One folk tale has it that Christians in medieval Prussia insisted that Jews should not be allowed to bake bread because of its connection with Jesus (via the communion wafer). To get round the prohibition, Jewish bakers boiled the dough and lightly toasted the result. When things calmed down, they boiled and baked, and that's still what happens today. Its Jewish identity was confirmed in a regulation issued by the Jewish council of Krakow in 1610 which decreed that it form part of the celebrations marking a baby boy's circumcision.

By the 19th century, the bagel had spread into the everyday diet of the Polish poor, and when Polish Jews migrated westwards to escape persecution they took the bagel with them. The poor masses huddled in terrible conditions on the Lower East Side and baked their bagels in utterly squalid premises until minimal regulations were introduced, if lightly enforced.

Ms Balinska devotes an inordinately lengthy section to the history of the New York bakery unions' struggles, whose relevance to the subject matter is tenuous to say the least. Business deals are much more interesting to read about than strikes. The eventual triumph of the American bagel is largely due to the efforts of the Lender brothers, who turned a small family bakery in New Haven, Connecticut, into America's largest bagel business, ceaselessly marrying new technology, particularly freezing, with imaginative marketing: on one occasion, Murray Lender climbed on to a sceptical supermarket buyer's desk, dropped his trousers to display underpants bearing the slogan "Buy Bagels" and started chanting "Frozen bagels!" He got the order. The firm expanded inexorably; it is now owned by the giant private equity group Blackstone.

For many assimilated American Jews, bagel and lox (smoked salmon) for Sunday brunch was virtually their only connection to Jewish life, but better that than nothing at all, as Irving Howe once mused in their defence. History, for the bagel (in London beigel, closer to the Yiddish) marches on: there are 15 obwarzanek bakeries in Krakow and an American bagel bakery in Kazimierz, its old Jewish quarter. The bread of queens, and then the poor, is now truly middle class.