Ask For A 'Mustard Grilled' Burger At In-N-Out To Get The Real Deal Flavor

Many people will tell you that if you want a quick, mouthwatering burger, In-N-Out is the place to go. Indeed, a 2022 survey conducted by Market Force found that In-N-Out ranked as America's top hamburger joint in terms of customer loyalty. The chain's tiny menu includes three default burger options, as well as fries, drinks, and shakes. Of course, fans are familiar with the Not So Secret Menu, which allows guests to customize their sandwich in a number of different ways. One lesser-known option is to request a "mustard grilled" patty.

The burger patty will be placed on the griddle as normal, but right before it's flipped, the cook will squirt a little yellow mustard on the uncooked side. Once flipped, the mustard side will get smashed down and spread, seasoning the patty and transforming into a glorious crust that adds both color and flavor to the meat. The mustard flavor intensifies as it sizzles and is an excellent foil to the fattiness of the ground beef (and cheese, if you opt for it). From here, the burger gets topped with iceberg lettuce, tomato, white onion, and Thousand Island sauce.

One of the most popular options on the chain's Not So Secret Menu is ordering your burger Animal Style. This version comes with pickles, extra sauce, and grilled onions, and what many don't realize is that it also automatically includes mustard-grilled patties.

Although the menu at In-N-Out is small, it is refreshingly easy and quick to scan, compared to other fast food restaurants. And, though every customization may not be on display, there are several different ways to spruce up a burger here. If you'd rather have the mustard on your bun than on your patty, just ask for it. You can have ketchup added to your bun, too. There aren't a ton of extra toppings offered, but pickles and sport peppers are available; ask for "chopped chiles" for the latter.

The onions can come in a few different forms: Raw is standard, but requesting grilled onions will give you a generous amount of chopped, caramelized onions on your patty. You can also ask for a whole grilled onion, and a slice of onion will be griddled.

Protein Style burgers will come wrapped in crisp lettuce rather than a bun, and grilled cheeses are available, as well — just simple but memorable toasted, buttered buns and gooey, melted cheese. A Flying Dutchman is simply two patties with cheese in the middle (no bun or veggies), and you can ask this to be done Animal Style, as well.

Trying In-N-Out's mustard-grilling trick at home when you make your own hamburgers is incredibly simple. A little mustard will go a long way, so you won't need much more than a teaspoon per burger patty. This method is best for cooking burgers on a griddle or flat-top grill, where you can really press down on the meat patties to get a good sear. If you try to do this on a standard grill, the meat could come apart and fall right through the grates. You can even prepare these burgers in a cast-iron pan; just be sure it's nice and hot so you get that all-important caramelization on the mustard-coated meat.

Yellow mustard is the classic choice, and what In-N-Out uses for its mustard-grilled patties, but feel free to play around with flavors. Dijon, honey mustard, and truffle mustard might come as tasty surprises, especially if you'd rather make burgers out of ground turkey or chicken, which benefit from a little added flavor. Even veggie burgers will get an extra zing from a tangy mustard punch.