[a_gentle_autist]

It's why New York Pizza is so good, it's the minerals in the water.

[zwieback]

I'd never heard of that and it's remotely plausible but apparently debunked:

http://slice.seriouseats.com/archives/2010/01/does-nyc-water...

[yzzxy]

This is generally understood to be debunked, but I believe the oven wall particulate theory is still possible.