In “Why New York Has the Best Bagels“, the folks at Reactions explain that it’s not just the water, but a specific combination of minerals in the water, a fermenting process called “proofing”, and then boiling the bagels before baking that make New York City bagels the best in the world.
For a long time many insisted it was the one ingredient that comes from the tap. The “wahta” as they say does play a minor role in how New York bagels turn out. …good bagel bakeries according to the chef let those trays of bagels sit in a cooler for a couple of days, a process called proofing. This allows the yeast time to slowly ferment. …At Murray’s the bagels come out of the cooler and make one more crucial stop before the oven – the kettle. Boiling the bagels from anywhere from thirty seconds to three minutes pre-gelatinizes the starch. This locks the liquid into the startch, setting up the perfect bagel-y texture.