Brewing water is the single largest ingredient by volume in any beer recipe and it is the foundation for many different styles of beer. By now we’ve all read or heard about the relationship of the water in a region to a particular style of beer. For instance Dublin’s hard water makes a great tasting stout, Burton’s gypsum rich water is great for making pale ale and Pilsen’s soft water makes a really good pale lager.
The brewer should also understand that all regions experience seasonal changes in their water properties and to some extent yearly changes too. One notable case for example was the 2013 Sonoma County drought that prompted the Lagunitas Brewing Company to inform their customers that the river water supply that gives their beer it’s unique signature taste may have to be replaced with reverse osmosis filtered water from another source. That’s a clear example of how much brewers rely on a consistent supply of water in order to eliminate variations that change the taste and quality of their finished beer.
There are basically two approaches to maintaining brewing water consistency year after year and from season to season. If you have the resources needed to check your water source for alkalinity, pH, salt and mineral levels and are able to adjust them as needed to match a specific brewing water profile consider yourself among the most fortunate of home brewers. Since the source water properties can vary greatly over time the adjustments needed to bring them in line with a specific water profile will need to be adjusted too in order to compensate for these changes. Or instead you could use a consistent water source like distilled or reverse osmosis water and adjust the pH levels up with baking soda or down with lactic acid until they are in range of your targeted brewing water profile.