The range and variety of beer styles from around the world were in large part the products of the local water they were brewed with. The local water chemistry made some styles more suitable for brewing or the water enhanced beer flavor. Unfortunately, some brewers make the mistake of trying to use historic water profiles in their brewing without understanding what adjustments those historic brewers made to brew with their local water. This presentation will discuss water profiles from several historic brewing centers, discuss their historic importance to brewing, and their part in the development of local styles. The overall goal is to educate brewers about appropriate ions levels for brewing and avoiding the pitfalls of brewing with historic water profiles.