Kielbasa, both fresh and fully cooked, are essentially two different foods in one – tender, ground-meat stuffing packed inside tough, thin, connective tissue – and requires two cooking methods for best results: gentle poaching for even cooking of the stuffing and high-temperature searing for a crispy, caramelized casing. You can do both poaching and searing on the grill. If you have fully cooked kielbasa, you can skip the poaching and go straight to the grill, because you're reheating, not cooking.

The ground meat in kielbasa takes longer to cook than the casing, and gives off a lot of steam. The casing, although porous, isn't quite porous enough to let that steam flow through it when it cooks at a high temperature; that's why kielbasa scorches and bursts when grilled over high heat for too long. And don't even think about piercing the casing; doing so drains a large portion of the creamy fat and juices, and hence, the flavor.

Cooking time differentiates grilling fully cooked kielbasa from fresh kielbasa; fully cooked kielbasa take about 10 to 12 minutes to cook, while fresh kielbasa takes twice as long. You do, however, need a meat thermometer for both; you must take them from the poaching liquid before they reach the safe-serving temperature of 165F so they don't burst when you sear them on the grill.

You obviously need a medium to poach in, but your choices are not just stock or water. If you plan on serving the kielbasa with sauerkraut and onions, you can add a little beer and cook everything in the same pan; the same goes for peppers and onions. If you plan on serving the kielbasa on its own, use just enough stock or water to reach about halfway up the sides of the sausages.

Set the grill to cook at medium-high heat. While the grill heats, add 1/2 pound of sauerkraut (for every 1 pound of kielbasa) to a 10-inch disposable roasting pan, and nestle the kielbasa in it. Add just enough lager or stock to reach halfway up the sides of the kielbasa.

Poach the kielbasa on the grill until they reach 140F. Place the roasting pan on the grill, and close the grill lid. It takes fresh kielbasa about 20 minutes to reach 140F and 10 minutes for fully cooked kielbasa to reach 140F. Turn the kielbasa over halfway over through cooking.

Sear the kielbasa until crisped and browned. It takes 2 to 3 minutes to sear both fully cooked and fresh kielbasa. If you're serving on hoagie rolls or buns, toast the buns off to the side of the grill, not over direct heat.