Like all rational people, I eat a lot of grilled cheese sandwiches. My devotion has deep roots. Few childhood memories are as clear as when I tasted a bite of my mom’s grilled cheese and tomato sandwich on buttery whole wheat toast at a New Jersey diner circa age nine and thought, “This is the height of sophistication.” In my 20s, I was lucky enough to travel to Paris on a shoestring budget and sustained myself on a steady diet of croque monsieur, France's bechamel-bathed answer to grilled ham and cheese. Nowadays, I make grilled cheese sandwiches for lunch or even breakfast—it makes more sense the longer you think about it—more frequently than I care to admit in writing.

Repetition is key to mastery, at least according to personal trainers on the internet, and I’d like to think I’ve fine-tuned my grilled cheese technique over the years. For me, the success of the sandwich relies on two primary components: evenly melted cheese plus buttery bread that’s crisp enough to maintain its structural integrity but not burnt. My preferred add-ins include kimchi, salted tomato slices or grainy mustard, but all are secondary to the successful marriage of toast and cheese. It’s a reciprocal relationship. If you undercook the bread, the sandwich is soggy and the cheese might not melt properly. If you overdo it, then all you taste is char.

That’s why the secret to perfect grilled cheese is mayonnaise. Hear me out: If you butter only the inside of your bread and spread a thin schmear of mayo on the exterior of the sandwich, you create the ideal conditions for the bread to toast, cheese to melt and butter to shine. The mayonnaise doesn’t actually provide flavor — if you’re a mayo hater, you won’t even taste it, I promise — but instead encourages ideal browning and melting.

Why It Works

It’s culinary science, explains Michael D. Makuch, the department chair of the College of Food Innovation and Technology at Johnson & Wales in Providence, Rhode Island. Mayonnaise has a smoke point of approximately 450 degrees F, whereas butter’s is anywhere from 300 to 350 degrees F. “When your fat reaches its smoke point, that's when you start to generate some of the flavor compounds that give off a bitter, burnt-tasting flavor.” In other words, the fat in mayonnaise is less likely to burn in your hot pan, giving the cheese more time to reach its melty, oozy potential.

“Using mayonnaise also helps create that Maillard reaction,” says Makuch. The Maillard reaction is the tasty browning that occurs on food when complex carbohydrates and protein—in the case of grilled cheese with mayonnaise, that’s the sliced bread plus the eggs in mayo—are heated to 280 to 330 degrees F. “It generates a lot of savory flavors in food... Any time you cook a steak or any protein on the grill, and it gets that nice sear with lots of flavor, that’s the Maillard reaction,” he adds.

Chemistry aside, there are practical reasons to try making grilled cheese with mayonnaise. Unlike cold butter, mayonnaise is spreadable straight from the fridge, “so it’s going to make prep a little easier,” says Makuch. It also retains moisture that keeps the toast from drying out.

How to Make Grilled Cheese With Mayonnaise

Butter one side of two slices of bread, then put your preferred cheese between them, buttered-sides in, to add flavor to your finished product Spread a thin layer of mayonnaise on the outside of each slice. Heat a nonstick or heavily seasoned pan over medium-low heat. Put the sandwich, mayo side down, in the buttered pan for about 3 to 4 minutes, then flip and repeat.

You can scale this process up to make multiple sandwiches simultaneously, or enjoy the platonic ideal of grilled cheese alone, standing at the counter, basking in your own ingenuity. “The grilled cheese is more complex than people give it credit for,” says Makuch. “And a good grilled cheese is second to none.”

Grilled Cheese Recipes

Want to give this technique a try? Here are a few of our favorite grilled cheese recipes.

The Perfect Grilled Cheese

The classic and simple grilled cheese sandwich is the perfect canvas for experimentation and can be reimagined multiple ways.

Kielbasa Grilled Cheese

Hearty kielbasa, shredded coleslaw mix, rye bread and thinly sliced jalapenos give this grilled cheese worlds of flavor.

Grilled Cheese Sandwiches With Bacon

The only thing better than a Cheddar-and-Monterey Jack grilled cheese sandwich? One made with crisp slices of bacon.

Kimchi Grilled Cheese Sandwich

This classic, comforting grilled cheese gets its kick from the spicy-sour crunch of kimchi.

Cheddar and Apple Grilled Cheese Sandwiches

Bite into crisp, autumnal flavors with this classic combination of tart apples and savory Cheddar.

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