At the turn of the 20th century, American bartenders handed out salty caviar for free so customers would buy more beer. This episode looks at how sturgeon roe went from peasant food and cheap bar snack to one of the most expensive foods on Earth, starting with the strict definition that limits true caviar to sturgeon and the Persian roots of the word.

We cover medieval Russians eating their roe hot, fermented, and spiced, the North American caviar gold rush on the Delaware and Columbia rivers, and the overfishing, poaching, and pollution that pushed sturgeon toward collapse. Then we look at the 2005 U.S. beluga ban, the CITES embargo, the rise of aquaculture led by China and Italy, no-kill harvesting, the $34,000-per-kilo Almas caviar, and vegan versions made from seaweed alginate.

• Why food authorities say salmon roe and lumpfish eggs are substitutes, not true caviar
• How slow-maturing sturgeon were wiped out by the caviar gold rush in American rivers
• How the fall of the Soviet Union, poaching, and pollution drove the Caspian collapse and global bans
• How China, Italy, and farms in unlikely places now produce caviar in recirculating aquaculture systems
• How ultrasound, massage-based no-kill harvesting, and spherification are changing caviar