Rinse rib racks under cold water and pat dry with paper towels. Place 1 rack vertically on a cutting board, bone-side up. Use a butter knife or your finger and slide it under the 'silverskin' (white membrane) on one end of the rack. Loosen it a bit until you have enough grip to hold with your fingers (or use a paper towel for more grip) and pull it off the ribs. Do this until all of the silverskin is removed. Repeat for rack #2.
Cut between each rib bone to separate ribs into individual pieces. Place into a large mixing bowl and set aside.
In a medium mixing bowl add garlic, lemongrass, brown sugar, fish sauce, apple juice and sake. Stir to combine and pour into meat bowl. Mix meat with marinade to combine, cover with plastic wrap and refrigerate for 2 hours (or up to 24 hours).
Preheat grill to 350°F. Place ribs meat side down and grill for 10 minutes. Flip ribs over and grill for another 10 minutes. Repeat this step until meat is fully cooked and golden brown. Check rib doneness by inserting a meat thermometer (without touching the bone) and internal temperature reads 195°F (90.6°C).
Serve over a bed of rice with green beans or with your favourite sides.