Changes
From BrewWiki
The principal ions are:
* '''Calcium (Ca)''' - Aids in mashing and yeast growth if used in moderation. Should be kept to the 80-100 ppm range for mashing and sparging. Ca is the major ion responsible for mash acidification. The process is calcium ions react with phosphates in malt creating calcium phosphate and hydrogen ions. An increase in Hydrogen ion concentration reduces pH and is "buffered'by the presence of Bicarbonates and carbonates therefore sufficient calcium ions need to be present to overcome the buffering to reduce pH to correct mash pH of 5.2 to 5.6
* '''Sulfate (SO4)''' - Accentuates hop bitterness, though overuse can result in unpleasant flavor/the form of Calcium Sulphate for adding calcium if the water is deficient in sulfate and is used to add sulfate "crispness" to hop bitterness.
* '''Sodium (Na)''' - Helps to accentuate sweetness of malt at levels below 100 ppm. Generally should be kept to a low to moderate level as high levels are associated with sour, salty tastes.
* '''Chloride (Cl)''' - Accentuated flavor of beer when kept below 100 ppm for light beers or a max of 300 ppm for dark beers. Can result in bleach or medicine flavor if raised too high.
German Brewers of old employed an acid rest to acidify the mash, as, due to insufficient calcium ions in the low mineral content water, the mash would not reach the desired pH. The acid rest allowed enzymatic phytase activity and in no small part bacterial activity and growth to acidify mash. The low mineral content water in Dublin was overcome by the addition of highly roasted acid malts and of course made beer quite dark!. Burton water that is high in calcium ions meant that an acid rest was not needed and a single infusion mash is all that was required. Malting technology in the past meant that a percentage of the kilned malt was burnt producing the acidity required such malt was also often poorly modified. Better technology lead to lighter kilned malts great for light lager, but required an acid rest in low calcium waters.
===Water adjusting goals===
When thinking of water chemistry for brewing there are 2 seperate considerations. Firstly, and most importantly, that the dissloved ion profile (mostly Ca ions) be condusive to attaining the correct mash pH in the range of 5.2-5.6. Secondly that dissolved ion concentrations A. Not have a negative flavour impact and B. Where required have a positive or desired flavour contribution. It is no point obsessing over the optimal Sulphate to Chloride ion ratio if excessive tannins are extracted due to a high pH mash!
===Adjusting Water===
