In fact, the heat inside is often as much as 45 degrees higher or lower than the thermometer reads, according to Cook’s Illustrated. In addition, ovens actually turn on and off while cooking, so even an accurate one will range by a few degrees during the cooking time. The result? Roast beef that’s over-cooked or undercooked, meatball subs with cheese that’s less than perfectly melty, or crostatas, like the one pictured above, that look, well, just not as good as that picture.
We all want our food to taste delicious and the directions on our recipes to yield dinner perfection, not frustration. To make sure you’re not being conned by your oven, we’ve got two solutions.
Buy an oven thermometer. An off-the-shelf dial oven thermometer costs about $12 and will reveal the true temperature of your oven. Like the oven’s own thermometer, these can become less reliable over time, but they’re easier to replace than your whole oven. (Ovens can be recalibrated by a professional.) When you start using it, you can compare what the new thermometer reads, versus what your oven asserts. Then, adjust the temperature up or down accordingly.
Use cues. To become a better chef, you have to tune into the smells, tastes, and textures of the food that you’re cooking, no matter what. (That’s also why we tell you to salt as you go.) In every recipe, we provide not just temperatures and times, but also clues about how your food should look, smell, and taste. For example, “Bake the crostata in the oven 12 to 15 minutes, or until the dough is cooked through.” That bolded clue is just as important to a good result as the more prescriptive direction that precedes it. See what we mean?
In our view, the best solution is to use these two techniques together. First, make sure your oven isn’t lying to you by picking up a new thermometer. Then, get in the habit of observing your food, so that you become a pro at picking up its cues.