often added to municipal water supplies to prevent tooth
decay and is harmless for brewing purposes. Chloride is
eluted next, and at levels above 250 mg/L it has been
found to enhance the sweetness of beer. However, it may
also hamper yeast flocculation. Nitrate was once thought
of as a problem in the brewing process, but it has since
been discovered that it is the nitrite produced from nitrate
that affects yeast metabolism to cause weak and incomplete
fermentation. Sulfate is found naturally in water but imparts
a sharp, dry edge to well hopped beers and is therefore
kept to a minimum. Finally, phosphate is present in the
malt and buffers the mash at a slightly acidic pH.