Getting beneath the surface of cookie sheets
If cookware companies weren't around to entice us, we might never notice a few well-done edges on a tray of confections. Common sense dictates that a standard baking sheet - the rectangular, shallow-sided workhorse used for everything from roasting potatoes to broiling steaks - might also muster the requisite finesse for making a solid batch of cookies. Yet kitchen stores beckon with shelf upon shelf of "new" and "improved" designs: Nonstick! Insulated! Goldtouch! Pebbled! Give these souped-up cookie sheets a try, bakeware makers urge, and say goodbye to burnt-bottomed snickerdoodles and stubbornly stuck-on gingersnaps once and for all.
We took them up on the offer, and put a stack of cookie sheets through the paces. We even dropped a few bucks on one of those flimsy, disposable cookie sheets from the supermarket baking aisle. Hundreds of cookies and a few dozen biscuits later, we were surprised to find that our trusty professional half-sheet pan (it's like a sturdy jelly roll pan) may well have some competition when it comes to turning out pristine pecan sandies.
Although we always line baking sheets with parchment paper to keep cookies from sticking, we first tested a few nonstick sheets to see what we'd been missing. Not much, it turns out. The problem with nonstick bakeware is the dark color of the coating. Dark surfaces absorb heat more efficiently than light surfaces - too efficiently for baking cookies. In our tests, nonstick sheets produced cookies that over-browned on the bottoms long before the interiors cooked through. When we repeated the test using parchment paper, the results were identical.
These days, insulated sheets are all the rage. We certainly get the "rage" part. The pale-colored disks produced by these double-layered sheets were downright maddening. When a cookie bakes, it gets hit from two sources of heat: the ambient heat of the oven (this cooks the interior) and the direct heat of the sheet it's sitting on (this browns the bottom). With an insulated sheet, a hollow chamber below the surface fills with hot air, substantially diminishing the strength of the direct heat. That translated to cookies that over-browned on the top before the bottoms even began to crisp.
So far, our trusty half-sheet appeared to pass every test with flying colors. Who needs a special pan for cookies? But when we took a closer look during the sugar-cookie round, we reconsidered. All the cookies were lightly colored on top, but a few had browned unevenly. There was a definite pattern: Cookies positioned next to one of the four raised sides browned more aggressively on the section closest to the side. An inspection of the other sheets confirmed our theory. No matter how many raised sides the sheet had, the cookies positioned along them had browned unevenly. Extra heat bouncing off those sides was enough to create a hot zone.
With three contenders in a dead heat for top sheet, the edge went to the one with the fewest sides: the single-rimmed sheet by Doughmakers. Yes, cookies close to the single raised side tended to brown unevenly, but it was easy enough to fix: For later batches, we simply shifted the rows of cookies an inch or two away from the offending edge. The result? Nine perfect cookies. With a four-sided baking sheet, by contrast, there's no safe direction to shift.
A side issue, to be sure. But a crucial one.