Boiling water is a very important desideratum in the making of a cup
of good coffee or tea, but the average housewife is very apt to
overlook this fact. Do not boil the water more than three or four
minutes; longer boiling ruins the water for coffee or tea making, as
most of its natural properties escape by evaporation, leaving a very
insipid liquid composed mostly of lime and iron, that would ruin the
best coffee, and give the tea a dark, dead look, which ought to be the
reverse.
Water left in the tea-kettle over night must never be used for
preparing the breakfast coffee; no matter how excellent your coffee
or tea may be, it will be ruined by the addition of water that has
been boiled more than once.