Kenji Lopez-Alt shares the science behind cooking some of our favorite dishes in his book, "The Food Lab." Here, he offers his rules for making a smash burger, and why we should all be making burgers this way!
Rule 1: Use a stiff, sturdy spatula
No flexible spatulas or cheap plastic ones here. You need a heavy-gauge stainless steel spatula with a fully riveted handle.
Rule 2: Use a heavy stainless steel or cast-iron skillet
The goal is steady, even heat, so you want to use a relatively thick pan and allow it to preheat for long enough that there are no hot or cool spots. I let my pan preheat over medium heat for a few minutes, pumping it up to high just before I add the meat.
Rule 3: Smash early and smash firmly
Form anywhere from 2 to 5 ounces of meat into a puck about 2 inches high, season liberally with salt and pepper, place it in the preheated skillet, and smash it with the spatula, using a second spatula to add pressure if necessary. Then cook, without moving it, until a deep-brown crust develops. This'll take about a minute and a half.
Rule 4: Leave no crust behind
The whole goal of smashing is to develop a nice browned crust, so it's important that you scrape it all up intact when you flip the burger. Once again, a sturdy metal spatula is your friend. I find that turning the spatula upside down to help scrape the crust off is pretty effective. If your crust is properly developed and your burger properly smashed, it should spend very little time on its second side-just enough to finish cooking through and to allow the cheese (if added) to melt, 30 seconds or so. And, well, that's it. So simple, so fast, so freaking delicious. The great thing about smashing burgers is that it's so efficient at developing good flavor that even using store-bought ground beef (gasp!) will result in a darn tasty burger. Smashing is my go-to method when the mood for a burger strikes and I don't feel like lugging out the grinder.
Combine all ingredients.
Prepare burger bun by laying toppings on the bottom bun. Have it nearby and ready for when your burger is cooked.2.
Preheat a large stainless steel sauté pan or skillet over high heat for 2 minutes. Place balls of beef in the pan, and smash down with a stiff metal spatula, using a second spatula to add pressure. Smashed patties should be slightly wider than the burger bun.3.
Season generously with salt and pepper and allow to cook until well-browned and top is beginning to turn pale pink/gray in spots, about 45 seconds to 1 minute. Using a bench scraper or the back side of a stiff metal spatula, carefully scrape burger patties from pan, making sure to get all of the browned bits.4.
Flip patties and immediately place a slice of cheese over one patty and stack the second directly on top. Immediately remove from pan and transfer to waiting burger bun. Serve.
Note: these burgers cook very fast, so it's best to make them one at a time. If making multiple burgers, keep them warm under a tent of foil while preparing subsequent burgers.