In the revealing new book “The Ins-N-Outs of In-N-Out Burger: The Inside Story of California’s First Drive-Through and How it Became a Beloved Cultural Icon,” the granddaughter of the fast-food chain’s founder uncovers several little-known facts about the iconic In-N-Out Burger.

The book delves into the origins of the famous “Animal Style” burger, which was inspired by teenagers hanging out in the restaurant’s parking lot, requesting burgers made in a special way similar to how the managers prepared them for themselves. This style includes a unique combination of grilled onions, extra spread, and a mustard grilled patty.

The book also explores the chain’s not-so-secret menu, which might still surprise regular diners.

This includes the “Animal Style” burger, the bun-less “Flying Dutchman,” named after the founder’s racing name, and the “Protein Style” burger wrapped in lettuce.

There’s also the “Tomato Wrap,” similar to Protein Style but with tomato slices instead of lettuce, and the vegetarian-friendly “Veggie Burger,” originally known as a “Wish Burger.”

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Other notable menu items include the “Grilled Cheese,” the “Double Meat” burger, and the more indulgent “3×3” and “4×4” burgers. While there are rumors of even larger combinations, former employees confirm that 4×4 is the maximum officially offered.

Customers at In-N-Out can also customize their orders in various ways, like requesting non-toasted or extra-toasted buns, adding chopped chilies, or asking for burgers to be cut in halves or quarters.

Unusual requests include the option for “cold” cheese, not melted on the burger, and the popular choice for dog owners: a salt-free meat patty.

The beverage selection at In-N-Out includes unique options like the Neapolitan shake, blending chocolate, vanilla, and strawberry, and a root beer float that combines a vanilla shake with root beer.

For fries, customers can ask for them “well done” for extra crispiness, “light” for less cooking, or in styles like “cheese fries” and “Animal Style Fries,” which include cheese, spread, and grilled onions.

Filled with company history, drama, and detailed descriptions of its menu offerings, the book not only informs but also entices readers with the rich legacy of In-N-Out Burger.

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