damage (p. 255).
Water For Making Tea
and Coffee
Brewed tea and coffee are 95–98% water, so
their quality is strongly influenced by the
quality of the water used to make them. The
off-flavors and disinfectant chlorine
compounds of most tap waters are largely
driven off by boiling. Very hard water, high in
calcium and magnesium carbonates, has
several undesirable effects: in coffee, these
minerals slow flavor extraction, cloud the
brew, clog the pipes in espresso machines and
reduce the fine espresso foam; in tea, they
cause the formation of a surface scum made
up of precipitated calcium carbonate and
phenolic aggregates. Softened water
overextracts both coffee and tea and gives a
salty flavor. And very pure distilled water
gives a brew best described as flat, with a