The Parchment Paper Replacement Hack You Should Never Consider
Although you might see this "hack" on the internet, please, never place paper towels in the oven. If you run out of parchment paper when baking, you can not and should not use paper towels as a substitute . The recommendation that you can replace parchment paper with a paper towel — whether that's on a greased cake pan, under bread, on top of a pizza, or anywhere else in an oven — puts you at high risk of starting a fire. Not only is it incredibly dangerous, but it will also burn your food! A terrible idea all around.
Instead, consider using greased aluminum foil, a silicone baking mat, or making a quick trip to the store for more parchment paper. Silicone baking mats are going to be the best option: they're food-safe, reusable, oven safe to 500 degrees Fahrenheit, and they come in standard sheet pan and cake round shapes and sizes. If you're in a bind, just turn the oven off and run to the store for more parchment paper. When the alternative is starting a fire in your oven, the extra effort is worth it.
Little fires everywhere
Though Ray Bradbury might have you believing the ignition temperature of paper is 451 degrees Fahrenheit, that's not quite the whole story. Depending on factors like material, moisture, and thickness, paper can catch fire at higher or lower temperatures.
You might be thinking, "My oven will only be set to 325 degrees Fahrenheit, I should be fine." But this isn't a given, especially with an oily environment like a greased pan. Through a process called auto-oxidation, paper can actually "spontaneously" combust when in contact with carbon-based cooking oils like peanut, corn, soybean, canola, linseed (often used to condition cutting boards), lard, and margarine. This happens over the course of hours at room temp, but the rate of reaction doubles for every 50 degrees Fahrenheit rise in temperature — which you might notice is a key feature of baking.
Even if you're not greasing anything and whatever you're baking isn't oily, ovens have hot spots. Electric ovens can see temperature spikes of 5% to 15% in hot spots, and gas ovens can peak at 20%. A baking temp of 350 degrees Fahrenheit with a 20% variance could potentially put a paper towel into the lower ignition range — and that's assuming your oven thermometer is reading properly when set at 350 degrees Fahrenheit to begin with.
Worthwhile paper towel hacks for the kitchen
Obviously, paper towels are still incredibly useful in the kitchen. Whereas they can ruin your food in the oven, they can save your produce in the refrigerator. Excess moisture can be the bane of fresh vegetables, especially delicate leafy items like lettuce and fresh herbs. You can extend their shelf life by wrapping herbs in a paper towel and popping them into a container set in the crisper, or by placing a paper towel right into the box or bag of salad greens. If you have a drawer full of veggies, lining the drawer will help, too.
Unlike parchment paper, paper towels can be used in a bind if you run out of coffee filters (a much more dire situation than running out of parchment paper, honestly). Depending on the durability of the paper towels, you may want to double-layer them. If you're clarifying a milk punch, line your sieve with a paper towel for quicker draining than a coffee filter would offer.
If you have to decorate a cake but don't have a palette knife or offset spatula laying around, you can actually use paper towels to create a fondant-style finish. Instead of painstakingly smoothing buttercream with a bench scraper, take a smooth, non-patterned paper towel and place it on your frosting. Gently smooth your hand across the surface and then carefully pull the paper towel up from the frosting to reveal a near-perfect finish. Just keep them away from the oven.