Waters nearest oceans are more likely to have higher salt contents than others. Waters high in salt are unsuitable for brewing because of their effect on yeast cell chemistry, as well as their unpleasant effects on beer flavour. Unlike many other ions found in brewing water, neither the sodium nor the chloride ions contribute significantly to the activity of mash enzymes, kettle boil coagulation, or yeast metabolism. Both these ions do, however, contribute immensely to flavour and taste perception in the final beer. Sodium ions are generally considered the less desirable of the two. Sodium ions give the familiar “salty” notes and coarseness and harshness that most brewers try to avoid. Sodium ions are considered usually best restrained to a maximum of 25 mg/l, although some stouts will taste pleasant with levels up to 150 mg/l.
The flavour threshold of sodium chloride in beer is 200 mg / l in beer. Chloride is contributed to beer by both malt and brewing liquor. Some brewers add calcium chloride or sodium chloride in the brewhouse to provide palate smoothness.