The tale of Arthur Guinness, the firm's founder, is so familiar in Ireland that some schoolchildren can probably recite it from memory. Born in Celbridge, County Kildare in 1725, where his father worked as the steward to Archbishop Price of Cashel and brewed the estate's beer, he inherited two hundred pounds sterling on the archbishop's death and invested it in a brewery in nearby Leixlip, also in Kildare, operating it with his brother Richard. Three years later, he moved to Dublin and signed a nine-thousand-year lease on a defunct brewery at St. James's Gate for forty- five pounds per annum — a lease that's still in effect. The three-acre property included draft horses, a hayloft, and plenty of rats.

Though the location was excellent, allowing Guinness to transport kegs down the river on barges, he soon realized how difficult it would be to crack the city's market. The excise laws gave the English a leg up on the Irish, who were also obliged to buy their hops only from colonial suppliers at an inflated price, so beer imported from En gland cost the publicans much less. Only when "Uncle Arthur" decided to stop brewing ale in 1779 and concentrate on porter did his luck begin to change.

The credit for inventing porter ordinarily goes to Ralph Harwood of the Bell Brew house in Shoreditch, who developed it around 1722. Before that, England's best-selling beer was threethread, possibly a blend of pale ale, new brown ale, and stale brown ale. A publican did the mixing, but Harwood's Entire, a bitter, dark-brown beer, required no fuss and came in a single cask ideal for export. It got its name from the men who "ported" goods at such London markets as Covent Garden and Smithfield. They had adopted the brew as their own, and swallowed it with the gusto of dockers. Guinness's version, officially ruby-colored, was darker, richer, and more full-bodied than the original — a "stouter" porter, later simply stout. Its secret ingredient was a special strain of yeast whose clone is still around, supposedly kept under lock and key in the Directors' Safe at James's Gate.

Arthur Guinness, though a kind employer, could not be called politically progressive. When he opposed the Society of United Irishmen, a group dedicated to bridging the religious divide, reforming parliament, and ending England's dominion, his stout was pilloried as "Black Protestant Porter." In fact, the company was slow to hire Catholics and instead put teetotalers at the top of its list, because they were so dependable. Guinness's attitude toward its employees has always been patriarchal, and it isn't unusual for three or four generations of a family to have worked there. Boys in search of a job used to sit for an aptitude test in their early teens, and if they had a relative with the firm, they received a gold star on their exam that granted them preferential treatment. For the most part, they ran errands, but one boy was assigned the task of feeding raw fish to the cats that killed the rats. They got no free stout, of course, but adults did, still two pints a day at stations around the plant into the 1970s.

The plant covers fifty-five acres at St. James's Gate. The Guinness Store house, a sort of museum with a plentifully stocked, logo-heavy gift shop, is Ireland's leading tourist attraction, having surpassed the Book of Kells. If you take the self- guided tour, you'll learn that the word "beer" derives from the Anglo-Saxon for barley, a cereal that grows handily in the acidic soil of the Republic. Guinness buys about ninety thousand tons a year, or two thirds of the country's production. Hops come from abroad, with the most desirable found south of the equator. The water isn't drawn from the Liffey, although a few drinkers believe that it is, just as they subscribe to a hoary legend about a brewery worker who once drowned in a vat and lent the stout a remarkably delicious flavor as he decomposed. Streams in the mountains of Kildare are the actual source, and the soft water has a low mineral content, with hints of calcium and magnesium sulfate.

Do you care that Robert Louis Stevenson had some Guinness sent to him when he was writing Treasure Island in Samoa? Or that Guinness Foreign Export in bottles, almost twice as strong as keg stout, is considered an aid to sexual potency in Africa and the Caribbean? Maybe, maybe not. But you're sure to be astonished by the sheer thrust of the company's marketing efforts when your tour concludes at the glass-fronted Gravity Bar, seven floors above the city. The bar, closed to the public, gives you a magnificent 360-degree view, and while you savor your single complimentary pint — you can't buy a second, so don't bother to try — you'll marvel at how the firm has made James Joyce part of the team by stenciling quotes from his books on the windows, just as it features a harp, the national symbol, on its glassware and cans. Guinness is Ireland, the branding suggests, and it forges a bond so absolute that you'll feel unpatriotic if you don't finish your jar.

Excerpted from A Pint of Plain by Bill Barich. Copyright © 2009 Walker & Company. Excerpted by permission. All rights reserved.