When I'm writing a recipe for cookies, I always make a point of expressly calling for a parchment-lined baking sheet. Details like this may be easy to gloss over, but they can make a big difference in how a cookie turns out. Whenever a reader writes in asking me to troubleshoot cookies that spread too much, browned too much, and turned out greasier than those pictured in the recipe, my first question is almost always "Were they baked on silicone?"
More often than not, the answer is yes.
Excess spread can be caused by other issues (particularly under-creaming the butter and sugar), greasiness can relate to problems with butter and flour style, and over-browning can relate to wonky baking soda measurements or dark baking sheets. But when these three complaints show up together, the culprit is almost always silicone.
Check it out.
Above, we have my thin and crisp Tate's-style chocolate chip cookies, baked on parchment. Below, cookies from the same batch of dough, baked in the same oven, on the same rack, for the same length of time, but on a silicone baking mat.
The difference in browning and spread is extreme. While some folks may think the second tray has an allure of its own, that mystique will disappear with a single bite: The cookies baked on silicone are dense and greasy, with a dull crunch, and a hint of bitterness from excessive browning.
That's because silicone affects how heat is conducted to the dough, and its nonstick surface allows for more spread. Because the dough spreads faster, it bakes faster and puffs less, resulting in browner, denser cookies lacking the delicate crunch and honeycomb crumb of a cookie that rose in the oven as intended.
Because silicone isn't as breathable as parchment, cookies left to cool on the baking sheet can also sweat along their bottoms, which does no favors for their texture, whether said cookie is meant to be crunchy or soft.
In cookies that are designed to spread, accelerating that process can exaggerate the effects of silicone; in those that are meant to stay thick and fluffy, the results may be more subtle.
Baked on silicone, however, they spread more and thin out around the edges, turning crisp.
This characteristic may appeal to some bakers, but it's not how the cookies are meant to turn out, and anyone craving a soft and tender sugar cookie would be sorely disappointed to encounter an epic crunch.
For me, there are no occasions when baking on silicone is preferable to using parchment. For those who don't trust my judgment, know that Alton Brown himself feels the same way, going so far as to say he vastly prefers parchment.
And, if you're concerned about minimizing waste in the kitchen, your piece of parchment is more than a one-hit wonder. A quick wipe with a cloth will get rid of any grease or debris, meaning that a single sheet can be reused almost as many times as you care to keep it around. Plus, many brands of unbleached parchment paper are compostable as well (including Reynolds and If You Care) or else biodegradable (such as PaperChef).
I'm not saying there aren't some bakers out there who prefer silicone, or enjoy the differences that it can produce! Only that when cookies don't turn out how they should, it's worth exploring the small but important details that may have been neglected along the way.