UKIAH, CA - JUNE 02:  A tall In-N-Out Burger sign can be seen from nearby Highway 101 as viewed on June 2, 2021, in Ukiah, California. Mendocino County, known for its wines, weed, hippies, laid-back lifestyle, and current drought, seems to be getting a population makeover as people who work remotely have moved to the region during the pandemic.  (Photo by George Rose/Getty Images)
Food - Drink
What Is A Mustard Burger At In-N-Out?
By ERICA MARTINEZ
A tray with an In-N-Out burger and fries next to a cup of soda
In-N-Out Burger is a wildly popular Southern California-based restaurant chain known for its juicy burgers, fresh-cut french fries, and superb milkshakes. Though the standard In-N-Out menu is rather simple, customers in the know are familiar with its "secret menu," which includes a special item called a mustard burger.
Several cheeseburgers from fast food chain In-N-Out
Nothing on In-N-Out's standard menu comes with mustard, so fans of this condiment need to request a mustard-grilled burger to get their fix. This sandwich is made by putting a beef patty on the griddle, then spreading mustard on top before flipping it so that it can seep in and imbue the browned meat with tangy flavor.
Open glass jar of mustard surrounded by mustard seeds
These mustard-grilled burgers also typically come with pickles, providing an extra sour kick and crunch. Another way to get a mustard-grilled patty is to order your burger in the notorious “animal style,” which comes with a mustard patty, pickles, grilled onions, and extra Thousand Island-style signature sauce.