Roasted potatoes cooking on a baking sheet
The Primary Reason Your Potatoes Aren't Crisping Up In The Oven
Achieving roasted potatoes with a crisp exterior and velvety interior can be tricky. One sneaky factor that could ruin your dish is the way you place the spuds on a baking sheet.
Overcrowding a baking sheet with potatoes causes them to steam instead of brown as they release excess moisture, making them soft and bland instead of crispy.
The potatoes need space so that their moisture evaporates properly. Use two baking sheets, and arrange the potatoes in a single layer with some space between each piece.
Choose Yukon gold or russet potatoes for a perfect texture, with creamy interiors and crispy edges. Make sure your potatoes are cut into uniform pieces for even cooking as well.
You should use different roasting temperatures depending on your oven type. For convection ovens, 400-425 Fahrenheit is ideal, while 450 F is good for a conventional oven.
Place the baking sheets on the middle oven rack for even crisping. You can even parboil the potatoes with baking soda before roasting to remove starch and enhance crispness.