Preparing a holiday feast or a Sunday dinner often centers around a magnificent centerpiece, and few items are as reliable and delicious as a pre-cooked ham. Because the meat is already cured and smoked, your primary goal isn’t to “cook” it in the traditional sense, but rather to reheat it to a safe, succulent temperature without drying it out. Understanding how long cook a fully cooked ham is the difference between a leathery, salty disappointment and a tender, flavor-packed masterpiece that slides off the bone.
In this comprehensive guide, we will explore the nuances of timing, temperature settings, and various methods to ensure your ham stays moist and delicious. Whether you are working with a massive bone-in shank or a convenient spiral-sliced variety, the following sections will break down everything you need to know.
Understanding the Basics of Pre-Cooked Ham
When you purchase a ham from the grocery store, it is almost always labeled as “fully cooked” or “ready to eat.” This means the ham has already been heated to a temperature that kills bacteria, usually through a smoking process. However, eating a cold ham straight from the fridge isn’t usually the goal for a formal dinner.
The objective is to bring the internal temperature up to 140°F. If the ham was not processed in a USDA-inspected plant, guidelines suggest reaching 165°F, but for the vast majority of store-bought hams, 140°F is the magic number for peak juiciness.
Estimating Time Based on Weight and Type
The most critical factor in determining how long to leave your ham in the oven is its weight. As a general rule of thumb, you should plan for about 10 to 18 minutes per pound. However, the specific cut of the ham changes this estimate significantly.
Bone-In Fully Cooked Hams
A whole bone-in ham can weigh anywhere from 10 to 15 pounds. Because the bone acts as a conductor of heat but also adds mass, these hams require a steady, slow warming process. For a whole bone-in ham, set your oven to 325°F and plan for 15 to 18 minutes per pound. If you are only cooking a half-ham (either the butt or the shank end), the timing remains similar per pound, but the total time will be shorter due to the reduced weight.
Spiral Sliced Hams
Spiral sliced hams are incredibly popular because they are pre-cut for easy serving. However, they are the most prone to drying out because the heat can penetrate between the slices easily. To combat this, you should reduce the cooking time slightly. At 325°F, a spiral sliced ham usually takes about 10 to 14 minutes per pound. It is vital to keep these hams tightly wrapped in foil to trap moisture.
Boneless Hams
Boneless hams are compressed into a round or oval shape. Without the bone to worry about, the heat distributes more evenly through the meat. These typically require 15 to 20 minutes per pound at 325°F. Because they lack the protection of a bone, monitoring the internal temperature is even more important to prevent the texture from becoming rubbery.
The Importance of Oven Temperature
While it might be tempting to crank up the heat to 400°F to get dinner on the table faster, this is a recipe for a dry ham. The exterior will become tough and overcooked before the center even loses its chill.
The gold standard for reheating ham is 325°F. This temperature is high enough to warm the meat efficiently but low enough to prevent the natural sugars and fats from burning or evaporating too quickly. Some chefs prefer an even lower setting of 275°F or 300°F for an extra-slow “low and slow” approach, which can result in even more tender meat, though it will naturally increase your total time in the kitchen.
Step-by-Step Instructions for Reheating
To achieve the best results, follow this systematic approach. Preparation is just as important as the time spent in the oven.
- First, remove the ham from the refrigerator about 30 to 60 minutes before you plan to put it in the oven. Taking the chill off the meat allows for more even heating. If you put a dead-cold ham into a hot oven, the outside will inevitably overcook while the center remains cold.
- Second, prepare your roasting pan. Place the ham flat-side down. If it is a bone-in ham, try to position it so the fattiest side is facing up. As the fat renders, it will baste the meat naturally. Add about a half-cup of water, apple juice, or cider to the bottom of the pan. This creates a steamy environment that prevents the meat from dehydrating.
- Third, wrap the ham securely. Use heavy-duty aluminum foil to cover the entire ham or the roasting pan. You want to create a seal that keeps the moisture inside. This is the single most effective way to ensure a juicy result.
Adding a Glaze Without Burning
Many people want that iconic sticky, sweet crust on their ham. However, glazes usually contain high amounts of sugar, honey, or maple syrup, all of which burn very easily.
Do not apply the glaze at the beginning of the cooking process. Instead, wait until the ham has about 20 to 30 minutes left in the oven. At this point, remove the ham, take off the foil, and brush your glaze generously over the surface. Turn the oven up to 400°F or use the broiler setting for the last 5 to 10 minutes to caramelize the sugar. Watch it closely during this stage, as it can go from golden brown to burnt in a matter of seconds.
Using Alternative Cooking Methods
While the oven is the traditional choice, other appliances can handle a pre-cooked ham quite well, especially if you need to save oven space for side dishes.
Slow Cooker Method
A slow cooker is excellent for keeping a ham moist. For a small or medium-sized ham (usually 6 to 8 pounds), place it in the crockpot with a bit of liquid. Cook on Low for 4 to 6 hours. This method is very forgiving and almost guarantees a tender result, though you won’t get a crispy exterior.
Air Fryer Method
If you are cooking a small boneless ham or a few thick slices, the air fryer is surprisingly efficient. For a small 2 to 3 pound ham, wrap it in foil and cook at 300°F for about 30 to 40 minutes. It provides a nice texture on the outside while keeping the inside soft.
How to Tell When It Is Done
Visual cues and timers are helpful, but they aren’t foolproof. The only way to know for sure if your ham is ready is to use a meat thermometer. Insert the probe into the thickest part of the meat, making sure not to touch the bone, as the bone will give an inaccurately high reading.
Once the thermometer reads 140°F, remove the ham from the oven immediately. Keep in mind that “carryover cooking” occurs. The internal temperature will likely rise another 5 degrees while the ham rests on the counter.
Resting the Meat
One of the most overlooked steps in cooking a ham is the resting period. Once you pull the ham out of the heat, let it sit for at least 15 to 20 minutes before carving. This allows the juices to redistribute throughout the muscle fibers. If you cut into it immediately, all that delicious moisture will run out onto the cutting board, leaving the meat dry.
Frequently Asked Questions
How long should I cook a 10 pound fully cooked ham?
For a 10 pound bone-in ham, you should cook it for approximately 2.5 to 3 hours at 325°F. This is based on the estimate of 15 to 18 minutes per pound. Always check the internal temperature with a meat thermometer to ensure it has reached 140°F before serving.
Do I need to add water to the pan when reheating a ham?
Yes, adding a small amount of liquid like water, chicken stock, or fruit juice to the bottom of the roasting pan is highly recommended. The liquid creates steam under the foil cover, which helps maintain the moisture levels of the meat and prevents the bottom of the ham from scorching.
Should I cover the ham with foil the whole time?
You should cover the ham with foil for the majority of the cooking time to prevent it from drying out. However, if you are applying a glaze, you should remove the foil for the final 20 to 30 minutes of cooking. This allows the glaze to thicken and caramelize onto the surface of the meat.
Can I reheat a fully cooked ham from frozen?
It is not recommended to reheat a fully cooked ham directly from a frozen state. This will lead to uneven heating where the outside becomes overcooked and dry while the inside remains cold or frozen. For the best results, thaw the ham completely in the refrigerator for 24 to 48 hours before you plan to reheat it.
What is the best oven temperature for reheating a spiral ham?
The best temperature for a spiral sliced ham is 325°F. Because spiral hams are already sliced, they lose moisture faster than uncut hams. Keeping the temperature at 325°F and ensuring the ham is tightly wrapped in foil will help protect the delicate slices from becoming tough.