Purchasing a precooked ham is one of the smartest moves a home cook can make, especially during the hectic holiday season or for a large Sunday dinner. Because the meat has already been cured and smoked or boiled, your job isn’t really to “cook” it in the traditional sense, but rather to reheat it to a safe, delicious temperature without drying it out. The challenge lies in the timing; leave it in too long, and you have expensive jerky; take it out too soon, and the center remains unpleasantly cold.
Understanding the Precooked Ham Label
Before you even preheat your oven, you need to look at the packaging. Most hams sold in grocery stores are labeled as “fully cooked,” but there is a nuance you should be aware of. A “fully cooked” ham can technically be eaten cold straight from the package, while a “ham that requires cooking” (often partially cooked) must reach a higher internal temperature to be safe.
For the purpose of this guide, we are focusing on the standard fully cooked variety. These hams are usually wet-cured or smoked, providing that classic pink hue and salty-sweet flavor profile. Knowing whether your ham is bone-in or boneless will also significantly impact your calculation for how long to cook precooked ham.
General Time and Temperature Guidelines
The gold standard for reheating a precooked ham is a low and slow approach. You want to maintain the moisture while allowing the heat to penetrate deep into the bone.
For a standard oven set to 325°F, you should plan for about 15 to 20 minutes per pound. If you have a large 10-pound ham, this means you are looking at a total time of roughly 2.5 to 3 hours.
Boneless vs Bone-In Timing
Bone-in hams tend to have more flavor and stay juicier, but the bone acts as a heat conductor. Surprisingly, bone-in hams often require slightly less time per pound than a very dense, large boneless ham, though the difference is minimal.
- Boneless Ham: Plan for 15 to 20 minutes per pound.
- Bone-In Ham: Plan for 18 to 22 minutes per pound.
- Spiral Sliced Ham: These are precut and very susceptible to drying out. They generally need only 10 to 15 minutes per pound at a lower temperature like 275°F or 300°F.
The Importance of Internal Temperature
While time-per-pound estimates are a great starting point, they are not foolproof. Every oven has hot spots, and the starting temperature of the meat (straight from the fridge versus sitting on the counter for 30 minutes) can change the outcome.
According to USDA food safety guidelines, a precooked ham should be reheated to an internal temperature of 140°F. If the ham was not packaged in a USDA-inspected plant (for example, a ham you bought from a local farm or butcher that wasn’t processed in the standard commercial way), you should aim for 165°F to be safe. However, for 99% of store-bought hams, 140°F is the magic number for peak juiciness.
Preparation Steps for Maximum Moisture
To ensure your ham doesn’t turn into a salt brick, preparation is key. Start by taking the ham out of the refrigerator about 30 to 45 minutes before you plan to put it in the oven. This takes the chill off the meat and allows for more even heating.
Place the ham in a roasting pan. If it is a “city ham” (the standard half-moon shape), place it flat-side down. This protects the interior meat from direct heat exposure. Add about a half-inch of liquid to the bottom of the pan. You can use water, but apple juice, pineapple juice, or even a splash of ginger ale adds a lovely aromatic quality to the steam.
Cover the entire pan tightly with heavy-duty aluminum foil. This is the most critical step in the “how long to cook precooked ham” process. The foil traps the steam generated by the liquid, effectively braising the ham as it reheats.
Scoring and Glazing Your Ham
A ham isn’t truly a centerpiece without a beautiful, sticky glaze. However, timing the glaze is where many people go wrong. If you put a sugar-heavy glaze on at the beginning of a three-hour cook, it will burn and turn bitter.
Wait until there are about 20 to 30 minutes left in the reheating process. Remove the ham from the oven and increase the temperature to 400°F. Carefully remove the foil. If the ham isn’t already spiral-sliced, use a sharp knife to score the fat in a diamond pattern, about a quarter-inch deep.
Brush your glaze generously over the surface, ensuring it gets into the scores or between the slices. Put the ham back in the oven uncovered. Keep a close eye on it; you want the sugar to bubble and caramelize into a dark amber color, but it can go from perfect to burnt in a matter of minutes.
Alternative Cooking Methods
While the oven is the traditional choice, other appliances can handle the task of reheating a precooked ham quite well, often with different timing requirements.
Slow Cooker Method
The slow cooker is excellent for keeping a ham moist because it creates a sealed, humid environment. This is best for smaller hams (under 8 pounds) that can actually fit under the lid.
- Time: 4 to 6 hours on Low.
- Benefit: Frees up oven space for side dishes.
Air Fryer Method
If you are cooking a small boneless ham or a ham steak, the air fryer is incredibly efficient.
- Time: Approximately 10 minutes per pound at 300°F.
- Warning: You must wrap it tightly in foil, or the high-velocity air will dry the exterior out instantly.
Resting the Meat
Once the ham reaches that 140°F internal mark, remove it from the oven. Do not slice it immediately. Just like a steak or a turkey, ham needs time to rest. Transfer it to a cutting board and tent it loosely with foil for 15 to 20 minutes. This allows the juices to redistribute throughout the muscle fibers. If you cut it right away, the moisture will pour out onto the board, leaving the meat dry.
Common Mistakes to Avoid
The most common mistake is cooking at too high a temperature. Because the ham is already cooked, you are not trying to “sear” it or break down tough connective tissues. High heat simply tightens the proteins and squeezes out the water. Stick to 325°F for the bulk of the time.
Another mistake is forgetting to check the thermometer. If you rely solely on the clock, you might overcook a smaller-than-average bone or a ham with a higher fat content. Start checking the internal temperature when you have about 45 minutes of estimated time remaining.
FAQs
How long do I cook a 5 lb precooked ham?
For a 5-pound fully cooked ham, you should cook it at 325°F for approximately 75 to 100 minutes (1 hour 15 minutes to 1 hour 40 minutes). Always verify that the internal temperature has reached 140°F before removing it from the heat.
Should I wrap the ham in foil while reheating?
Yes, it is highly recommended to wrap the ham tightly in aluminum foil or cover the roasting pan with a tight foil lid. This prevents moisture from evaporating, ensuring the ham remains tender and juicy rather than becoming tough and dry.
Can I cook a precooked ham from frozen?
It is not recommended to cook a ham directly from a frozen state. It will result in an unevenly cooked meat where the outside is overdone and dry while the center remains cold. It is best to thaw the ham in the refrigerator for 24 to 48 hours before reheating.
How do I keep the ham from drying out?
Beyond wrapping it in foil, adding a small amount of liquid (water, broth, or fruit juice) to the bottom of the roasting pan creates a steam-filled environment. Additionally, keeping the oven temperature low (around 325°F) is essential for moisture retention.
What is the difference between a city ham and a country ham?
A city ham is what most people find in the grocery store; it is wet-cured and fully cooked, requiring only reheating. A country ham is dry-cured with salt, often aged for months, and has a much saltier, funkier flavor. Country hams often require soaking in water for 24 hours before they are even ready to be cooked.