Buying a fully cooked ham is one of the smartest moves a home cook can make, whether you are preparing a massive holiday feast or a simple Sunday dinner. Because the meat has already been cured and smoked (or boiled), the “cooking” process is actually more about reheating it to a safe, delicious temperature without drying it out. If you treat a pre-cooked ham like a raw piece of pork, you risk ending up with a salty, leathery main dish. However, with the right techniques, you can transform a standard grocery store ham into a succulent, glaze-dripping centerpiece.
Understanding Your Fully Cooked Ham
Before you even preheat the oven, it is essential to understand what you are working with. Most hams found in the meat aisle are labeled “fully cooked,” which means they have been heated to an internal temperature of at least 148°F during processing. You could technically eat them cold right out of the package, but most people prefer the texture and flavor of a warm, glazed ham.
There are three primary types of fully cooked hams you will likely encounter. The first is the city ham, which is wet-cured and usually sold vacuum-sealed in plastic. These are the most common and the easiest to reheat. The second is the spiral-sliced ham, which has been pre-cut in a continuous circle around the bone. These are incredibly convenient for serving but are the most prone to drying out because the heat can penetrate the slices more easily. Finally, there are boneless hams, which are formed into a round or oval shape. These are the easiest to carve but sometimes lack the depth of flavor found in bone-in varieties.
Essential Preparation Steps
To get the best results, you should take the ham out of the refrigerator about one to two hours before you plan to put it in the oven. Taking the chill off the meat allows it to heat more evenly. If you put a direct-from-the-fridge ham into a hot oven, the exterior will likely dry out before the center reaches the desired temperature.
While the ham is resting on the counter, take a moment to inspect it. If it is a whole or half ham that hasn’t been spiral-sliced, you may want to score the skin. Use a sharp knife to create a diamond pattern about a quarter-inch deep across the surface of the fat cap. This doesn’t just look beautiful; it allows your glaze to seep down into the meat and helps the fat render out during the reheating process.
The Best Way to Reheat: Low and Slow
The golden rule for how to cook a ham that is fully cooked is to use a low temperature. High heat is the enemy of a pre-cooked ham. You want to aim for an oven temperature of 325°F. This gentle heat warms the meat through to the bone without scorching the surface.
Place the ham in a heavy roasting pan. If you are cooking a half ham, place it flat-side down. This protects the most surface area from direct air contact. To create a moist environment, add about a half-cup of liquid to the bottom of the pan. Water works fine, but you can add flavor by using apple cider, pineapple juice, or even a splash of white wine.
Moisture retention is the next critical step. Wrap the entire roasting pan tightly with heavy-duty aluminum foil. You want to create a steam chamber that keeps the natural juices inside the meat. If you are using a roasting bag, follow the manufacturer’s instructions, but the foil method is a classic for a reason—it works perfectly for almost any size ham.
Timing and Temperature
Since the ham is already cooked, you are looking for an internal temperature of 140°F. This is the sweet spot where the meat is hot and the fats have softened, but the proteins haven’t begun to tighten and become tough.
Generally, you should plan for 15 to 20 minutes of oven time per pound of ham. For a standard 10-pound ham, this means about two and a half to three hours in the oven. However, every oven is different, and the shape of the ham (bone-in vs. boneless) can affect timing. The only way to be 100% sure is to use a meat thermometer. Insert it into the thickest part of the meat, making sure not to hit the bone, as the bone conducts heat differently and will give you an inaccurate reading.
Mastering the Glaze
The glaze is where you can truly make the ham your own. Most store-bought hams come with a little packet of glaze, but making your own is simple and far superior in flavor. A good glaze needs a balance of sugar and acidity.
Common bases include brown sugar, honey, or maple syrup. For the acidic component, consider Dijon mustard, apple cider vinegar, or citrus juice. Many people enjoy adding warm spices like ground cloves, cinnamon, or even a pinch of cayenne pepper for a little heat.
Timing is everything when it comes to glazing. Because glazes have a high sugar content, they will burn if they are in the oven for the entire cooking process. Wait until the ham has reached an internal temperature of about 120°F (usually about 30 to 45 minutes before it is finished). Remove the ham from the oven, increase the oven temperature to 400°F, and carefully remove the foil. Brush a generous layer of glaze over the entire surface. Return it to the oven uncovered and let it bake for another 15 to 20 minutes, brushing on more glaze every 10 minutes until a dark, sticky crust has formed.
Using the Slow Cooker Method
If your oven is occupied by side dishes, a slow cooker is an excellent alternative for reheating a fully cooked ham. This method is particularly effective for keeping the meat moist because the slow cooker traps steam naturally.
To do this, place the ham in the crock (you may need to trim a bit of the bottom if it’s too tall for the lid to close). Pour in your glaze or a cup of liquid like apple juice. Set the slow cooker to “Low” and heat for 4 to 6 hours. Because slow cookers use very low heat, this is one of the safest ways to ensure your ham stays tender, though you won’t get that same crispy, caramelized crust that an oven provides.
Carving and Serving
Once the ham reaches 140°F, remove it from the oven. This is the most difficult part: you must let it rest. Tent it loosely with foil and let it sit for at least 15 to 20 minutes. Resting allows the juices to redistribute throughout the meat. If you cut into it immediately, the moisture will run out onto the cutting board, leaving you with dry slices.
When carving a bone-in ham, cut slices perpendicular to the bone. For a spiral-sliced ham, the work is mostly done for you; you just need to cut along the natural fat lines and around the center bone to release the slices. Arrange the meat on a platter and spoon any remaining juices from the pan over the top to keep it glistening and moist.
Storing and Using Leftovers
Fully cooked ham stays fresh in the refrigerator for about 3 to 5 days. If you find yourself with more ham than you can eat in a week, it freezes beautifully. Wrap individual portions or slices tightly in plastic wrap and then aluminum foil to prevent freezer burn.
The best part of cooking a large ham is the leftovers. Diced ham is a perfect addition to morning omelets or breakfast casseroles. You can also use the ham bone—don’t throw it away!—to flavor a big pot of split pea soup or navy bean stew. The smoky flavor embedded in the bone will season a broth better than almost any other ingredient.
Frequently Asked Questions
Do I have to cook a fully cooked ham?
Technically, no. Since it is already fully cooked, it is safe to eat cold. However, reheating it enhances the flavor, softens the texture of the fat, and allows you to add a delicious glaze, which most people prefer for a main meal.
How do I stop a spiral-sliced ham from drying out?
Spiral-sliced hams dry out easily because the pre-cut slices allow moisture to escape. To prevent this, wrap the ham very tightly in heavy-duty foil, add a bit of liquid to the pan, and do not exceed an internal temperature of 140°F.
Can I cook a fully cooked ham from frozen?
It is highly recommended to thaw the ham completely in the refrigerator before reheating. Thawing can take 24 to 48 hours depending on the size. If you must cook from frozen, you will need to increase the cooking time by about 50 percent and keep it tightly covered to prevent the outside from drying out while the center thaws.
What is the best internal temperature for a reheated ham?
For a fully cooked ham that you are simply reheating, the USDA recommends an internal temperature of 140°F. If you are reheating a ham that was not processed in a USDA-inspected plant, it should be heated to 165°F.
Why is my ham so salty and how can I fix it?
Ham is naturally salty due to the curing process. If you are sensitive to salt, you can soak the ham in cold water for a few hours before cooking to leach out some of the brine. Alternatively, use a very sweet glaze containing honey or maple syrup to balance out the saltiness of the meat.