n ground coffee the oils are standing in "open packages," escaping
into the air and absorbing moisture, etc., necessitating quick use
or confinement in air proof and moisture proof protection.

BREWING. From scientific researches by the National Coffee
Roasters' Association, including the first chemical analysis on
record of brewed coffee, produced by various brewing methods, the
fundamental principles of coffee making have been clearly
established. These principles are simple, and when once understood
equip any person to intelligently judge the merits and defects of
the various coffee making devices on the market. They constitute
the law of coffee brewing, and may be stated as follows:

Correct brewing is not "cooking." It is a process of extraction of
the already cooked aromatic oils from the surrounding fibrous
tissue, which has no drinkable value. Boiling or stewing cooks in
the fibre, which should be wholly discarded as dregs, and damages
the flavor and purity of the liquid. Boiling coffee and water
together is ruin and waste.

The aromatic oils, constituting the whole true flavor, are
extracted instantly by boiling water when the cells are thoroughly
opened by fine grinding. The undesirable elements, being less
quickly soluble, are left in the grounds in a quick contact of
water and coffee. The coarser the grind the less accessible are the
oils to the water, thus the inability to get out the strength from
coffee not finely enough ground.

Too long contact of water and coffee causes twang and bitterness,
and the finer the grind the less the contact should be. The
infusion, when brewed, is injured by being boiled or overheated. It
is also damaged by being chilled, which breaks the fusion of oils
and water. It should be served immediately, or kept hot, as in a
double boiler.

Tests show that water under the boiling point, 212 deg., is
inefficient for coffee brewing, and does not extract the aromatic
oils[378]. Used under this temperature, it is a sure cause of weak
and insipid flavor. The effort to make up this deficiency by longer
contact of coffee and water, or repeated pouring through, results
in no extraction of the oils, but draws out undesirable elements,
such as coffee-tannin, which is soluble in water at any temperature
an