Costco's famous $5 rotisserie chicken has a shelf life of just 2 hours, according to super fans who have visited over 200 stores

• David and Susan Schwartz are self-described Costco superfans. 
• The couple, who wrote an entire book about the retailer, have visited over 200 Costco stores. 
• During their research, they made a discovery about Costco's beloved $5 rotisserie chicken. 

Even if you aren't familiar with Costco, you've probably heard a thing or two about its signature rotisserie chicken.

Sold for just $4.99, the birds have amassed such a fanbase among Costco regulars that the retailer sells millions a year. Shoppers are even known to race to grab a chicken, beloved for their flavor, tenderness, and size.

But the most surprising thing about the rotisserie chicken is how little time it actually spends on the shelf, according to a couple who spent seven years visiting over 200 Costco stores around the world.

David and Susan Schwartz, authors of "The Joy of Costco: A Treasure Hunt from A to Z," told Insider they spent seven years researching Costco, which led them to circumnavigate the globe a total of three times in their pursuit to find out as much as they possibly could about their favorite wholesaler.

Along their travels, they made a discovery: Costco's rotisserie chickens only spend approximately two hours on the shelf of any warehouse.

"They time stamp the rotisserie chicken so that it's only on the shelf for two hours because it doesn't taste as good after two hours," David said.

When time runs out, the couple says employees remove any remaining chicken from the shelf and repurpose the meat in other dishes, such as soups and salads.

Costco did not respond to Insider's request to confirm David and Susan's discovery.

According to the authors, time-stamping Costco's signature rotisserie chicken is just one example of why they believe the wholesaler is a cut above other retailers.

"They do the right thing when no one's looking," Susan said. "They just are decent. And that's just a great thing."

Costco and its famed chicken aren't without controversy.

In 2019, the chain spent upwards of $450 million building a chicken-processing plant in Nebraska, CNN Business reported, in an effort to provide two million chickens per week for Costco and help keep the rotisserie chicken priced at $5. In 2022, however, a lawsuit was brought in Seattle alleging "Costco illegally neglects and abandons its chickens." The suit is ongoing and Costco did not respond to Insider's requests for further comment.

The amount of time the chicken spends on the shelf isn't the only fact David and Susan learned in their travels. In their book, the pair break down some of the local delicacies found in Costco stores around the world, including a rotisserie chicken sold with the head on in Taiwan.

You can read more about David and Susan Schwartz and their book, "The Joy of Costco: A Treasure Hunt from A to Z," here.