From Prof Bill's successful experiment--approved by two certified chefs and a caterer who passed judgment on the final product:
This post is more about the sauce than it is about the pork roast. Most of you already know how to smoke a Boston butt--except in this case, the tenderloin is bone free and the last thing in the world you want is to serve guests or yourself is a bone-dry, tough as an old shoe, slice of roast--like pass the SOS pads! Gravy anyone? Consequently, the finish temperature must never exceed 145 F.
Pork Loin, Smoked 5.3 # Tie it into a round, long roast Smoke=Mesquite
BEFORE entry into the smoker:
Purchase two pork loins already tied (or you tie your own) into a large, round roast.
I sprinkled the loin roast with Daris' Steak Rub and added extra salt everywhere. I allowed 30 mins for spices to penetrate the roast and begin to bring it up to room temperature. I deliberately did not brine this roast as a test, since I have brined others before this one. Results: I probably will not brine another pork loin.
1. Start preheat of smoker to 220 F. Add a shelf-sized pan with ½ inch water and one (1) cup apple cider vinegar on the bottom shelf. [Note: DO NOT waste drippings!]
2. Start heating the biggest iron skillet or a Dutch oven to searing temperature and add ¼ cup canola oil or soybean oil as it heats. I prefer a cast iron skillet because I have better visual control over browning.
3. Blot dry the entire roast with paper towels—absolutely no moisture on the surface.
4. Brown/sear roast, on both ends first—easier to handle. Then brown the sides, turning as needed.
5. Once thoroughly browned, set the roast directly on a smoker shelf. I prefer to set the shelf on top of a plate to catch all the drips.
6. I coated the entire browned roast with Applebutter. [Note: Handling the roast from here on out will be messy!] I suppose applesauce would work, but I only had Applebutter—and I wanted the extra spices that make its full-bodied flavor.
Be sure to insert a remote-read meat thermometer into the roast, since that saves opening the door and losing all the heat and smoke to check temperature. Then, slide it into the preheated smoker. Good news exists now for all us old-timers who used to cook pork to death at 170 F. The USDA has changed the cooking temperature for pork to 145 F. Do not cook a degree longer, if you like moist, tender, succulent meat. The USDA also cut the rest time to three (3) minutes. Read more at: <http://www.fsis.usda.gov/wps/portal/fsis/topics/food-safety-education/get-answers/food-safety-fact-sheets/meat-preparation/fresh-pork-from-farm-to-table/CT_Index>
Temperature control note: I added my own internal temperature probe, which I had previously checked in boiling water at 212 F. against a mercury candy thermometer; both agreed to a within a degree. The Masterbuilt control "claims" the smoker temperature is 20 to 25 degrees hotter than the calibrated probe—see other blog posts that indicate the same problem. I wanted the smoking chamber cooking temperature to be 200 F. for 3 hours. From that point on, I physically monitored the roast temperature every 20-30 minutes until the remote read was at 145 F. I have had dry, shoe-leather, over-cooked pork loin roasts before that tasted like sawdust and tough as old shoes. This roast was tender, moist, slightly pink, and melted in my mouth.
Some purists would argue that placing a nearly shelf-sized pan of water on the bottom shelf, which is under the roast to be smoked, is unwise because the roast will not "smoke right" since the pan "blocks the smoke." Humbug! I argue that when the smoker is filled with smoke curling around inside the cooking chamber, the big drip pan hardly reduces the smoke-flow into the meat; at least that is my deliberate "operator licensed" choice, opinion, and taste proven fact. Secondly, as the 30-inch Masterbuilt smoker is designed—we owners know all too well about the drip catching design failure issues—I want every drip saved for the sauce, not dripping off into unrecoverable spaces below. Since pork tenderloin roasts are notably "mean &lean," and barely any fat exists, the dab of rendered fat remains a negligible ingredient in the drippings.
Once the loin roast was done to perfection and after the sauce was fully cooked, I loaded the roast into the Dutch oven with cooked sauce and kept it warm in the kitchen at 150—fully wrapped in aluminum foil to keep it warm, and prevent it from drying out into cotton balls.
Daris' Steak Rub
4 tsp. sea salt
2 tsp. paprika
1.5 tsp. ground black pepper
¾ tsp. onion powder
¾ tsp. ground cayenne pepper
¾ tsp. coriander
¾ tsp. turmeric