Save The Deli: In Search of Perfect Pastrami, Crusty Rye, and the Heart of Jewish Delicatessen By David Sax Houghton Mifflin Harcourt 366 pages $24 Lenny Bruce's famous riff on Jewish versus non-Jewish includes the much quoted line, "Dig... if you live in New York or any other big city you are Jewish. It doesn't matter if you are Catholic. If you live in New York, you are Jewish. If you live in Butte, Montana, you are going to be goyish even if you are Jewish." In David Sax's eyes, while all deli - even nonkosher deli served in small towns such as Butte, Montana - is firmly Jewish, meat served on anything other than rye is not only not Jewish, but also sacrilegious. To wit: A Reuben sandwich (hot corned beef, sauerkraut and Russian dressing on grilled dark rye with a layer of melted Swiss cheese) is Jewish. Mayonnaise, definitely not Jewish. As for white bread, don't even go there. In Save the Deli, Sax voyages "in search of perfect pastrami, crusty rye and the heart of Jewish delicatessen." His travels take him to the deli heartlands of America; through the US deli wilderness (pretty much anywhere that is not New York and Los Angeles); on a nostalgic gastronomic trip to his native Canada and to the deli diaspora (Western Europe). He culminates his culinary expedition in Poland, where the issue of what makes Jewish food "Jewish" is really tested. Interspersed with vignettes of the delis and the deli men - a breed unto themselves - he visits on his tour, Sax discusses the origins of deli from its heyday to its fall from grace. Along the way, he provides a generous helping of Jewish history, a helpful serving of Yiddish and a huge dollop of humor. The story of deli can be summed up as follows: The Jews came, they ate, they left. From New York to San Francisco, and from London to Paris, the tale is almost identical. Either the inhabitants of the immigrant neighborhoods did well, moved up and moved out - their neighborhoods taken over by other newly arrived immigrant groups - or they stayed and got old. Either way, it was bad news for the deli. Helping to ring its own death knell, Sax readily admits that deli is not a cuisine that easily attracts new devotees to replace the veteran noshers who grew up with schmaltz and ptcha running, quite literally, through their veins. (Sax proudly cites as one of these old timers, his grandfather, "Poppa" Sam Sax, to whom the book is dedicated and who died after ingesting speck - paprika-dusted, twice-smoked slices of pickled fat from a brisket.) The younger generation, Sax reasons, sees deli food as part of the old way of life, a ghetto food, and more readily identifies with the fare of Israel. "While deli is the food of nostalgia, Israeli cuisine is the food of pride. Young Jews today know the past of Jewish Europe mainly from the Holocaust. But when they eat falafel, they are engaging in a solidarity of sorts with their brethren in the Middle East. They are indulging not in the memory of a lost time and place, but of a proud, courageous, sexy nation." In many cases, it is non-Jewish fressers filling the deli vacuum. In London, for example, Mitchell Tillman, the owner of Harry Morgan's, a deli located in St. John's Wood, sees a big part of his weekly business come after Friday services at the London Central Mosque. Tillman's meat, by the way, is not kosher but it is halal. (And, according to Bruce, that would make these particular Muslims Jewish! Dig?) But it's not just the deli clientele that has changed. Often the owners are not Jewish and the same is usually true of the workers making and serving the food. "Mexican and Latin American workers have silently become the new Jewish mothers. Delicatessen fans nationwide owe them an overdue gracias," says Sax. With its disparate parts: travelogue, food tour, Yiddish lesson and history book, Save the Deli is like a true deli sandwich. It is composed of simple but tasty ingredients and it is easy to digest. However, it definitely contains a little bit of gristle. Those who believe Jewish food should be kosher might take exception to the idea that a deli serving bacon or meat and cheese can be "Jewish." Such readers might also wince at Sax's confusion over what makes a deli either glatt kosher or kosher. While his misunderstanding does not detract from the flavor of the book, it could bring about heartburn in certain readers (as well as some deli owners). Whether deli has to be kosher to be Jewish or whether a steaming hot plate of chicken soup outweighs all other considerations, Sax's book is a gastronomic romp through a food tradition that mostly lives in the Jewish past. The once ubiquitous dishes, such as gribenes, kishke and the infamous and deadly speck, are now nothing more than flavorsome footnotes in the culinary landscape. With devotees like Sax keeping them on the menu, these traditional dishes will be enjoyed by future generations. And just remember, you don't have to be Jewish to love deli.