H&H Bagels, the most famous of New York’s many legendary bagel establishments, will close its doors on Sunday after 39 years in business. Some enthusiasts credit the city’s unique water chemistry with making Gotham’s bagels seemingly irreproducible in other locales. Does water chemistry really explain why it’s difficult to get a good bagel outside of New York?

No. Water chemistry influences baking, and New York’s somewhat unique water probably plays a minor role in making tender and chewy bagels. New York City has very soft water—meaning it has low concentrations of calcium and magnesium. The concentration of calcium carbonate, for example, is 19 milligrams per liter (PDF) in New York water. By comparison, it’s 55 in San Francisco (PDF), 136 in Washington, D.C. (PDF), 149 in Chicago (PDF), and more than 200 in parts of Los Angeles (PDF). Hardness enhances the strength of gluten, the protein-containing compound that toughens baked goods. So differences in water hardness are a convenient explanation for the tooth-rattling bagels you get in many cities.

But New York’s bagel supremacy has far more to do with production practices than water quality. Gotham’s bagelries typically poach the bagels prior to baking them—the bagels spend a few minutes simmering in a pot of water before entering the dry heat of an oven. That pre-gelatinization process produces a chewy interior, and slightly changes the flavor of the finished product.

Many bagel makers skip the poaching step, because the boiling equipment is expensive and takes up space in the kitchen. Instead, they brush their bagels with a little water and baking soda in the style of soft pretzels, then blast them with steam once they’re in the oven. You can usually identify these impostors by checking out their undersides, since steam can’t get to the bottom of a bagel when it’s already in the oven. If the bottom is significantly darker and harder than the rest of the surface, you’re eating a roll with a hole, not a bagel.

Similarly, whereas New York’s venerable bagel establishments tend to ferment their dough slowly in wooden containers, fly-by-night operations abbreviate this process. The longer method employed by traditionalists allows the yeast to produce more than 50 flavor compounds. These chemicals not only permeate the dough; they also seep into the pores of the wood over the years, giving the final product a flavor that can be hard to replicate in newer bakeries. (Wooden bowls are, however, not preferred by government health departments, and old-school bagel shops tend to perform poorly in inspections. The Explainer confirmed this by checking the report for his favorite bagel shop. Not good.)

While water chemistry plays a bit part in bagels, it is enormously important in brewing, and some beer styles are nearly impossible to replicate outside of their native watershed. Pilsener comes from the Czech city of Pilsen, where the water’s mineral concentration is extremely low. Brewers wishing to re-create the crisp, clean pilsener style have to start with distilled water and add tiny amounts of minerals. By contrast, the English city of Burton-upon-Trent, which invented the hoppy India Pale Ale now popular among American brewers, has very hard water. The concentration of calcium in Burton is about 35 times that of Pilsen. The concentration of sulfate, which accentuates the bite of hops, is more than 200 times higher.

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Explainer thanks Richard J. Coppedge Jr. of the Culinary Institute of America, Kirk O’Donnell and Debi Rogers of the American Institute of Baking, and Susan Reid of King Arthur Flour.