What’s so great about tea? The surefooted William Cobbett saw nothing in tea beyond idleness and ruin; he described its effects in the 1820s as similar to dependency on foreign oil. Thousands of tons of dried leaf were being shipped around the world; governments grew fat on taxing it, smugglers were lured into criminality to supply it, housewives dissipated their looks and time to produce it, men were enfeebled by sipping it. One bloated monopoly, the East India Company, sponsored a trade in illegal drugs, corrupted governments at home and abroad, fought wars, and swallowed empires to keep it coming. The tea tax – reduced almost to nothingness – led to the American War of Independence, via the Boston Tea Party; Oliver Wendell Holmes’s ballad reported that: ‘The waters in the rebel bay / Have kept the tea-leaf savor; / Our old North-Enders in their spray / Still taste a Hyson flavour…’, hyson being the fanciest green tea of the time, as bohea was the cheapest black tea.

Tea really was the first global bulk commodity, and Cobbett was undoubtedly right to make the same sort of fuss over it that campaigners now make about SUVs or illegal diamonds. In his day the British drank around 30 million pounds of it a year. Later in the century, the