Wrapping baked potatoes in foil isn't really necessary, but if you choose to wrap them, plan on baking for 45 minutes to one hour, depending on your cooking method and the size of the potatoes. The larger the potatoes you choose, the longer you'll need to bake them. Also, if you plan on baking a lot of potatoes, that may also increase the cooking time. Choose unblemished, firm Russet potatoes without any green spots, which are caused by exposure to sun and light.
Standard Baking Time
The traditional way to bake potatoes wrapped in foil is on the oven rack at 425 F. Clean and pat dry your potatoes, and then prick your potatoes with a fork before you wrap it with foil. The fork pricks will help steam escape the potato as it bakes. When baked at this temperature, the potatoes should be done in 45 to 60 minutes, or when the internal temperature of the potato reaches 210 F. Large potatoes will take longer.
If you use the convection feature on your oven, you can cut cooking time down about 25 percent, and you can also reduce the oven temperature by 25 F. Convection ovens work by blowing hot air over and around the food so it cooks quickly and evenly. Expect baked potatoes wrapped in foil to take between 30 and 45 minutes in a convection oven.
Slow Cook Method
If you've got time to spare, try cooking baked potatoes in a slow cooker. Slow cookers steam the potatoes so they come out tender and moist. Wash, pat dry and wrap the potatoes in foil and place them in the bottom of the slow cooker so the cooker is two-thirds full. Cover and cook the potatoes on low for eight to 10 hours.
To Use Foil or Not
Wrapping potatoes in aluminum foil is one of those cooking techniques that's been passed down for many years, but you might be wondering if it's really necessary. Wrapping potatoes in foil does keep the potatoes hot longer after you remove them from the oven, which is a good option if you're entertaining and need an easy way to keep food warm before a meal. On the other hand, wrapping potatoes in foil causes them to steam instead of bake so they lack the crisp skin and fluffy texture most people prefer. Whether you choose to wrap potatoes or not, be sure to prick them with a fork so steam escapes. You can also salt the skins and rub them with olive oil before wrapping them for more flavorful potatoes.