1. NOT PROPERLY CALIBRATED
An oven’s temperature matching its settings is key to creating tender baked goods and flaky pies. Your oven may need to be calibrated if an oven thermometer doesn’t detect the same temperature as the oven’s settings. Consult your owner’s manual or the manufacturer's website to learn more about how to calibrate your oven.
To use a manual oven thermometer, place it in the center of your oven’s middle rack, then preheat the oven and check the thermometer once the preheat is finished. If the manual thermometer’s temperature is 15 degrees above or below the oven’s programmed temperature setting, you may need to recalibrate your oven.