Make the curing solution: Combine 6 cups (1 1/2 quarts) water and the rest of the ingredients except the pork loin. Bring to a boil over high heat, stirring to dissolve the salts and sugar. Boil for 1 minute, then remove from heat and cool to lukewarm. 

Transfer the curing solution to a large container or brining bag and add the remaining 1 1/2 quarts (6 cups) water. Chill thoroughly in the refrigerator. Trim the loin of any excess fat and silverskin. Fully submerge the pork loin in the curing solution and refrigerate for 5 to 7 days.

Remove the pork loin from the curing solution and place it in a large container. Add enough fresh water to fully submerge it and let it sit for 30 min. Remove from the water and pat it dry with paper towels.

Heat smoker or grill to 225 to 250 degrees and add smoking wood chunks once it has reached temperature. While the smoker or grill is heating, if desired, use kitchen twine to tie the pork loin into a rounded shape. When the smoker or grill is smoking well, put the pork in the smoker and cook until an instant-read thermometer reaches 140 degrees when inserted in the thickest part of the loin, 2 to 3 hours. Let the pork loin cool for 30 minutes. Slice immediately and pan-fry, or cool it completely, slice as desired and freeze in serving-size packages.