This is a very well-written and readable survey of the Coffee House, particularly focused on London but occasionally diverting elsewhere. Ellis' story begins in Constantinople in the sixteenth century, noting that coffee arrived there from the Middle East, probably tracing a route through Syria and Yemen, from its ultimate origins in Ethiopia. Merchants and travellers observed the rituals and sociability of the coffee-house, and took the beans and the idea back to London.
A great part of the book focuses on London in the time of the Commonwealth and the Restoration, when the coffee-house served as a meeting and debating place particularly for more radical opinions. For this alone, it's well worth considering the book as a complementary narrative to Fly By Night. So worried was Charles II about rumours of sedition that he tried to have them banned, but his plans were prevented by uneasy compromises somewhat reminiscent of the curtailment of civil liberties in current times and the more recent Regulation of Investigatory Powers Act (essentially, coffee-house owners taking responsibility of reporting any suspicious activity to the authorities).
Away from politics, Ellis describes the other functions served by the coffee-house: a meeting place for merchants, becoming a trading place (the precursor to the Stock Exchange); a place for scientific demonstration and debate, away from closed academic institutions; a place for self-improvement through philosophical sociability (the precursor to Gentlemen's Clubs). He also talks briefly about the spread of coffee through Europe and into North America.
The coffee-house in London declines towards the nineteenth century as a result of the rise of the East India company and the popularisation of tea, but is reborn after World War Two in a somewhat different guise, as the Italian espresso technology spreads, again gaining a radical market in 1950s and 60s culture. Ellis wraps up with an interesting essay on the Starbucks phenomenon, critically observing that whilst the marketing message is the very traditional line on coffee and virtue, this is somewhat at odds with the reality of its market position in globalisation and popular culture. Pertinent to the central character in the story, he also observes that all the varieties of drink available in Starbucks and other chains contain fundamentally identical coffee - it is in the method and preparation of additives such as milk where these products differ.
If I had to pick fault with the book, it is its use of endnotes. These are copious but serve only to cite sources, a fair and consistent policy, but there are occasions when one might have hoped for a little further explanation of a point.