There was a question on the SF boad asking if any restaurant imported NY tap water to make bagels or pizza. This one article says about why pizza dough is better in NY ...
"After meeting with several chefs, the consensus is the water. The mineral content of New York water, which comes from the Catskills has a unique effect on the rising and the flavor to the dough."
Until that quote I thought the issue was silly, but maybe there's a there, there. Could that be why the bagels are better in NY, the sourdough better in SF, etc ... the composition of the local water someone impacts the results?
Would using bottled water give different results based on the brand?