Cooking a ham is often the centerpiece of a holiday meal, a Sunday dinner, or a large family gathering. However, because most hams purchased at the grocery store are already “fully cooked” or “city hams,” the process isn’t really about cooking the meat from scratch. Instead, it is about reheating the ham so that it is hot all the way through without drying out the edges or ruining the texture. Knowing exactly how long to warm up a ham is the difference between a juicy, flavorful masterpiece and a salty, leathery disappointment.
Understanding Your Ham Type Before Heating
Before you can determine the timing, you must identify what kind of ham you have. The label on the packaging is your best friend here. Most hams fall into three categories: fully cooked, partially cooked, and fresh.
Fully Cooked Hams
These are the most common. They have been cured and smoked or boiled. You could technically eat them cold right out of the fridge, but they taste significantly better when warmed. Spiral-sliced hams almost always fall into this category.
Partially Cooked or Smoked Hams
These hams have been heated to a point where they are safe, but they still require further cooking to reach a palatable texture and flavor. They generally require more time in the oven than fully cooked varieties.
Fresh Hams
A fresh ham is an uncured leg of pork. This is not a “warming” situation; this is a full roasting process that can take several hours and requires reaching a much higher internal temperature than a pre-cooked ham.
The Standard Rule for Timing and Temperature
The gold standard for warming a fully cooked ham is to maintain a low and slow environment. If you blast the ham with high heat, the exterior will turn into jerky before the center even loses its chill.
For a standard oven set to 325 degrees Fahrenheit, you should plan on the following timeframes:
- Whole Ham (10 to 15 pounds): 15 to 18 minutes per pound.
- Half Ham (5 to 7 pounds): 18 to 24 minutes per pound.
- Spiral Sliced Ham: 10 to 15 minutes per pound.
The goal is to bring the internal temperature of the ham to 140 degrees Fahrenheit. This is the temperature recommended by the USDA for reheating pre-packaged ham. If you are reheating a “leftover” ham that wasn’t hermetically sealed at a plant, you should aim for 165 degrees Fahrenheit for safety.
Step-by-Step Instructions for Oven Warming
To ensure your ham stays moist during the long warming process, follow these steps.
Preparation and Room Temperature
Take the ham out of the refrigerator about 1 to 2 hours before you plan to put it in the oven. Letting it take the “chill” off allows for more even heating. If you put a rock-cold ham into a hot oven, the outside will overcook while the bone remains cold.
The Roasting Pan Setup
Place the ham in a heavy roasting pan. If it is a half-ham, place it cut-side down. This protects the largest surface area of the meat from direct heat and helps trap moisture inside.
Adding Moisture
Add about a half-cup of water, cider, or white wine to the bottom of the pan. This creates a steam-filled environment. Cover the entire pan tightly with heavy-duty aluminum foil. A tight seal is crucial; if steam escapes, your ham will dry out.
The Warming Process
Place the pan in an oven preheated to 325 degrees Fahrenheit. Use a meat thermometer to check the progress about 30 minutes before the calculated time is up.
Special Considerations for Spiral Sliced Hams
Spiral hams are incredibly convenient because they are pre-sliced down to the bone, making serving a breeze. However, those slices act like “fins” that allow moisture to escape rapidly.
To warm a spiral ham without drying it out, you must be extra vigilant. Some chefs recommend lowering the oven temperature to 275 degrees Fahrenheit and increasing the time slightly. This gentler heat prevents the thin slices from curling and hardening. If you use this lower temperature, expect the timing to increase to about 20 minutes per pound.
Using a Slow Cooker for Smaller Hams
If you have a smaller ham (usually under 8 pounds) and want to save oven space for side dishes, a slow cooker is an excellent tool. Because slow cookers use moist heat, they are very forgiving.
To use this method, place the ham in the crockpot with a splash of liquid. Cover and cook on the “Low” setting for 4 to 6 hours. Because every slow cooker varies in temperature, start checking the internal temperature at the 4-hour mark. You are still looking for that 140 degrees Fahrenheit internal reading.
How to Apply a Glaze Without Burning
The glaze is often the best part of the ham, providing a sweet or tangy contrast to the salty meat. However, most glazes contain high amounts of sugar, which burns easily.
Do not put the glaze on at the beginning of the warming process. Instead, wait until the ham has reached about 130 degrees Fahrenheit (usually the last 20 to 30 minutes of heating). Remove the foil, brush the glaze generously over the surface, and return the ham to the oven uncovered. You can even turn the heat up to 400 degrees Fahrenheit for these final minutes to caramelize the sugar, but watch it like a hawk.
Resting the Ham
Once the thermometer hits 140 degrees Fahrenheit, remove the ham from the oven. This is the most underrated step: let it rest. Tent the ham loosely with foil and let it sit for 15 to 20 minutes. This allows the juices to redistribute through the meat. If you cut into it immediately, the moisture will run out onto the carving board, leaving the meat dry.
Common Mistakes to Avoid
One common error is using a “High” setting on a slow cooker or a high temperature in the oven to speed things up. Ham is a dense muscle; heat takes time to penetrate to the bone. High heat only affects the surface.
Another mistake is forgetting to check the thermometer. No two ovens are calibrated exactly the same, and the shape of the ham (tall and narrow vs. short and wide) can change how the heat distributes. Always rely on internal temperature rather than the clock alone.
Summary of Timing for Quick Reference
If you are in a rush and need a quick mental checklist, remember these three numbers for a 325 degrees Fahrenheit oven:
- 10 minutes per pound for spiral hams.
- 15 minutes per pound for whole hams.
- 20 minutes per pound for half hams.
By following these guidelines, you ensure that your centerpiece is tender, warm, and delicious, making your meal a success.
FAQs
How long does it take to reheat a 10 pound ham?
In an oven set to 325 degrees Fahrenheit, a 10 pound whole ham will typically take between 2.5 and 3 hours to reach the required internal temperature of 140 degrees Fahrenheit. This assumes the ham is fully cooked and you have wrapped it tightly in foil to retain moisture.
Can I warm a ham in a roasting bag?
Yes, using a heat-resistant roasting bag is a very effective way to keep a ham moist. It traps all the steam and juices against the meat. If using a bag, follow the manufacturer’s instructions, but generally, the timing remains the same as the foil method (approximately 15 to 18 minutes per pound at 325 degrees Fahrenheit).
What is the best temperature to reheat a ham without drying it out?
The best temperature is a relatively low one, between 275 degrees Fahrenheit and 325 degrees Fahrenheit. Lower temperatures like 275 degrees Fahrenheit are ideal for spiral hams which are prone to drying, while 325 degrees Fahrenheit is standard for whole or half hams that are not yet sliced.
Do I need to add water to the pan when reheating ham?
While not strictly mandatory, adding about a half-cup of liquid (water, broth, or juice) to the bottom of the pan is highly recommended. This creates a moist environment that prevents the bottom of the ham from scorching and helps keep the meat succulent during the long warming process.
How do I reheat a ham if it is already sliced?
If the ham is already sliced into individual servings, do not put it back in the oven as a whole. Instead, place the slices in a baking dish, add a tablespoon of broth or water, cover tightly with foil, and heat at 325 degrees Fahrenheit for only 10 to 15 minutes. Alternatively, you can warm individual slices in a skillet over medium heat for 1 to 2 minutes per side.