Whether it is a festive holiday gathering or a simple Sunday family dinner, a beautifully glazed ham often serves as the centerpiece of the meal. However, nothing dampens the spirit of a feast quite like a ham that is ice-cold in the middle or, conversely, as dry as a desert because it spent too much time in the heat. Mastering the timing and technique of heating up a ham is an essential skill for any home cook. Since most hams sold in grocery stores are already fully cooked or cured, your job isn’t really “cooking” the meat in the traditional sense, but rather “reheating” it to a safe and palatable temperature without sacrificing its natural juiciness.
Understanding Your Type of Ham
Before you even preheat your oven, you must identify exactly what kind of ham you have sitting in your refrigerator. The variety of ham determines the duration and method of heating.
Fully Cooked vs. Partially Cooked
Most hams you find at the supermarket are labeled “fully cooked.” This means the meat has already been heated to a safe internal temperature during processing. Your goal with a fully cooked ham is simply to bring it up to an enjoyable eating temperature, usually around 140 degrees Fahrenheit. If the label says “cook before eating” or “ready to cook,” it means the ham is only partially cooked or fresh. These require a significantly longer time in the oven and must reach a higher internal temperature of 145 degrees Fahrenheit to be safe for consumption.
Spiral Cut vs. Whole Ham
Spiral-cut hams are incredibly popular because they are pre-sliced all the way to the bone, making serving a breeze. However, because the meat is already sliced, it is much more prone to drying out. These require a lower temperature and a shorter heating window compared to a whole, uncut ham. A whole ham acts as its own insulator, retaining moisture better but requiring more time for the heat to penetrate to the center bone.
How Long to Heat Up Ham in the Oven
The oven is the gold standard for heating ham. It provides a steady, dry heat that can be mitigated with moisture-locking techniques like foil or roasting bags. For a standard fully cooked ham, you should generally plan for 10 to 15 minutes per pound.
Heating a Whole Fully Cooked Ham
If you are working with a whole ham (either bone-in or boneless), set your oven to 325 degrees Fahrenheit. Place the ham in a roasting pan with about half a cup of water, cider, or wine in the bottom to create a moist environment. Cover the pan tightly with aluminum foil. For a 10-pound ham, you are looking at approximately 2 to 2.5 hours of heating time. The key is to use a meat thermometer to ensure the thickest part of the ham reaches 140 degrees Fahrenheit.
Timing for Spiral Sliced Hams
Spiral hams are delicate. To prevent the slices from curling and drying, maintain the oven at 275 degrees Fahrenheit to 300 degrees Fahrenheit. Because the heat can penetrate the slices more easily, the timing is slightly different. Plan for about 10 to 12 minutes per pound. A 7-pound spiral ham will usually be ready in about 75 to 90 minutes. Many experts recommend placing the ham cut-side down in the pan to keep the moisture trapped within the slices.
Alternative Methods for Reheating Ham
While the oven is the most common tool, it isn’t the only way to get the job done. Depending on the size of your ham and the equipment you have available, other methods might be more convenient.
Using a Slow Cooker
The slow cooker is an excellent choice for smaller hams or if your oven is occupied by side dishes. This method is virtually foolproof for keeping the meat moist. Place the ham in the crockpot with a splash of liquid and cook on the “Low” setting. For a small 4 to 6-pound ham, it will take about 3 to 4 hours to reach the desired internal temperature. This is a “set it and forget it” method that works wonders for boneless hams.
The Electric Roaster Oven
If you are hosting a massive crowd and have a 20-pound ham, an electric roaster can save your kitchen. These units function similarly to a standard oven but are more efficient at maintaining moisture in a smaller enclosed space. Heat at 325 degrees Fahrenheit for about 15 minutes per pound. Ensure the lid remains closed to keep the steam inside, as every time you lift the lid, you add significant time to the process.
Essential Tips for Retaining Moisture
The biggest enemy of a reheated ham is evaporation. Since the fat has already been rendered to some degree during the initial cooking process, the lean protein can become stringy and tough if exposed to high heat for too long.
The Power of Aluminum Foil
Unless you are using a roasting bag, you should almost always wrap your ham or cover your roasting pan with heavy-duty aluminum foil. This creates a pressurized steam environment. If you want a crispy exterior or a glazed finish, you can remove the foil during the last 20 minutes of heating and crank the heat up to 400 degrees Fahrenheit briefly.
Adding Liquids to the Pan
Never put a ham in a dry pan. Adding just a small amount of liquid makes a massive difference. While water works, using pineapple juice, orange juice, or even a light beer can infuse the exterior of the meat with subtle flavors. As the liquid heats up, it creates steam that prevents the outer layers of the ham from turning into “ham jerky.”
Glazing Your Ham for Maximum Flavor
A glaze is more than just a sweet coating; it acts as a sealant. Most glazes contain sugar, which caramelizes under heat to create a delicious crust.
When to Apply Glaze
Do not apply your glaze at the beginning of the heating process. Most glazes have a high sugar content and will burn if left in the oven for two hours. Instead, wait until the ham is about 20 to 30 minutes away from being finished. Brush a generous layer over the surface and return it to the oven uncovered. You can repeat this process every 10 minutes to build up a thick, lacquered finish.
Temperature Check for Safety
While we often focus on the time per pound, the only way to be 100% sure your ham is ready is by checking the temperature. Use a digital meat thermometer. For a ham that was packaged in a federally inspected plant (most grocery store hams), 140 degrees Fahrenheit is the target. If you are reheating a “leftover” ham that has already been served once, the USDA recommends reheating it to 165 degrees Fahrenheit to ensure any bacteria introduced during previous handling are destroyed.
Frequently Asked Questions
Can I heat a ham from frozen?
It is not recommended to heat a ham directly from a frozen state. The outside will likely burn or dry out before the center even begins to thaw. For the best results, let the ham thaw in the refrigerator for 24 to 48 hours depending on its size. If you are in a rush, you can use a cold-water bath, changing the water every 30 minutes, but never use hot water.
How long can I keep a heated ham at room temperature?
Once your ham is heated and served, it should not sit at room temperature for more than two hours. If the ambient temperature is above 90 degrees Fahrenheit, that window shrinks to one hour. After the meal, carve the remaining meat off the bone and get it into the refrigerator quickly to prevent spoilage.
Does a boneless ham take less time to heat?
Yes, boneless hams generally heat faster than bone-in hams. The bone acts as a heat sink, requiring more energy to warm up the surrounding meat. For a boneless ham, you can usually stick to the lower end of the timing spectrum, roughly 10 to 12 minutes per pound at 325 degrees Fahrenheit.
Should I slice the ham before or after heating?
Unless you bought a spiral-cut ham, you should always heat the ham whole. Slicing the ham before heating increases the surface area exposed to the air, which leads to rapid moisture loss. Keep the ham intact as long as possible, then carve it immediately before serving.
How do I prevent the edges of a spiral ham from drying out?
The best trick for a spiral ham is to wrap it very tightly in foil and place it cut-side down in the pan. You can also place a few damp paper towels over the ham before wrapping it in foil to provide an extra moisture buffer. Avoid using the convection setting on your oven, as the moving air will dry out the slices faster.