• Cut the pork loin into four pieces and place them in a 6 quart slow cooker. Sprinkle them with the chili powder, salt, and pepper, then pour the root beer into the slow cooker around the pork. Cover and cook for 6 to 8 hours on low, until the pork is very tender and easy to shred.

For the Sauce

• Meanwhile, make the sauce by combining the root beer, ketchup, orange juice, Worcestershire sauce, molasses, brown sugar, mustard, garlic, liquid smoke, onion powder and pepper in a large, heavy saucepan and whisking until smooth. Bring the mixture to a boil over medium heat, stirring occasionally. Reduce the heat to medium-low and simmer for 8-10 minutes to blend the flavors and reduce the sauce slightly. Season to taste with salt, if you feel it needs it, and additional black pepper. Remove the pan from the heat. Allow the sauce to cool slightly then transfer it to a bowl or other container with a tight-fitting lid and refrigerate it until you're ready to use it. The sauce can be made in advance and stored in an airtight container int he refrigerator for up to 1 week.
• When the cooking time is up, remove the pork to a large cutting board and discard all but about ½ cup of the cooking liquid. Use two forks to shred the pork then return it to the slow cooker with the reserved cooking liquid. Add as much of the Root Beer Barbeque Sauce as desired and toss with the shredded pork to combine. I usually add about ½ cup to 1 cup of the sauce and reserve the rest to serve on the side so people can make their sandwiches as saucy as they'd like.
• Cover and cook on low for an additional 30 minutes, until warmed through. Serve on toasted hamburger buns with additional Root Beer Barbecue Sauce on the side.