Cooking a ham is often the centerpiece of holiday gatherings, Sunday dinners, and festive celebrations. However, because most hams purchased at the grocery store are labeled as “fully cooked,” the process is less about cooking and more about reheating. The goal is to bring the meat to a palatable serving temperature without drying it out. Understanding the nuances of timing, temperature, and technique is essential to ensuring your ham remains juicy, flavorful, and tender.
Understanding the Fully Cooked Ham
Before diving into the specific timing, it is important to clarify what “fully cooked” actually means. Most hams sold today are cured—meaning they have been treated with a salt and sugar brine—and then smoked or baked by the processor. When you bring it home, the meat is technically safe to eat straight out of the package. However, a cold ham lacks the aromatic appeal and succulent texture of one that has been properly warmed and glazed.
Because the meat is already “done,” your primary enemy is evaporation. If you leave a ham in the oven for too long or at a temperature that is too high, the muscle fibers will tighten and the moisture will escape, leaving you with a leathery dinner. Success depends on a low-and-slow approach that preserves the integrity of the meat.
Determining the Right Oven Temperature
The standard recommendation for reheating a fully cooked ham is to set your oven to 325 degrees Fahrenheit. This temperature is high enough to penetrate the dense meat efficiently but low enough to prevent the exterior from burning before the center is warm. Some cooks prefer an even lower temperature of 275 degrees Fahrenheit or 300 degrees Fahrenheit if they have a particularly large ham and plenty of time, as this further reduces the risk of dryness.
How Long Do You Cook a Fully Cooked Ham per Pound?
Timing is largely dependent on the weight of the ham and whether it is bone-in or boneless. While every oven varies, you can use these general benchmarks to plan your meal prep.
For a whole, bone-in ham, you should plan for approximately 15 to 18 minutes per pound. If you are preparing a half bone-in ham, which usually weighs between 5 and 10 pounds, the timing stays roughly the same, often leaning toward the 18 to 20-minute mark per pound because there is less mass to retain heat compared to a massive whole ham.
If you have purchased a boneless ham, the process is slightly faster. Because there is no bone to act as an insulator, the heat penetrates the meat more uniformly. Expect a boneless ham to take about 10 to 15 minutes per pound.
Spiral-sliced hams require special attention. Because the meat is already sliced down to the bone, the surface area exposed to the air is much higher. This makes it very easy for the ham to dry out. For a spiral-sliced ham, you should aim for the lower end of the spectrum, roughly 10 to 12 minutes per pound at 325 degrees Fahrenheit.
Monitoring the Internal Temperature
While time-per-pound estimates are helpful for planning, the only way to guarantee a perfect result is to use a meat thermometer. According to food safety guidelines, a pre-cooked ham should be reheated to an internal temperature of 140 degrees Fahrenheit.
If you are dealing with a ham that was not packaged in a USDA-inspected plant (such as one from a local farm that might not be fully “ready-to-eat”), it is safer to bring it to 165 degrees Fahrenheit. However, for the vast majority of store-bought hams, 140 degrees Fahrenheit is the magic number for peak juiciness.
Preparation Steps for Maximum Moisture
To ensure your ham doesn’t lose its moisture during the reheating process, there are several preparatory steps you should take before putting it in the oven.
- First, take the ham out of the refrigerator about 1 to 2 hours before you plan to cook it. Bringing the meat closer to room temperature allows for more even heating. If you put a dead-cold ham into a hot oven, the outside will become overcooked by the time the center reaches 140 degrees Fahrenheit.
- Second, use a roasting pan with a small amount of liquid in the bottom. Adding about a half-inch of water, apple juice, or cider to the bottom of the pan creates a humid environment. This steam helps keep the meat supple.
- Third, wrap the ham tightly. You can cover the entire roasting pan with a heavy-duty aluminum foil tent. This traps the moisture inside. For spiral hams, some even recommend wrapping the ham itself in foil before placing it in the pan to ensure no steam escapes the pre-cut slices.
The Art of Glazing
A glaze is what transforms a standard ham into a spectacular centerpiece. Most hams come with a glaze packet, but making your own with brown sugar, honey, Dijon mustard, and spices is a simple way to elevate the flavor.
Because glazes contain high amounts of sugar, they will burn if they are in the oven for the entire cooking duration. The rule of thumb is to apply the glaze during the last 20 to 30 minutes of cooking.
When the ham reaches an internal temperature of about 130 degrees Fahrenheit, remove it from the oven and increase the oven temperature to 400 degrees Fahrenheit. Brush the glaze generously over the surface, making sure it gets into the crevices. Return it to the oven uncovered and bake until the glaze is bubbly and caramelized and the internal temperature has reached the final 140 degrees Fahrenheit goal.
Cooking Methods Beyond the Oven
While the oven is the most traditional method, it is not the only way to reheat a fully cooked ham.
- The slow cooker is an excellent option for smaller hams (usually 5 to 8 pounds). Because the slow cooker is a sealed, moist environment, it is almost impossible to dry out the meat. Place the ham in the crockpot with a splash of liquid and cook on low for 4 to 6 hours.
- If you are short on oven space, a roaster oven works identically to a standard oven but sits on your countertop. Follow the same time and temperature guidelines of 325 degrees Fahrenheit for 15 minutes per pound.
- For those who enjoy a smoky flavor, you can reheat a ham on a grill or in a smoker. Use indirect heat and maintain a temperature of 300 degrees Fahrenheit. This method adds a layer of “wood-fired” complexity to the pre-smoked meat.
Resting the Meat
One of the most overlooked steps in cooking a ham is the resting period. Once the ham reaches its target temperature, remove it from the oven and let it sit, loosely tented with foil, for at least 15 to 20 minutes.
Resting allows the juices to redistribute throughout the meat. If you carve it immediately, the moisture will run out onto the cutting board, leaving the meat dry. Resting also allows the internal temperature to rise slightly (a phenomenon known as carry-over cooking), ensuring the center is perfectly warm.
Common Mistakes to Avoid
The most frequent mistake is “over-cooking the cook.” Remember that you are not trying to reach a “done” state like you would with a raw chicken or a pork roast. You are simply warming it.
Another mistake is neglecting to check the thermometer in multiple spots. If you have a bone-in ham, make sure the thermometer does not touch the bone, as the bone conducts heat differently and will give you a false reading. Always check the thickest part of the meat.
Lastly, avoid using high heat. It is tempting to crank the oven to 400 degrees Fahrenheit to speed things up, but this will almost certainly result in a dry ham with a burnt exterior. Patience is the key ingredient.
Summary of Reheating Times
To keep things simple, here is a quick reference for a 325 degrees Fahrenheit oven:
- Whole Bone-in Ham (10 to 14 lbs): 15 to 18 minutes per pound.
- Half Bone-in Ham (5 to 7 lbs): 18 to 22 minutes per pound.
- Boneless Ham (5 to 10 lbs): 12 to 15 minutes per pound.
- Spiral Sliced Ham (7 to 9 lbs): 10 to 12 minutes per pound.
By following these guidelines, you ensure that your fully cooked ham remains the star of the show—tender, moist, and perfectly seasoned.
Frequently Asked Questions
Can I eat a fully cooked ham without reheating it?
Yes, you can safely eat a fully cooked ham cold, straight from the refrigerator. Because it has been cured and pre-cooked by the manufacturer, it is ready-to-eat. However, most people prefer to reheat it to enhance the flavor and texture for a main course meal.
How do I keep a spiral ham from drying out?
The best way to keep a spiral ham moist is to wrap it tightly in aluminum foil and place it cut-side down in a roasting pan with a bit of water or juice. Cook it at a lower temperature, around 300 degrees Fahrenheit or 325 degrees Fahrenheit, and avoid overcooking it past an internal temperature of 140 degrees Fahrenheit.
Do I need to add water to the bottom of the pan?
While not strictly required, adding about a half-inch of liquid (water, broth, or juice) to the bottom of the roasting pan is highly recommended. The liquid creates steam that helps prevent the meat from drying out during the long reheating process.
What should I do if my ham is still frozen?
It is best to thaw a ham completely in the refrigerator before reheating. This usually takes about 4 to 6 hours per pound. If you must cook it from frozen, you will need to increase the cooking time by approximately 50 percent and keep it tightly covered to prevent the outside from drying out while the inside thaws and heats.
How long can I keep leftover ham in the fridge?
Leftover cooked ham can be stored in an airtight container in the refrigerator for 3 to 5 days. If you cannot finish it within that timeframe, you can freeze it for up to 2 months for best quality, though it remains safe to eat indefinitely while frozen.