Ham is a superbly versatile product, whether you treat it as the centerpiece of your meal or as a richly flavored ingredient in other preparations. It also freezes beautifully, so frugal shoppers can take advantage of any especially good price by purchasing extra. Of course, that means that you'll have to thaw the ham at some point to use it. Bacterial growth can occur at this stage, so it's important to know how to do it properly.
The Fridge Is Your Friend
The best way to thaw your ham or any other large item is in the refrigerator. The time it takes varies, but typically one day of thawing time for every 5 pounds of weight is a good rule of thumb. When in doubt, thaw your ham a day early; the extra day won't hurt it, and you won't have to wonder if it's fully thawed. Refrigerator thawing is safest because the entire ham remains at a food-safe temperature of 40 degrees Fahrenheit or lower, all the way through the thawing process. The bacteria responsible for foodborne illness are sluggish and dormant at that temperature and are unlikely to pose a risk.
When you don't have a day or two to spare, you can thaw your ham in a large pot or bowl of cold water instead. Change the water every 20 to 30 minutes until the ham is thawed. Thawing time depends largely on the shape of your ham, with flat cuts thawing more quickly, but you can expect a 5-pound ham to need at least 2 to 4 hours. Cook water-thawed hams on the same day. Microwave thawing is too uneven for large pieces of ham; you're better off to cook from frozen and simply extend your cooking time by 50 percent.