One of America’s favorite fast-casual restaurants, Texas Roadhouse, just revealed some of the secret ingredients that make their special BBQ sauce, well, special.

Mashed reached out to Texas Roadhouse’s corporate offices and boldly asked them what’s in the sauce that makes people coming back for more.

The chain’s Megan Pence answered the phone and the questions, kind of. She walked the line — like Johnny Cash once did — and told us more than we already knew, but less than what we’d need to know to make a copycat recipe.

“Our barbecue [sauce] could be classified as a St. Louis-style sauce: Sweet, smoky, and some zesty spices on the finish,” she says.

A BBQ connoisseur would be able to tell you a lot about the flavor profile of Texas Roadhouse’s sauce just based off of that information. St. Louis BBQ sauces tend to include yellow mustard, apple cider vinegar and spices like garlic powder and cayenne.

Here’s the kicker, though: Pence swears the Texas Roadhouse BBQ sauce cannot be duplicated.

“Our BBQ sauce was developed by our Founder, Kent Taylor, and our original Chef, Jim Broyles. They tested several versions at our first location before landing on our current formulation,” she says.

While a lot of major chain restaurants are bottling up their special sauces to sell at grocery stores, it sounds like we won’t be seeing that from Texas Roadhouse anytime soon, because they would have to list the ingredients.