Pour 1 gallon of cold water into a 12-quart plastic storage tub or stainless-steel bowl. Add the salt and sugar and stir until dissolved.
Put the pork belly in the brine, weighting them down with a plate to keep them completely submerged.
Cover the container and refrigerate for 24 hours.
Remove the pork from the brine, re-stir the brine a few times, and then return the pork to the brine and refrigerate for another 24 hours.
Drain the pork and discard the brine. Rinse the pork in cold water and pat dry. If using the black pepper, evenly sprinkle it all over the pork.
Cold-smoke the pork belly:
If using a charcoal grill, open all the vents. Remove the grill grate and put a 4×8-inch disposable foil loaf pan on the charcoal grate. Put 5 cups of the sawdust in the loaf pan.
If using a gas grill, disconnect the propane and put the pan on a back corner of the grill grate. (You won’t be lighting the burners since you are using the grill as a smoker.)
Light 5 charcoal briquettes. When the briquettes are glowing and completely covered with gray ash, transfer them with tongs to the sawdust, spacing them evenly in the pan. If using a charcoal grill, replace the grill grate.
When the sawdust begins to smolder, arrange the pork pieces fat side up on the grill grate to the side of the loaf pan.
Space the pieces at least 1 inch apart to allow the smoke to circulate around them. Cover the grill and insert a metal instant-read thermometer into a vent hole in the lid or lay it on the grate to monitor the grill temperature-it should be between 80°F and 120°F.
If the temperature rises above 120°F, remove 1 or more briquettes or partially uncover the grill until the temperature reduces.
Stir the sawdust with tongs every 1-1/2 hours to ignite any that’s unburned, and add more sawdust, 1 cup at a time, to the loaf pan as the sawdust turns to ash. You want a good amount of smoke rising out of the vents.
After 3 hours, rotate the position of the pork to ensure even smoking.
If your sawdust does stop burning, however, light more briquettes and reignite the sawdust.
The total smoking time will be 5 to 6 hours. Depending on the breed of pork and the duration of smoking, the bacon may become a brownish-yellow color. It will still be raw, however. The bacon will look dry on the meaty side, and the fat may be glistening with moisture.
Pat the moisture off with paper towels and cool the bacon completely at room temperature.
Refrigerate until firm before slicing.
You can store the bacon either in slices or large pieces (slabs).
To store sliced bacon, wrap the slices in small, individually wrapped batches. Tightly wrapped in plastic, bacon will keep in the refrigerator for up to 1 week, or in the freezer for up to 2 months. If you’ve frozen the bacon in slabs, let it defrost in the refrigerator for a couple of hours until it’s soft enough to slice with a sharp knife. (It’s easier to slice thinly when partially frozen.) Thaw completely before cooking.
Cook the bacon:
Fry your slices of bacon in a 12-inch skillet (preferably cast iron) over medium heat, turning frequently, until browned and as crisp or arrange in a single layer on a wire rack set over a large rimmed baking sheet and bake in a 350°F oven, turning once with tongs, until done to your liking.
Drain the bacon on paper towels and serve hot.