Step 1

In a bowl, whisk together the salt, paprika, brown sugar, cumin, cayenne and coriander.

Step 2

Rub the mix on the ribs, coating both racks completely. Transfer the racks to 2 large vacuum-seal bags and seal shut. Alternatively, place the ribs in sealable plastic bags and dip them into a large bowl of water to displace the air before sealing shut.

Step 3

Preheat a pot of water fitted with a sous-vide immersion circulator to 155 F according to the manufacturer's directions.

Step 4

Cook the ribs for 24 hours, making sure the bag remains completely submerged.

Step 5

The next day, remove the ribs from the bags and light a grill. Grill the ribs, flipping often, basting them with the barbecue sauce until lightly charred, 6 to 8 minutes.

Step 6

Transfer to a cutting board and carve, then serve.