The Secret Ingredient to Fast Food-Style Smash Burgers (Psst—You Already Have It)

Take a tip from In-N-Out and pull out this condiment before you cook.

<p>Dotdash Meredith Food Studios</p>

Dotdash Meredith Food Studios

Summer is here and that means it's officially grilling season! But the burger on everyone's lips this year seems to be the smash burger. From the viral Smash Burger Tacos to the newly-trending, onion-laden Oklahoma Burger, smash burgers are all over social media. It could be due to the rise in popularity of griddles, or the desire to recreate our fast food favorites at home. Or, it could just be that they're pretty dang delicious.

With juicy centers and those irresistible lacy, crispy edges, there's so much to love about smash burgers. Our staff is particularly enamored with this style of burger, always on the hunt for tools, tips, and techniques to make them even better. Well, I just learned the greatest tip I have ever learned for fast food-style smash burgers, and the best part is, I can almost guarantee you have everything you need to make them right now. And it all starts at In-N-Out.

In-N-Out's Secret to Fast Food-Style Smash Burgers

When it comes to recreating a fast food experience at home, sometimes the best place to start is by going straight to the source (they do say imitation is the sincerest form of flattery!). Well, my favorite fast food burger is In-N-Out, the California-based chain with a cult following. If you've ever heard of In-N-Out, you'll know that the chain is best known for its Animal-Style burgers and fries, an off-menu, secret-but-not-so-secret line of offerings.

What differentiates the Animal-Style Burger from all others? There is a good ol' fashioned secret sauce (or spread, at In-N-Out), aka, a variation of Thousand Island Dressing. But more than that, there are grilled onions, and—in fine print on the In-N-Out website—the fact that it features a "mustard-cooked beef patty."

That's right. The one ingredient secret to the best dang burgers is just yellow mustard. But, the real secret lies in when—and how—you add it to the burgers.

How to Make Animal-Style Burgers at Home

In-N-Out places its burger patties on the flat-top griddle then spreads about a teaspoon or two of yellow mustard on the uncooked side just before flipping. The mustard caramelizes on the griddle, softening that piquant quality mustard can have, and creating an even crispier crust as the burger patties get smashed. It is truly a thing of beauty.

The sweet, caramelized onions and secret "spread" both bring a little sweetness to the burger, while the mustard-griddled patty imbues a deep flavor with just a little mustardy kick on the back end. Together—alongside crisp lettuce and pickles, and a plush bun—they create a perfectly harmonious burger. It's not hard to see why the chain has the following it has.

If you don't live by an In-N-Out, the good news is that this trick is easy to steal for your at-home adventures in smash burger perfecting. All you really need is yellow mustard, though I would argue that caramelized onions are an integral part of the equation, as well. The even better news is that we have a Copycat Animal-Style Burger recipe on Allrecipes, so you can make a replica right in your very own kitchen. Happy smashing!

<p>Allrecipes Magazine</p>

Allrecipes Magazine

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