Brining pork in a water-and-salt solution results in juicy, tender meat. A good rule of thumb for water-to-salt ratio is for every 4 cups of water add around 1/4 cup of salt. Make enough brine to completely submerge the ham. Fresh herbs and sugar, the same amount as the salt, also can be added. Keep the ham in the refrigerator while brining. Brine an 18-pound fresh ham for approximately 6 to 12 hours. When you’re ready to cook it, remove the ham from the brine, rinse, pat it dry and let it come up to room temperature, which takes about 30 minutes.
Whether you slow-cook a fresh ham on the barbecue or in the oven, the methods are basically the same. When you insert a meat thermometer into the ham, avoid touching the bone. Cook the ham fat side up. For grilling, only light one side of a gas barbecue, or move hot coals to one side; add charcoal as needed to maintain heat. Place a drip pan under the unlit side of the grill, and put the ham on that side. Close the lid. For oven roasting, place the ham in a roasting pan. Cover the ham loosely with foil. After you remove the ham from the barbecue or oven, let it rest before carving. This helps the meat retain its juices.
To add flavor, spread glaze over the ham during the last half-hour of cooking. Glazes usually consist of some type of sweetener, which helps give the ham a caramelized color. Typical sweeteners used in glazes include brown sugar, fruit juices and honey. Mustard glaze, a classic, complements ham. For this glaze, combine brown sugar, prepared mustard, orange juice and a dash of cayenne pepper if desired. You also can blend honey, pineapple juice and ginger for a tropical-flavored ham glaze.
A paste of lemon, garlic and rosemary produce a fragrant ham. Unlike a glaze, the paste is spread on the ham before roasting. Scoring the ham first results in a presentation-worthy roast, but avoid cutting into the meat. Always place the ham fat side up in your roasting pan, and then score the fat into a diamond pattern. Spread the ham with a paste made with lemon zest, chopped fresh rosemary, olive oil, chopped garlic, Kosher salt and black pepper. The paste can be made in the food processor, or with a mortar and pestle. Cover the ham with foil and roast it for approximately three hours. Then, uncover the ham, drizzle with white wine and roast and baste it until it's done. A safe internal temperature for fresh ham is 160 degrees Fahrenheit; the temperature must hold for 15 seconds.