lean all natural pork from a local farm and I just roast it at 350 for 20 minutes a lb. OR - throw it into the slow cooker.... there's where you'll get the juicy stuff you crave.
A properly FAT pork shoulder is all but impossible to overcook. When the LA Times kitchen was testing their porchetta recipe, they pulled most of their shoulders out after from six to eight hours, but by way of experiment left one in for twelve. It looked much like what lunchbox described, but was perfectly succulent and delicious. Lean pork is in my eyes an essential denial of what pigs are about; anyone is perfectly free to disagree with that, but we were after all describing (and trying to correct) a problem with a piece of meat that was EXPECTED to be fat, and found to be not so.
My opinion why the roast turned out dry is a combination of a slightly high temperature, slightly too long in the oven and a piece of meat that was only four pounds. Combining all three factors together is culprit.
My thoughts are the meat should have been pulled sooner at about 5 hours and not 7. The Op is assuming the temperature is between 225-235*, but it is possible the oven was even hotter.....whenever I cook a pork shoulder roast my oven is set at 225* and over cooking has never occurred.....with a smaller 4 pound roast, I usually cook for 6 hours....and a larger 12-14 pound roast stays in the oven for a minimum 11 hours and sometimes as many as 14 hours total....this is all done without the use of a thermometer, but by simply pulling off a piece of meat to get the right feel to know when it's done........perfectly.
Here here! I've practically given up on many dry heat cooking methods for pork, though occasionally I come across cuts that have marbling like a meteor shower - then I indulge.