The grapefruit looks like the most predictable item on the breakfast table, but its history is anything but mundane. This deep dive traces Citrus paradisi from its accidental origin as a cross between the sweet orange and the pomelo in 18th century Barbados, through its first written record in 1750 by Welsh clergyman Griffith Hughes, who called it the forbidden fruit, to the confusing name coined around 1814 by John Lunen. We follow Count Odette Philippe bringing the fruit to Florida in 1823 and Kimball Chase Atwood industrializing it with the largest grapefruit grove in the world.

From there the story gets stranger. A pink mutation in 1906 and a red one in 1929 gave the world Ruby Red, but the color faded as the season progressed, so mid-century scientists turned to atomic gardening, bombarding bud sticks with thermal neutrons to create Rio Red and Star Ruby. We also cover Cuban grapefruit steak from the special period, the chemistry of citric acid and grapefruit mercaptan, and the serious pharmacology of furanocoumarins like bergamotin, which disable the CYP3A4 enzyme and can turn a single seven ounce glass of juice into a medical hazard.

• How the sweet orange and pomelo accidentally hybridized in the Caribbean and why the fruit was named after grapes
• The Florida boom under Atwood and the discovery and patenting of the Ruby Red variety, later named the state fruit of Texas in 1993
• Why breeders used thermal neutron radiation to lock in red color and produce Rio Red and Star Ruby
• Bistec de Toronja: how Cubans fried grapefruit pith as a meat substitute during the 1990s crisis
• Suicide inhibition of CYP3A4, prodrugs, rhabdomyolysis risk, and why the grapefruit warning on prescription bottles is not optional