Ginger beer

, also known as ginger pop, was a favourite drink of the fourth and eighth incarnations of the Doctor. (TV: The Android Invasion, PROSE: Rip Tide)

The Fourth Doctor drank ginger pop after arriving on a facsimile of Earth. He offered some to Sarah Jane Smith, but she disliked it. Later, he offered the beverage to Sarah's android double, who drank it without question. This was one of the ways in which the Doctor was able to discern that this was a fake Sarah, and indeed a fake Earth. (TV: The Android Invasion)

The Tenth Doctor used ginger beer as an ingredient of an antidote for cyanide. (TV: The Unicorn and the Wasp)

William Shakespeare got the Fifth Doctor drunk on ginger beer-spiked drink and effectively stole the TARDIS as a consequence. The Doctor later explained that "ginger pop [had] a profoundly deleterious effect on Time Lord metabolism". (AUDIO: The Kingmaker)