For thousands of years fermented foods - bread, wine, beer, pickles, sausage, cheese - have nourished humanity through dearth and famine, the founding of ancient kingdoms and the building of industrial cities. Fermentation, and its preserving effects, gave humans food security. Tiny microorganisms - bacteria, yeasts and mould - do the magic of turning cabbage into kimchi and grapes into wine. Yet fear of contaminants in the nineteenth and twentieth centuries led modern people away from home fermenting and towards mass-produced food. From the scientific drive to brew better beer to the cured meats of Iceland and the piquant, sometimes deadly ferments of Southeast Asia, this fascinating and often whimsical history is a celebration of the world's favourite fermented foods.