tic and flavoring constituents is always
evident in the cup valuation, and introduces a controlling factor in the
production of an individualistic drink.

_Coffee Extracts_

The uncertainty of the quality of coffee brews as made from day to day,
the inconvenience to the housewife of conducting the extraction, and the
inevitable trend of the human race toward labor-saving devices, have
combined their influences to produce a demand for a substance which will
give a good cup of coffee when added to water. This gave rise to a
number of concentrated liquid and solid "extracts of coffee," which,
because of their general poor quality, soon brought this type of product
into disrepute. This is not surprising; for these preparations were
mainly mixtures of caramel and carelessly prepared extracts of chicory,
roasted cereals, and cheap coffee.

Liquid extracts of coffee galore have appeared on the market only soon
to disappear. Difficulty is experienced in having them maintain their
quality over a protracted period of time, primarily due to the
hydrolyzing action of water on the dissolved substances. They also
ferment readily, although a small percentage of preservative, such as
benzoate of soda, will halt spoilage.[182]

So much trouble is not encountered with coffee-extract powders--the
so-called "soluble" or "instant" coffees. The majority of these powdered
dry extracts do, however, show great affinity for atmospheric moisture.
Their hygroscopicity necessitates packing and keeping them in air-tight
containers to prevent them running into a solid, slowly soluble mass.

The general method of procedure employed in the preparation of these
powders is to extract ground roasted coffee with water, and to evaporate
the aqueous solution to dryness with great care. The major difficulty
which seems to arise is that the heat needed to effect evaporation
changes the character of the soluble material, at the same time driving
off some volatile constituents which are essential to a natural flavor.
Many complex and clever processes have been developed for avoiding these
difficulties, and quite a number of patents on processes, and several on
the resultant product, have been allowed; but the commercial production
of a soluble coffee of freshly-brewed-coffee-duplicating-power is yet to
be accomplished. However, there are now on the market several
coffee-extract powders which dissolve readily in water, giving quite a
fair approximation of