Whether it’s a centerpiece for a festive Christmas dinner or the star of a casual Sunday brunch, a succulent ham is a crowd favorite. However, because most hams purchased at the grocery store are already cured and fully cooked, the challenge isn’t actually “cooking” the meat—it’s reheating it without turning it into a dry, salty brick. Mastering the timing and temperature is the difference between a mouthwatering masterpiece and a kitchen disappointment.
Understanding Your Ham Type Before You Heat
Before you even preheat your oven, you must identify exactly what kind of ham you have sitting in your refrigerator. The timing for how long to heat ham in the oven depends entirely on its cut, size, and previous processing.
Fully Cooked vs. Cook-Before-Eating Hams
Most hams found in modern supermarkets are labeled as “fully cooked.” This means the meat has been cured and smoked or heated to an internal temperature that makes it safe to eat right out of the package. For these, you are essentially just warming them through to enhance the flavor and texture.
On the other hand, “cook-before-eating” hams require more time because you are bringing raw or partially cooked meat up to a safe internal temperature. These hams must reach an internal temperature of 145 degrees Fahrenheit followed by a three-minute rest.
Bone-In vs. Boneless
Bone-in hams generally offer superior flavor and moisture retention, but the bone acts as a heat sink, meaning it may take slightly longer for the center to reach the desired temperature. Boneless hams are more convenient for slicing and typically heat more evenly and quickly because they are more uniform in shape.
Spiral Sliced vs. Whole
Spiral-sliced hams are a massive time-saver for serving, but they are notorious for drying out. Because the meat is already cut down to the bone, heat can penetrate the slices more easily, which speeds up the process but also allows moisture to escape. Whole, unsliced hams take longer to heat but are naturally more protected from the dry air of the oven.
The Science of Oven Temperature
The secret to a juicy ham is low and slow. While it might be tempting to crank the oven up to 400 degrees Fahrenheit to get dinner on the table faster, high heat will toughen the exterior proteins before the center is even warm.
Most experts recommend a steady oven temperature of 325 degrees Fahrenheit. This provides enough heat to warm the meat efficiently while keeping the moisture locked inside the muscle fibers. If you are in a particular rush, you can go up to 350 degrees Fahrenheit, but you must be much more vigilant with your meat thermometer.
General Timing Rules for Reheating
When your oven is set to 325 degrees Fahrenheit, you can follow these general time estimates based on the weight of the ham:
- Whole Bone-In Ham (10 to 15 pounds): 15 to 18 minutes per pound.
- Half Bone-In Ham (5 to 7 pounds): 18 to 24 minutes per pound.
- Boneless Ham: 10 to 15 minutes per pound.
- Spiral Sliced Ham: 10 to 12 minutes per pound.
If you are heating a very small ham, such as a 2 or 3-pound boneless section, it may take as little as 30 to 45 minutes total. Always begin checking the internal temperature about 20 minutes before the estimated time is up.
Step-by-Step Instructions for Success
To ensure your ham stays moist, you should follow a specific preparation routine.
Preparation and Wrapping
Take the ham out of the refrigerator about 30 to 60 minutes before you plan to put it in the oven. Taking the chill off the meat allows it to heat more evenly. Place the ham in a heavy roasting pan. If you are using a half-ham, place it cut-side down to protect the interior meat.
Add about a half-cup of water, apple juice, or white wine to the bottom of the pan. This creates a moist environment. The most critical step is wrapping the pan tightly with heavy-duty aluminum foil. This prevents the steam from escaping, which is your best defense against dryness.
Monitoring the Temperature
The only foolproof way to know when your ham is done is by using a meat thermometer. For a fully cooked ham, you are aiming for an internal temperature of 140 degrees Fahrenheit.
Insert the thermometer into the thickest part of the meat, making sure not to touch the bone, as the bone will give you a false high reading. If you are heating a spiral-sliced ham, try to find a spot that hasn’t been sliced through to get an accurate reading of the core temperature.
Adding the Glaze
The glaze is what gives a ham its iconic “wow” factor. However, because glazes are usually high in sugar, they will burn if they are in the oven for the entire heating process.
Once 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. Carefully remove the foil, brush your glaze generously over the surface, and return it to the oven uncovered. Heat for another 10 to 15 minutes until the glaze is bubbling and caramelized.
Resting the Meat
Never slice a ham immediately after taking it out of the oven. Like any large roast, ham needs time to rest. During this 15 to 20-minute period, the juices redistribute through the meat. If you cut into it immediately, those juices will run out onto your cutting board, leaving the meat dry. Loosely tent the ham with foil during the rest to keep it warm.
Common Mistakes to Avoid
Many home cooks struggle with ham because of a few simple oversights.
- First, avoid the “set it and forget it” mentality. Every oven is calibrated differently. A ham that takes 2 hours in your neighbor’s oven might take 1 hour and 40 minutes in yours.
- Second, don’t skip the liquid in the pan. Even if the ham is wrapped in foil, that small amount of liquid creates a “braising” effect that is essential for maintaining the tender texture of the ham.
- Finally, don’t overheat. Once a fully cooked ham passes 145 degrees Fahrenheit, the texture begins to change from “tender” to “stringy.” Aim for 140 degrees Fahrenheit, knowing that the temperature will rise a few degrees during the resting phase.
Storage and Leftovers
If you find yourself with a significant amount of leftover ham, you should refrigerate it within two hours of serving. Sliced ham stays fresh in the refrigerator for 3 to 5 days. For longer storage, ham freezes beautifully. Wrap slices or chunks tightly in plastic wrap and then aluminum foil; it will maintain its quality in the freezer for up to two months.
FAQs
How long do I heat a 10 pound ham?
For a 10-pound bone-in ham at 325 degrees Fahrenheit, it will typically take between 2.5 and 3 hours. If it is a boneless 10-pound ham, it may take closer to 2 hours. Always use a meat thermometer to ensure the internal temperature reaches 140 degrees Fahrenheit.
Do I need to add water to the bottom of the roasting pan?
Yes, adding about a half-cup of liquid like water, broth, or juice is highly recommended. The liquid creates steam under the foil tent, which keeps the ham moist and prevents the outside from becoming tough and leathery during the long heating process.
Can I heat a ham in a slow cooker instead of an oven?
Absolutely. A slow cooker is an excellent way to heat a small or medium-sized ham, especially if your oven is occupied by side dishes. Place the ham in the slow cooker with a little liquid and cook on low for 4 to 6 hours. This method is particularly effective for keeping the ham moist.
Why did my spiral ham turn out dry?
Spiral hams dry out easily because the pre-cut slices allow moisture to evaporate from the center of the meat. To prevent this, ensure the ham is wrapped very tightly in foil, keep the oven temperature low at 325 degrees Fahrenheit, and do not exceed an internal temperature of 140 degrees Fahrenheit.
At what temperature is ham safe to eat?
For a “fully cooked” ham from the store, you are simply reheating it to a palatable 140 degrees Fahrenheit. However, if the label says “cook-before-eating” or “fresh ham,” you must cook it until it reaches a minimum internal temperature of 145 degrees Fahrenheit to ensure it is safe to consume.