Bagels outside New York generally taste like poor imitations of the real thing. And sometimes that gets chalked up to some magical quality of New York City tap water.
Not so, the American Chemical Society says. The secret, instead, is in the technique.
Making a traditional New York bagel requires two steps that are sometimes skipped: you have to keep the bagels somewhere cool for a while to deepen the flavors before baking, and you have to boil them before you bake them. In other words, you don't need New York tap water — you just need a good recipe. (I like this one.)
There's been a spate of inquiries into bagel science lately: Cooks Illustrated wrote in its latest issue that "the vast majority" of tasters couldn't taste the difference between bagels made with water from New York and bagels made with water from Brookline, Massachusetts. Coincidentally, over the weekend I tried it myself with tap water from New York and DC, and found the same result.
(For the record, Montreal bagels are also very good, and you have to boil them too.)