ADULTERATION AND DETECTION.
In commerce coffee is to be met with in three conditions--Raw or
unroasted, Roasted and Ground--and, as may be inferred, it is in the
latter condition that it is most liable to the chief adulterations,
so that with the raw and simply roasted coffee the public analyst
will have very little to do, his services being principally required
in dealing with ground coffee alone. But at the same time it is also
subject to much manipulation and sophistication in the two first
conditions also, scarcely any dietic article being so persistently
adulterated. From the time of picking and preparing coffee for market
until it finally reaches the table of the consumer, there is probably
no article of diet subjected to more or as many forms of manipulation,
sophistication, substitution and adulteration as coffee. The producer
mixes one variety with another, the refuse of the old and inferior with
the new and choice, while the commission agent at the shipping ports
manipulates it again by changing the grade or altering the quality by
running one grade with another in order to complete his consignment.
Again, on its arrival in the consuming countries it is frequently
emptied out of the original packages, separated or run together as
required, the bags turned inside out, and the marks altered in order
to conceal any stained or damaged in transit. All “bilge-water”
or otherwise damaged coffee being picked over, the musty beans set
aside, milled or cleaned, rematted or rebagged as the case may be, and
eventually sold as sound, but which no process of roasting or glazing
can eradicate. But while almost all varieties pass through more or
less manipulation or substitution, from the producing to the consuming
countries, it does not always follow that it is detrimental to the
coffee.
RAW OR GREEN COFFEES.
=Rios=--Are most subject to sophistication by altering the color
from light to green and dark to meet the demand for each particular
kind, the light Rios being converted into dark by the application
of a preparation of “bone black,” and into yellow or golden by the
use of chromate of lead, or into green by a combination composed of
both compounds. This dangerous and iniquitous practice is resorted to
in order to cater to the prejudices of dealers and consumers in the
different sections of the country for “Light,” “Dark,” “Green” and
“Golden Rios,” as the case may be. The cosmetic is best detected by the
simple process of washing in a little warm water and rubbing with a dry
towel, exposing the natural color of the bean, whatever the original
may be, or by cutting the bean in half and seeing if the color runs
through.
=Maracaibos=--In the raw or natural state are principally substituted
with large, white-bean Santos, Savanilla, San Domingo, Mexican,
Salvador or other Central American coffees as well as by transferring
the lower into high-grade bags. While La Guayras are usually polished
or “soapstoned,” and converted into Rios when the finer grades of the
latter are scarce or high.
=Javas=--Are generally either substituted, mixed, sweated or colored
artificially. In the first case any large, whitish, yellowish or
brownish variety, such as Maracaibo, Savanilla and Santos is used
for the purpose or mixed with it in the natural state, and can only
be detected by a familiar knowledge of the genuine bean. The lower
and paler grades of Java, such as Lahats and Maccassars are usually
“colored” or “sweated” for the purpose of imparting an aged appearance
or the so much desired brown color, other spongy-bean coffees that
easily absorb, and retain the coloring matter being frequently
subjected to the same processes. While the higher grades are more often
substituted one for the other by changing the mats, such as replacing
a Preanger with a Timour, an Ankola with Padang or Singapore. When
simply colored as before described the washing it with a little water
and rubbing with a dry towel will expose the cosmetic, or better still
by cutting the suspected bean open with a sharp pocket-knife, examining
it through; if not of the same color to the core it is undoubtedly
doctored. Another method, when the coffee is mixed with Savanilla or
other light bean coffee, is to place a sample of the suspected coffee
on top a vessel of water, in which case the hard, solid-bean Java
will sink to the bottom and the light-bean substitute float on top.
“Sweated” Javas are browned by placing any fair-sized, light-colored
variety such as Lahat, Maccassar, ordinary Jamaica or Savanilla in
a zinc or iron-lined room or case surrounded on all sides by pipes,
through which steam passes and subjecting them to an intense heat,
the process causing the--whatever little volatile oil this class
of coffee contains--to exude and impart a dark, muddy-red color to
the beans. This sophistication is best detected by the unnatural,
repulsively reddish color produced by the process, by their light
weight and irregular, unsightly appearance in the hand as well as by
their nauseous, almost sickening flavor, developed by the volatile oil
and the zinc, and which is evidently prejudicial to the health of the
consumer.
=Mocha Coffee.=--Probably there is no single variety of coffee grown
more generally counterfeited or adulterated than Mocha in the raw or
unroasted state, owing to its limited supply and high commercial value.
In addition to the manipulation and substitution which it undergoes
at the ports of export, by the addition or substitution of small-bean
Wynaad, Malabar, Ceylon, Bourbon and other African varieties annually
shipped to Aden for the specific purpose of conversion into Mocha,
that it has become a difficult matter to determine what is true Mocha
and what is not. The substitutes are first separated from the regular
crops and then carefully picked over and assorted by hand, the better
to adapt them to their respective markets, and then packed in the
unique and peculiar packages which distinguish the true article from
all others. It had at one time been considered as next to impossible to
tamper with or imitate these packages without detection, composed as
they are of a coarse vegetable material, sewed with a fibrous substance
that becomes excessively hard and tough by age; but modern ingenuity
has found a way in the countries of consumption to cut this “Gordian
knot,” first by a process known to the initiated as “stove-piping,”
by which a portion of the genuine coffee is run out of the original
package with an iron tube resembling a “coffee tryer,” inserted at one
end of the bale and a spurious article composed of some small-bean
variety, such as Santos, Maracaibo or Guatemala, poured in its place
and the puncture closed up. Another ingenious method is to soften the
fibrous cord of which the withes are made, and with which the bales
are sewn, by a process known as “steaming,” by which they are softened
and drawn out, the bales being easily opened entire and the contents
substituted by the introduction of one or other of the same class of
coffees already mentioned, and even by small-bean Rios, particularly
when the former kinds are high or difficult to procure. These glaring
forms of adulteration and substitutions practiced in Mocha coffee may
be readily detected by a comparison of the mixture or contents with a
sample of the genuine bean, which is invariably small, round, uniform
and symmetrical, varying in color from a rich olive-green cast, almost
translucent when new, and a bright-yellowish hue when old, being at the
same very clean, and attractive in the hand. While the adulterants and
substitutes are much larger, more irregular and varying in size, style,
form and color, from a dark or grass-green to a pale white, according
to the age and nature of the coffee used.
There has recently been discovered another and very ingenious coffee
fraud, in which the raw beans look quite natural, but yield no coffee
liquor on infusion. On close inspection these spent or exhausted beans
resemble artificial coffee beans composed of baked dough colored, but
a microscopical examination disproves this supposition. The beans are
genuine coffee beans, but the cells show a remarkable freedom from
caffeine and the oil of coffee, indicating that they had been steeped
in water, so that on the microscopical examination being supplemented
by a chemical analysis, the result showed that almost every valuable
property of the coffee had been removed from the beans, evidently for
medicinal purposes or the manufacture of some extract of coffee, after
which they are re-dried and disposed of to roasters and unscrupulous
dealers as sound coffee. The beans of such coffee look quite natural,
but on close inspection are found to be tough and light, yielding
a watery and flavorless liquid on infusion. A patent has also been
recently obtained the purpose of which is to impart to coffee beans
by a summary operation the properties and characteristics possessed
by coffee which has been stored and kept under favorable conditions
for a comparatively long period of time. The process of maturing or
“aging” the coffee consisting in spreading out the raw beans in a thin
layer between alternate layers of damp bags or other textile material
first by sprinkling a number of bags with water, and piling them one on
top of the other until they have all become uniformly moistened, then
spreading out one of the bags and laying on it a dry bag upon which is
placed a layer of green coffee, another dry bag being placed over it
and a damp bag on that again, and so on to any desired height. The pile
of bags and coffee thus formed is then compressed in order that the dry
bags may absorb the moisture from the damp bags and also become damp,
thus maintaining the coffee beans in their confined space until the
desired maturing or aging effect has been produced.
ROASTED COFFEES
Are chiefly sophisticated by mixing or substituting lower with
high-grade coffees, and by coating or glazing the beans with some
obnoxious compounds as previously described. Many of the so-called
Javas and other high-sounding-name coffees now in the market so
much vaunted and extolled being nothing more than combinations of
Santos, Maracaibo and other medium grades, some of the most reputable
consisting merely of Santos and Java in the proportions of 40 per
cent. of the former to 60 per cent. of the latter. The distinguishing
features of the raw or natural bean being largely altered in the
process of roasting, making it a difficult matter for any but experts
to detect this most common form of adulteration, an acquaintance with
the original flavors of the different varieties being the only sure
means of detection.
[Illustration: WASHING COFFEE.]
Some years since, there was invented a bean resembling that of roasted
coffee, made from dyed plaster of paris, which was intended for
admixture with coffee, and at the present time a far more dangerous
fraud is being perpetrated in the already too wide field of coffee
adulteration. It is that of a bogus or artificial bean, resembling
that of whole roasted coffee, which, on analysis, proves to be largely
composed of wheat flour, mixed with a glutinous compound of cracker
dust, paste and molasses, moulded in the form of the true coffee bean
of commerce and flavored with a weak solution of caramel or chocolate.
These spurious coffee beans are not, however, intended to supply in
themselves a beverage which from any similarity of appearance, taste
or effect might form a substitute for coffee and cannot therefore be
regarded as such, but are intended solely as an adulterant of whole
roasted coffee. It is readily detected by close inspection in the hand,
but still more so in the cup, tasting as it does more like a decoction
made from burnt dough and molasses. When dissolved in boiling water
it yields a blackish, muddy liquor akin to slop, leaving a thick,
greasy residue in the bottom of the vessel. The custom of coating or
“glazing,” now so much in vogue among roasters and dealers, may also
be classed among the many, but milder forms of adulteration, which,
though ostensibly claimed to protect the pores of the coffee from the
oxydizing influences of the atmosphere, preserve its aroma, and at the
same time clarify the infusion, is in reality, in nearly all cases,
resorted to for the purpose of disguising or concealing the defects
of artificially-colored, stained, damaged and immature or “quakery”
coffees, or for adding an extra weight of from 5 to 6 per cent. to it.
GROUND COFFEES
Are subject to the most extensive adulterations, all being more or less
sophisticated or adulterated in one form or another, chief among which
is that of the admixture of the roasted and ground roots of Chicory,
Dandelion, Carrot, Parsnip, Beet and other leguminous vegetables.
Peas, Beans, Rye, Rice, Wheat, Barley and various other cereal grains,
including the seeds of the broom, fenugreek, iris and acorn. These
various roots and seeds, with many more similar substances, have
not only been used as adulterants, but under various high-sounding
names several of them have been introduced as substitutes for coffee.
But so far not a single one of them have either merited or obtained
any success as such, their sole effect being to bring coffee into
undeserved disrepute as a pleasing and agreeable beverage with the
public.
SUBSTITUTES AND ADULTERANTS.
Among the numerous substitutes and adulterants in use for coffee may be
mentioned first:--
=Rye Coffee.=--Prepared from roasted rye and a little butter ground
fine, and put up in packages.
=Rice Coffee.=--Made from roasted rice in the same manner as the former
and considered a very good substitute.
=Malt Coffee.=--A preparation made from malt, which is first soaked
in water at 40 degrees and dried in a coffee roaster until the grains
assume a glossy-brown color is used as a substitute for the coffee of
commerce, the finished product, when ground and infused, is claimed to
be a passable coffee substitute.
=Currant Coffee.=--Manufactured from the seeds of that fruit, washed
out of the cake left in making currant wine, then roasted and ground,
but principally used as an adulterant.
=Gooseberry Coffee.=--Prepared from the seeds of that fruit in the same
manner and used as an adulterant also.
=Holly Coffee=--Is made from the berries of the common holly, roasted
and moistened with a little lemon juice.
=Acorn Coffee=--Is prepared from acorns, deprived of their shells,
husked, dried and roasted in the same manner as regular coffee.
=Sassafras Coffee.=--Manufactured from the fruit or root of that plant,
or from the bark, cut up, dried and roasted, the decoction being very
wholesome, and a specific for skin diseases.
=Beechmast Coffee.=--Made from the roasted and ground roots of the
beechmast, and also claimed to be very wholesome.
=Beet-root Coffee.=--Principally used as an adulterant; is prepared
from the yellow beet-root, sliced, dried in an oven and ground with
genuine coffee.
=Almond Coffee=--Is made from either rye or wheat, roasted with almonds
and a very small quantity of cassia buds, making a very good substitute.
=Bean Coffee=--Is prepared from ordinary horse-beans, roasted along
with a little honey and burnt sugar, a small quantity of cassia buds
being frequently added when removed from the fire, the whole being
stirred until cold.
=German Coffee=--Is chiefly made from chicory roasted and ground fine,
and used either as a substitute or an adulterant of the regular coffee
of commerce.
=Coffee-pulp Coffee.=--In Arabia the pulp of the berries, which
constitutes about twenty per cent. of the prepared coffee, is dried
and shriveled up by a method peculiar to Arabia. This product is known
by the distinct name of _Kishr_, a decoction of which forms the common
beverage of the poorer Arabs.
=French Coffee.=--What is known and celebrated as “French Coffee” is
made from a mixture of coffee and caramel, which must be packed in
tins, as otherwise the hygroscopic properties of the caramel will cause
it to absorb moisture, and thereby run to decomposition.
=Pelotas Coffee=--Is also prepared from ground acorns and sold under
the name of Pelotas, but is exceedingly dark in liquor, wild and
insipid in flavor.
=Corsican Coffee=--Is made from the roasted seeds of the Knee-holly,
and used extensively on that island as a substitute for the regular
coffee of commerce.
=Egyptian Coffee=--Is prepared from the common Chick-pea roasted,
ground and mixed with genuine coffee in equal parts, being more of an
adulterant than a substitute.
=Mesquite Coffee.=--It has been recently claimed that a species of
coffee may be produced from the “Mesquite plant” found growing in wild
abundance in Texas, Arizona and New Mexico, but so far no positive
results have been reported.
=Dandelion Coffee.=--The root of the Dandelion, first dried, roasted
and ground, is also extensively used as a substitute for coffee, and is
claimed by many physicians to be much preferable to chicory for that
purpose, its infusion, decoction and extract being frequently employed
as a tonic and aperient, especially in disorders of the liver and
digestive organs.
=Spent Coffee=--Prepared from “exhausted” coffee grounds which are
dried and re-atomized by the transforming hand of modern chemistry, put
up in shiny packages under seductive titles, and from which the deluded
and over-confiding consumer endeavors to extract a desired beverage.
=Mussenda Coffee.=--A patent has recently been granted in France, the
object of which is to substitute the berry of the _Mussenda_ plant
for the various substances now used for mixing with ground coffees,
by which the berries are roasted with the coffee in any desired
proportions, usually from ¹⁄₃ to ²⁄₃ Mussenda, or ³⁄₄ coffee to ¹⁄₄
Mussenda. During the roasting process a small quantity of Caramel is
added to improve the flavor, the compound being then ground and put
up in cans, possessing at least one good recommendation, that of not
containing any injurious properties.
=Canada Peas=--Which is the most extensive form of adulteration, are
first roasted in the same manner as coffee, but requiring a much
longer time and more care, as the shell of the pea does not assume a
coffee-color until the inside is overdone, and must be judged by the
inside appearance, being brittle and a little darker when broken than
coffee, but when ground they are dry and dusty, on which account they
make an excellent compound with chicory, keeping it from forming into
lumps and making it assume a uniform color. Wheat, rye or barley may be
substituted or added to this compound without affecting it, the method
of treatment being identical. There being but little aroma to protect
and none to save, the virtue of this compound lies altogether in the
healthy properties of the cereal used, not in the flavor of the liquid.
=Essence of Coffee=--Is simply an article of manufacture, containing
no coffee, but intended for use with coffee for the purpose of
imparting color and as a clarifying agent. It may be prepared at will
from any cereal before named, bread raspings or burnt cracker dust,
but is chiefly composed of carbonized corn, that is, corn roasted
to blackness. The material from which it may be prepared is first
roasted, ground fine and spread out thinly over a large surface, and
then covered with burnt sugar or molasses while boiling hot, the whole
forming a large cake, which when thoroughly cooled is broken into
pieces and reground in an iron mill until reduced to a dust, after
which it is put up in packages or barrels for use in coffee. It is also
used extensively as an adulterant in ground coffee, and when made from
good stock it is not objectionable, possessing excellent coloring,
sweetening and clarifying properties.
=Coffee-leaf Coffee.=--A decoction made from the leaves of the coffee
shrub has long been used in the Eastern Archipelago, and has more
recently been introduced among the coolies of southern India, and a few
years since attracted considerable notice, being recommended as a new
article of import to become a cheap substitute for tea. There seems
to be no doubt that coffee leaves contain the principle caffeine in
sufficient abundance for the making of a valuable beverage, but the
presence of an unpleasant senna-like odor militates greatly against its
popularity as a regular drink, and there exists also the difficulty
that of depriving the tree of its foliage damages the crop of berries
and injures the tree itself. On berry-producing trees therefore only
the leaves obtained in the ordinary pruning operations would be
available, and these would seem to yield so small a supply as not to be
worth the cost of collection, while growing the shrubs for the leaves
alone would be a very questionable undertaking. Yet there appears to be
no valid reason why in the event of the berry crop failing a portion at
least of the leaves might not be gathered and prepared in the form of
coffee if any means can be invented for removing the objectionable odor.
=Whey Coffee=--Another very novel substitute for coffee is prepared
of whey from milk, which is evaporated down in open vessels or vacuum
pans until most of the water is driven off and a thick paste remains.
During the process the whey is kept constantly stirred, the stirring
being continued until the pasty mass becomes cold, when it is rolled
into cakes and dried at a temperature of boiling water, after which it
is broken up and moulded into pieces about the size and form of coffee
beans. The next operation is that of roasting, which is more preferably
performed by first mixing them with an equal quantity of raw coffee,
the roasting process thus turning the whey-paste beans into a rich
brown color, which on cooling are ground with another percentage of
coffee. The compound yields a pleasant and agreeable beverage and may
find some use as a harmless if not really nutritious ingredient in the
lower priced coffee preparations.
In Brazil and other South American countries the fruit of the Wax
palm is used extensively as a substitute for coffee, being very rich
in caffeine and possessing nutritious properties, while recently a
substitute for coffee has been introduced to England and the continent
of Europe under the name of “Mochara,” which is simply a preparation
made from ripe figs, roasted and pulverized, which is sold at about
half the price of coffee. Another illustration of the modern craze
for replacing every genuine article by an inferior substitute is to
be found in the announcement of a company to work a recent patent
for making coffee out of dates. In New Zealand the berries of the
_Coprosma_ have been proposed as a coffee substitute, while the seeds
of the _Cassia_ have been lately imported into England from the river
Gambia and sold there under the name of “Negro Coffee.” But although
such substitutes and admixture are demanded, yet it appears to be
impossible to replace coffee altogether, all the elaborate attempts
made by the French chemists during the wars in the early part of this
century being unsuccessful in providing any approximate substitute for
coffee.
=Kola-nut Coffee.=--The diminishing production of coffee in Java,
Ceylon, and other countries of East Indies has given rise to the
suggestion that the cultivation of the Kola-nut as substitute for
coffee should be undertaken, which not only as a stimulant, but as an
article of food, possesses the essential properties of coffee, and is
even said to be richer in the active principle, _caffeine_. Heretofore
this product has been raised chiefly for medicinal purposes only, but
its acceptability as a stimulating and nutritious beverage is rapidly
growing, possessing as it does a high value, because of its power of
enabling men to sustain great effort as well as to endure long fasting.
It is fast finding a place in commerce in the same order as that
held by coffee, the beverage being called at the present “Kola-nut
Coffee,” but the term “Kolatina,” has recently been proposed as more
appropriate for the decoction, and to which there can be no reasonable
objection. The beverage prepared from the Kola nut resembles that
made from coffee, and is both pleasant and agreeable, and for persons
troubled with weak indigestion “Kolatina” is found to be better adapted
than either tea or cocoa. This is the bean which Stanley speaks in
several of his works on African exploration as possessing much greater
sustaining power than either tea, coffee, or cocoa; the natives, he
states, carry these beans in their pockets and eat them during long
marches. The beans are first ground and put up in packages, with
directions for making the infusion, one teaspoonful being sufficient
for a cup of Kolatina. A concentrated essence is also made from the
beans, and an acerated drink called “Kola champagne,” very agreeable to
the taste and recommended by physicians.
=Chicory=--The common root of the Endive or “Succory” plant, as used
along with coffee was originally a Dutch practice dating back to over
a century ago, but for many years after the nature of Chicoried coffee
was kept a profound secret by the Dutch dealers until 1801, when the
secret was first disclosed. The fact that for over a hundred years it
has been successfully used as a substitute for and recognized addition
to coffee, while in the meantime innumerable other substances have been
tried for the same purpose and abandoned indicates that it must be
agreeable, if not beneficial, to many constitutions besides imparting
to coffee additional color, body and pungency, and may, by acting as
a sedative, tonic and diuretic, modify its stimulating and exciting
effects, and is at least in very general, almost universal, use at
the present time. It is extensively cultivated in Belgium, Holland,
France, Germany and other European countries, being principally
prepared from the old, stout and white roots of the plant, which
after washing are sliced into small pieces, and kiln-dried, in which
condition it is usually sold to the chicory roasters, by whom it is
parched or burned, until it assumes a deep-brown color, after which it
is ground, the fine dust being separated from the coarse and granulated
parts. In its external characteristics it closely resembles ground
coffee, but is entirely destitute of its pleasing and aromatic odor,
neither does it possess any trace of the alkaloid--caffeine--which
give their peculiar virtues to coffee, tea and other diet drinks. It
occupies a peculiar position, however, since very many coffee consumers
deliberately prefer an admixture of chicory with coffee to the pure
article alone, notwithstanding that it is entirely devoid of the
essential oil for which coffee is so valued. Differing diametrically
in their botanical nature and chemical composition as well as in their
physiological properties and action. Again, coffee is the fruit of a
tree, while chicory is the root of a herbaceous plant, and it is a
well-established fact that of all parts of either vegetables or plants
the fruit and seeds possess the most active and nutritious properties.
This is no doubt due to their being freely exposed to the influence
of light and air--agencies which invariably promote chemical changes
in the plant itself and so effect the elaboration of those complex
organic substances on which the activity of all plants depends. While
on the other hand it is manifest that, as roots are concealed from
these powerful agencies, they cannot be richly endowed with active
properties, there being but few roots containing either alkaloid or
volatile oil--the properties which give to coffee its unique virtues.
The distinction therefore between the properties of the seeds and
roots of plants in general is very important, and especially so in
the case of coffee and chicory, the infusion of the latter being
heavy, black, mawkish and entirely destitute of aroma; that of the
former being light, rich, fragrant and refreshing. Coffee containing
three active principles: caffeine, volatile oil and tannin, chicory
possessing no such analogous constituents. Coffee exerting very marked
and highly important physiological effects of a beneficial character in
the human system, while there is not a single proof that chicory exerts
any one of these effects, it being very questionable, in the contrary,
whether the properties it does possess are not really injurious.
None of these or analogous principles are to be found in any of the
substitutes or adulterants of coffee, so that the latter cannot possess
a single one of the peculiar and beneficial properties of coffee, being
simply a deception on the stomach of the consumer.
Chicory contains neither _caffeine_ nor essential oil like coffee, and
is neither exhilarating nor pleasant in taste, while on some persons
it acts as an irritant and purgative. Some so-called coffees contain
large quantities of it, even to the extent of 95 per cent., which it
would be more correct to call such a mixture “adulterated chicory,”
rather than coffee, which term it seems entitled to only as a matter
of courtesy, chicory being in its turn also subject to adulteration
in many forms, two very common adulterants being beet-root and
mangel-wurzel. As to the nutrition possessed by chicory, it contains
only about one-half the nitrogenous substances of coffee and even that
quantity in no way benefits the consumer, as these substances are
insoluble in water and are wasted in the infusion. It has been proved
also that even the chicory itself is extensively adulterated, as all of
the substances found in adulterated coffee have also been discovered
in ground chicory. Viewed under a magnifying glass the component
fibres and elementary structures of the different substances used in
the adulteration of coffee present peculiarities and characteristics
that enables the experienced observer to identify without difficulty
the particular substitute or adulterant employed. The principal
adulterant, chicory, being readily distinguished by the size, form,
and ready separation of the component cells of the nut, as well as by
the presence of an abundance of spiral vessels of a dotted form. Whole
roasted beans, peas and cereals may be best detected by the respective
size, form, texture and other characteristics of the starchy granule,
of which such substances are chiefly composed.
In minute structure true coffee is so distinct from all other vegetable
substances that it is readily recognizable by means of the microscope,
and as the roasting process does not destroy its distinguishing
peculiarities, microscopic examination forms the readiest method of
determining the genuineness of any suspected sample. The true coffee
bean consists of an assemblage of vesicles or cells, angular in
form, which adhere so firmly together that they break up into pieces
rather than separate into distinct and perfect cells. And, again, by
microscopical, physical and chemical tests the purity of coffee can
be still further determined with perfect certainty. The mixture of
chicory with coffee is best detected by the aid of the microscope,
the structure of both which they retain after torrefaction being very
characteristic and distinct. The granules of coffee remain hard and
angular when steeped in water, to which they communicate but little
color, while chicory on the other hand by swelling up and softening
imparts a deep brown color to the water, the specific gravity of
chicory being also much lighter than that of coffee.
All of the pseudo patent or proprietary ground coffees, put up in
bulk or packages, and recommended to the consumer by high-sounding,
seductive names and attractive labels, which are annually palmed off
in such vast quantities, consist of nothing more than a combination of
these adulterants with genuine coffee. So much so that it may be safely
said that wherever grinding is done it may be safely set down that
more or less adulteration is practised, the ground coffee being put up
in packages or in bulk form. The average basis for the compound being
composed of the following proportions to every 1,000 pounds: chicory,
100; rye, 200; peas, 400; coffee, 200, and other substances 100 pounds.
According to some English chemists, coffee is adulterated in that
country, outside of chicory, with such substances as roasted peas,
beans, carrots, turnips, parsnips, potatoes, acorns, beets, lupins
and even fragments of the baked livers of oxen and horses. To such an
extent is the practice carried there, that it is next to impossible to
procure a pound of pure coffee there at almost any price. The evil also
flourishes to a great extent in this country, but with the exception
that nothing worse than roasted rye, peas, beans and cereal grains are
chiefly used for its adulteration. With regard to the propriety of
selling chicory with coffee, it may be stated that while it certainly
is not right to sell a mixture of coffee with chicory under the name
of pure coffee, and unreasonable to compel the manufacturer or vender
to specify approximately the proportion of chicory contained in the
mixture, this latter is especially desirable, inasmuch as chicory
is far cheaper than coffee, and it is, therefore, necessary to
protect the public against having chicory palmed off on it for pure
coffee. According to the best authorities, coffee, when pure, is a
most valuable ingredient of our food, owing to its agreeable flavor,
pleasing odor and refreshing and gently stimulating properties, which,
if not absolutely necessary, is at least a most desirable constituent
of our daily dietary, and any one that deprives it of its true
qualities by adulteration or substitution inflicts an injury more or
less grave on the public health, because the adulterants are _claimed_
not to be poisonous--that is, directly--but only indirectly injurious.
The offense is thought little of, and never punished in this country,
with the result that the nefarious practice is rather encouraged
than repressed. So that, in considering the many evils of coffee
adulteration, we must not overlook the fact that coffee is not only
a beverage, but also a drug, antagonistic in action to the _alkaloid
morphia_, as well as to other alkaloids of like nature, so that in
cases of poisoning its adulteration may lead to the failure of medical
treatment, even to the extent of the loss of life.
The operation of roasting also tends to make coffee soluble in boiling
water, as when Raw coffee is perfectly exhausted by means of boiling
water it yields up 25 per cent. which passes into solution, while
Roasted coffee, on the other hand, when completely exhausted by means
of boiling water, yields up 39 per cent. of soluble matter. These
figures appear rather high, as in actually using coffee as a beverage
we are not in the habit of making anything like a complete extraction,
only some 10 to 12 per cent. of the coffee passing into the liquid.
From these the facts it will be perceived that the chemical character
of coffee provide fairly satisfactory criteria for the recognition of
many species of adulteration, the absence of starch alone in genuine
coffee offering in itself a character which enables the analyst to
at once deal with the whole class of possible adulterants, including
many species of grain, while the absence of more than traces of sugar
in Roasted coffee can likewise be turned to excellent account inasmuch
as Chicory contains no starch, but is highly saccharine even after
roasting, the percentage of sugar in Roasted coffee ranging from 0.0
to 1.1, while in Roasted chicory the quantity of sugar ranges from 12
to 18 per cent. The proof of this character is best made by the aid of
the copper-reduction test, for which purpose a standard solution of
copper is required, which may be prepared by dissolving 34.65 grams
of crystalized sulphate of copper in 200 C.C. of water and adding to
it 173 grams of double tartrate of potash and soda, with 400 C. C.
of a solution of caustic soda, the whole being subsequently diluted
with water so as to occupy a litre. The standard solution of copper
made in this manner is of such a strength that 10 C. C. are reduced
by .050 grams of grape sugar, the best method of using this solution
being to take a known volume of it, say 10 C. C. accurately measured
out, and dilute it with three or four times its volume of boiling
water and then dropping into the boiling copper solution, which is to
be added, until the point is just reached when the copper solution is
exhausted, and as the reduction of the copper-salt to the state of
red sub-oxide of copper progresses, the precipitate will accumulate,
and at the same time the blue color will fade from the solution. The
last delicate reading is finally effected by half of the reduction
between the ferro-cyanide of potassium and copper solutions, for which
purpose a little of the liquid is filtered, acidified slightly with
acetic acid and tested with a drop of the solution of the ferro-cyanide
of potassium. In this triturate, as in all like cases, a rough and
rapid estimation is first made, and then a second operation when
the quantity is approximately known to make a delicate and careful
reading of the exact point. Thus if 100 parts of coffee when infused
yield sensibly more than 1 per cent. of sugar, then the presence of
chicory or other adulterant may be strongly suspected and a rough
calculation of the quantity made. The fact that coffee extract is
devoid or almost devoid of sugar, while many of the other natural
products yield saccharine extracts, makes itself manifest in many ways,
and the specific gravity also of equal quantities of an infusion of
coffee being very much lower than the specific gravity of an infusion
of chicory and the other principal substances used in the adulteration
of ground coffee. Chicory also possessing greater coloring power than
coffee, for which reason this character may be rendered available in
the testing of coffee, as not only does chicory color water more deeply
than coffee, but it colors it with greater rapidity, the oil contained
in the coffee hindering the solution of the coloring matter by the
water, whereas chicory, which contains no oil, imparts its coloring
matter to water with great readiness. All of which tends to render the
color-test, when properly applied, the easiest and most available for
the detection of chicory or other substances in coffee.
What is known as the “Ash test,” is as follows: Pure coffee when
incinerated or burned, yields about 4 per cent. of ash on an average,
while the ash of chicory and other adulterants used in coffee amounts
to between 5 and 6 per cent. of the residue, the ratio of soluble to
insoluble ash being inverted when dissolved in water thus:--
Ash of Coffee. Ash of Chicory.
Soluble, 3.24 Soluble, 1.74
Insoluble, 0.76 Insoluble, 3.52
From this analysis it will be observed that the average ash of coffee
when incinerated is about 4 per cent., 3.24 of which is soluble in
water, and 0.76 insoluble, more than half of the entire ash consisting
of potash in combination with carbonic and phosphoric acids. Magnesia
amounting to about 8 and lime to about 4 per cent. of the whole, while
it is claimed that soda and silica are entirely absent from coffee ash,
great stress being laid on this circumstance. The ash of chicory, on
the other hand, which is the main adulterant of coffee, amounts to 5.06
when incinerated, 1.74 per cent. of which only is soluble in water, and
3.32 insoluble, being almost an inversion of figures and from which it
may be easily understood why the examination of the ash alone would
suffice to distinguish between coffee and chicory, and from which
it may readily be determined, an examination of the ash test alone
sufficing to distinguish pure coffee from the adulterated compounds.
Another unerring test, known as the “Color test,” is to prepare a
saturated solution of common salt and mix a small quantity of the
coffee to be tested with ten times its weight of the solution in a
test-tube at least three quarters of an inch in diameter, shaking it
repeatedly so that the coffee may be thoroughly wetted, and then allow
the tube to stand for half an hour. Next, closely observe the color of
the liquid and the quantity of coffee floating on the surface as well
as the amount deposited in the tube. If the color be a very pale amber
and almost all of the coffee floats on top, the sample may be assumed
to be pure, but if of a decidedly dark-yellow or brownish hue, it
clearly indicates the admixture of chicory or some similar adulterant,
in which case there is also a larger deposit for the reasons already
stated. This deposit increases and the color of the brine grows darker
in proportion to the extent of the impurity in the coffee, as with
the addition of only 30 per cent. of chicory the brown color is very
marked, so that with a still larger percentage of the adulterant it
becomes correspondingly darker.