The royal family’s drinking habits have long fascinated the general public—from the dry gin martinis Queen Elizabeth II favored even in the final years of her life to the occasional gin and tonic Prince William reportedly makes Kate Middleton after the children have gone off to bed. The Dutch spirit has long since conquered the palates of the British royal family. But according to Paul Burrell, Lady Diana’s former butler, gin flowed a little too freely at Buckingham Palace, sometimes even under the radar of protocol.

In his book The Royal Insider: My Life with the Queen, the King and Princess Diana, he reveals the liquid preferences—and creative strategies for enjoying them—deployed within the palace. “I quickly became familiar with the royal family’s ingenious methods of smuggling alcohol into their soirees,” Burrell writes (via The Sun). He recounts how, every evening, he was asked to empty a screw-top bottle of tonic water and fill it with gin, destined for the royal chambers.

He claims that gallons of gin were sold every week in this way. And the system was not lacking in imagination: some members of staff transported the precious beverage in electric kettles, supposedly containing water. A double-edged sword: the gin was sometimes brought to the boil by mistake…

While alcohol flowed with ease, other gustatory pleasures were strictly controlled. Grant Harrold, also a former court butler, previously revealed some closely guarded secrets about the royal eating habits. In an interview with L‘Express, he claims that certain products are simply forbidden—or at least kept to the bare minimum—in Buckingham’s kitchens including forms of seafood, garlic, and foie gras… The aim? To avoid poisoning, embarrassing smells during an official handshake, or simply to respect the personal convictions of certain family members.

It’s an amusing contrast when you consider that, as children, William and Harry were crazy about fast food. “Their guilty pleasure was the fast-food takeaways in the next village,” Harrold once told Marie Claire. The young princes even defied safety regulations to fetch their own burger or chicken nuggets. Even today, Prince William remains a fervent fan of fast food, particularly the South African spot Nando’s, a popular chain in the UK.

Like most other aspects of royal life, even the Windsor family’s gastronomical habits are sometimes subject to meticulous protocol—at no extra charge.

Originally published in Vanity Fair France