If you are planning to make this using the air-fryer, make sure you check that your pork belly can fit into the air fryer basket first! Otherwise you will have to trim it so that it fits.
Rinse the pork belly and tweeze out any pig's hair you see/feel. Rinse again and pat-dry pork belly thoroughly with paper towels. Using a meat tenderiser needle tool, skewer or a fork, poke holes and make scratches all over the pork skin, making sure not to poke all the way through to the fats (see Note 3).
Turn the pork belly skin-side down. then rub Shaoxing wine lightly all over the pork meat and fat, making sure to leave the skin dry. Mix salt, five spice powder and white pepper in a small bowl. Rub the dry rub all over the pork meat and fat.
Place a large piece of aluminum foil on the table and place the pork belly, skin-side up, in the middle. Fold the aluminum foil to form a tin, making sure the meat is snugly fit inside the tin. Place it in the refrigerator, uncovered, overnight for at least 8 hours, up to 18 hours to dry out the skin.
The Day
Take the pork belly out from the refrigerator (no need to let it come to room temperature). Brush the skin with vinegar.
Combine plenty of coarse salt and a little bit of water so that the salt can pack together. Spoon the damp salt onto the pork skin. Press the aluminum foil against the meat and push the damp salt to the side, so that the salt covers the skin but don't fall into the aluminum tin. Repeat until all the skin has been covered with coarse salt.
(A) Oven Method
Preheat oven to 200°C.
Place the pork belly in the middle rack and bake for 45 minutes. Remove the pork belly from the oven. Preheat the broiler.
Carefully lift off the salt crust and brush off any remaining salt. Transfer the pork belly on a wire rack over the aluminum foil. The aluminum foil will catch the fat drippings, making cleanup easier.
Place the pork belly on the highest rack and broil until the skin is bubbly (like tumors) and crispy, which will take about 10 to 15 minutes.
(B) Air Fryer Method
Place pork belly in the air fryer basket. Air fry at 180°C for 35 minutes.
Carefully lift off the salt crust and brush off any remaining salt. Remove the aluminum foil and place the pork belly back in the air fryer basket. Air fry at 200°C for 10 to 15 minutes until the skin is crispy, checking every 5 minutes to make sure it's not burning.
Rest and Serve
Once the skin is crisp to your liking, remove the pork belly from the oven/airfryer. Let it rest on top of a rack anfor at least 15 minutes before chopping it.
Once cooled enough to handle, chop the pork belly into chunks (savour the moment when the skin cracks!) and serve with whatever you fancy!
Video
NOTES
Try to get a piece of pork belly of even thickness throughout from your butcher. I like to request for one that has slightly lesser fat.
Fine salt / fine table salt cannot be used for the salt crust.
Do not poke all the way through to the fats, otherwise the salt might seep through during baking, making your pork belly unpalatably salty. You just want to scratch the surface of the pork belly to encourage blistering during broiling. This step will take quite some time as you should try to poke as many holes as possible. Be patient and endure!
X and I can usually finish off the whole 500 grams of roasted pork between the two of us in one meal, (update in 2020: not anymore, our stomachs have shrunk!) but if you are going to serve it with a lot of other side dishes, this amount may be enough to feed 4 people.
When making a big batch, I would recommend cutting the meat (not the skin!) halfway before rubbing with Shaoxing and seasoning rub. This is so that the seasoning rub can penetrate into the meat better.