Alcoholic Beverages
Wines
Beer
Distilled
Spirits
Acknowledgement
:
N.
Shakuntala Manny
M.
Shadaksharaswamy
BEER
MANUFACTURING
Acknowledgement
:
Ret.
Prof. B.K. Mital
FST,
GBPUA&T, Pantnagar
BEVERAGES
: Many liquids or liquorous foods, such as coffee, tea, cocoa, soft drinks and
alcohol-containing drinks are considered as beverages. These contain
stimulants or flavouring agents which perform some useful functions but are
not essential for the proper functioning of the body. Soft drinks are nonalcoholic
beverages containing syrup, essences or fruit concentrate that are mixed with
water or carbonated water. The basis of all alcoholic drinks is ethyl alcohol
or simply alcohol.
Coffee
(Coffea)
Coffee
is an evergreen shrub or small tree indigenous to central Africa and Asia.
There are many species of coffee, but three species are of commercial
importance: Coffea arabica, which
supplies the largest and best quality of coffee beans, Coffea
robusta, (C. canephora)
which yields beans of lower quality and Coffea
liberica, whose beans are of still lower quality. C. arabica
is indigenous to Ethiopia and was introduced to India through Arabia. It is
cultivated in South India, mainly in the states of Karnataka, Kerala and Tamil
Nadu. It is best grown in the American tropics, where Brazil is by far the
largest producer and exporter of Arabica coffee.
Considerable
quantities of C. robusta are also produced in India because the plant
can be cultivated at a lower elevation, is longer living and disease
resistant, and the yield of coffee bean is greater than from arabica. The
robusta variety gives thick, strong decoction. C. liberica has not been
popular in India as the tea plant is susceptible to diseases and the beans
have not found favour in the market.
Production:
The world
production of coffee is estimated at 6.4 million tonnes. The Indian production
during 1997-98 was 223,000 tonnes and about 140,000 tonnes were exported
bringing in foreign exchange of Rs. 390 million dollars. Though India's export
is only about 3 per cent of the total world export; there is a good demand for
Indian coffee because of its superior quality and use in blending. India,
during 1981-82, occupied the second position in , productivity rating among
the coffee producing nations, advancing from the previous fifth position.
Coffee production is being introduced in the nontraditional areas of Andhra
Pradesh, Orissa and the North-Eastern States. The yield per hectare increased
from 609 kg in 1975 to 926.8 kg in 1998.
Coffee
flowers are white and sweet smelling, producing green berries which turn red
when ripe. The berry contains a mucilaginous pulp with two greenish grey seeds
or beans, each covered by a thin membrane, the silver skin, and both are
enclosed in a common husk-like membrane or parchament. Sometimes a single bean
fills the berry instead of two, when the seed is called a peaberry, since it
is like a pea. The berries are picked when ripe. Unripe berries give defective
beans (Triage) and overripe ones are difficult to beat to a pulp.
Processing:
Coffee processing consists of removing the skin, pulp, parchment and
silver skin. The quality of the final product depends upon the manner of
processing. Two methods are employed for processing, viz., the dry and the wet
(washed coffee process) methods. In the former method, the berries are sun
dried by spreading them out on drying floors and the coverings are removed by
hulling. The beans are later cured in curing sheds. The product obtained is
known in trade as cherry or native coffee. In the wet method, the ripe fruits
are squeezed in a pulping machine which removes the soft outer pulp, leaving a
slippery exposed layer of mucilage. The mucilage is removed by spontaneous
fermentation. This is sometimes facilitated with added enzymes. The seeds
separating from the pulp are washed and subsequently dried to a moisture
content of 12 per cent. The wet method gives better quality coffee with a
bluish-green colour (green coffee). The green seeds are then graded and
packed. Green coffee may be stored for prolonged periods with no adverse
effects.
Each
variety of coffee has its own flavour and other characteristics. Generally,
marketed coffee is a blend of different varieties of coffee beans. The blends
are controlled for flavour, aroma, colour and strength or body of the beverage
from the roasted bean.
Roasting:
Raw
or green coffee has no flavour or aroma and has an unpleasant taste. For use
as a beverage, it is roasted, powdered and brewed and the aqueous extract used
as a beverage with or without the addition of milk, sugar and other
substances. During roasting many physical and chemical changes occur. The
beans swell in size to almost double their original size, the dull-green
colour changes to brown and the characteristic coffee aroma develops. The
beans lose their hard horny structure and become brittle, with the outer
surface still smooth and firm. During roasting, pressure develops in the
beans ,and this appears to be necessary for the proper development of coffee
flavour. It is said that pressure holds the initial breakdown products
together until the proper stage of roasting is reached, when they react with
each other to produce coffee flavour. The flavour is due to a mixture of
numerous components rather than a definite chemical entity and is
apparently produced during roasting. Some moisture is lost during roasting and
carbon dioxide is produced in a comparatively large quantity, some of it
escaping and some being absorbed within the texture of the roasted bean.
Carbohydrates decompose, caramalize and, perhaps in combination with other
substances, contribute to the aroma of the beverage produced from the roasted
beans. Fatty constituents are also affected, volatile fatty acids are driven
off and complex fats and waxes are cracked to form simple ones. Proteins may
be hydrolyzed and give cleavage products. There is little change in the
caffeine content of coffee during roasting.
The
flavour of roasted coffee, to a large extent, depends upon the manner and
extent of roasting. The flavour and aroma of coffee are best. when it is
freshly roasted and deteriorate on standing. Coffee exposed to air changes
more rapidly than coffee not exposed. The staleness of coffee exposed to air
is due to the oxidative changes that take place with certain coffee constituents.
This is prevented by the presence of carbon dioxide in roasted coffee. On
storage, carbon dioxide is lost and so are the flavour and aroma. Moisture
also has a profound effect on the flavour of coffee. Coffee exposed to
moisture loses all its flavour in a relatively short time. The loss of flavour
in vacuum packed coffee or coffee packed under pressure using carbon dioxide
is less. Since the loss of flavour and aroma is more in ground coffee than in
beans, the roasted beans should be freshly ground to obtain quality coffee. In
spite of many investigations, it has not been possible to clearly understand
the many complex physical and chemical changes taking place during the
roasting of coffee beans.
Chemical
Composition of Coffee:
The constituents of coffee that are important in making a good beverage are
the flavour substances, the bitter substances, and caffeine which is
responsible for the stimulating effect of the drink.
Caffeine
is present in the coffee bean in both the free and combined states. Its
content in the bean varies in different species-C. arabica
contains
1.0-1.2; C. robusta 1.5-2.5 and C. liberica
1.4-1.6
per cent. There is a variation in the amount of caffeine in the seeds of the
same species from different parts of the world., Caffeine, in addition to
stimulation, also contributes to the bitterness of the coffee. The caffeine
content of a cup of coffee (150 ml) is about 100 mg. Most people consume three
cups of coffee a day and thus 300 mg of caffeine. While caffeine is a
stimulant, its excess use causes undesirable effects on mental and physical
health. It is as much a health hazard as alcohol and nicotine. Chronic
caffeine intoxication results in a number of symptoms (caffeinism) which
include sleep disturbance, frequent urination, muscular tension, jitteriness,
anxiety, etc. Thus, many people who like the taste of coffee but are afraid ot
adverse health effects of caffeine use decaffeinated coffee. By chemical
methods, most of the caffeine can be removed from green coffee.
Decaffeinated coffee retains most of the characteristic aroma of coffee. The
average composition of green and roasted C. arabica beans is given in Table.
Composition of green and roasted C.arabica beans (g for 100 g coffee):
|
|
|
|
|
|
|
|
|
|
|
Moisture
|
Protein
|
Fat
|
Sugar
|
Dextrose
|
Ash
|
Caffeine
|
Chlor
ogenic
acid
|
|
C.
arabica(green)
|
8.98
|
9.87
|
12.60
|
9.55
|
0.87
|
3.74
|
1.08
|
8.46
|
|
C.
arahica(roasted)
|
0.63
|
11.23
|
13.59
|
0.43
|
1.24
|
4.56
|
0.82
|
4.74
|
Source:
Wealth of India, Vol.
II, Council of Scientific and Industrial Research (CSIR), New Defhi, India,
1950, p. 299.
Several
organic acids are present in the aqueous extract from green coffee beans, the
predominant being chlorogenic acid and the least acetic acid. During roasting,
formic and acetic acid contents are increased and chlorogenic
and other acids like citric and malic are partially destroyed. The pH
of the coffee brew comes down. Acidity affects coffee flavour, the more acid
tasting the coffee, the better are its flavour and aroma. Robusta beans
produce coffee beverage that is less acid-tasting than the arabica-coffee
beverage and is generally less desirable so far as taste is concerned.
As
already indicated the flavour of roasted coffee is due to a number of
components to which the name "coffeol" has been given. More than 600
volatile compounds have been identified in roasted coffee. Low-boiling sulphur
compounds in coffee are the main flavour contributors. Chlorogenic acid
contributes to the body and astringency of the coffee beverage, and its
decomposition products contribute to the aroma of coffee. The decomposition
products of sucrose contribute much to the colour of the beverage and also to
some extent the aroma, bitterness and sourness. Protein decomposition
compounds seem to be the major precursors of coffee aroma.
Polyphenolic
substances (tannins) present in coffee contribute to the bitterness of
coffee beverage. They are readily soluble at the boiling temperature of
water. There are also present in coffee other substances, extracted on
boiling, that contribute to the bitter taste and combine with certain metallic
salts to give a metallic flavour to the beverage.
Coffee
Making:
Coffee, fresh from the roaster and ground fresh, makes a good beverage.
If it is not possible to roast coffee fresh, it is better to buy small
quantities of the powder and keep it covered to exclude air and moisture. The
beverage is at its best when freshly brewed. If it is cooled and reheated, it
become bitter and unpleasant.
Coffee
is ground and marketed to meet a range of brewing methods. The basic grinds
are fine, medium and coarse. A variation can be found within each of these
categories. Fine grind is used in vacuum coffee makes; medium or drip grind is
used for making coffee in a drip pot or by steeping; and coarse grind is used
in a percolater. It is always best to match the grind to the coffee making
equipment to obtain a good quality beverage.
Preparation
of coffee beverage of high quality requires that the extraction of
caffeine and flavouring materials be maximum and that of tannin minimum.
Different methods are used to obtain this object. The methods differ in the
type of utensils used and the ground coffee, but they are all based on the
principle of bringing ground coffee in contact with hot water to extract the
soluble constituents. Whatever the method employed, the vessels used to
prepare coffee must be very clean. The material used for coffee making is
important. Some metals influence the flavour of the beverage. Stainless steel,
glassware and enamelware are preferred. Water used in coffee making should be
soft or of low hardness. A temperature between 8S° and 9S°C is optimum for
preparing coffee. If the water is heated to boiling point, it over-extracts
soluble solids and the beverage is bitter, and there is also a loss of flavour
substances. However, pouring boiling water on the coffee powder is
permissible, as the temperature drops as soon as the water comes in contact
with the grind.
Vacuum
coffee: Vacuum
coffee is made in a two-part container. The upper compartment holding the
coffee has an open tube that extends to the bottom of the lower compartment
containing water. By heating water in the lower compartment, sufficient
pressure is created in the bottom container to force water through the coffee
grind into the upper compartment. When the water and grounds are in contact
for about 3 min, the heat is reduced on the lower compartment resulting in a
reduced pressure and the brewed coffee is pulled down to the bottom
compartment. Powdered coffee is usually prevented from pouring into the
lower compartment by the use of cloth covered disk, held in place over the
tube opening. The advantage of vacuum coffee is its convenient preparation;
its disadvantage is that the coffee prepared thus is slightly bitter because
the water and grounds are in contact for a few minutes at a high temperature.
Drip
coffee:
Drip coffee is made in a dripolator (coffee filter) consisting of an
upper compartment which is perforated and a lower compartment which receives
the filtered coffee. The perforation of the upper compartment is covered with
a thin cheese cloth or a perforated disc with a stem, to prevent the passage
of the grind into the beverage. Drip grind coffee is placed in the upper
compartment and boiled water poured into the compartment. The water drips or
flows through coffee into the lower compartment. The drip method is easy and
is used by a majority of persons. This method extracts less of the bitter
substances and retains more flavour constituents than other methods.
Percolator
coffee: Percolator
coffee is made by placing coarse ground coffee in a basket suspended in a stem
near the top of the percolator and is inserted into the percolator. Cold water
is placed in the lower part of the percolator and heated. The heated water is
forced up the tube of the percolator and sprays on the grounds, extracting
the soluble materials. The usual percolation time is 6 to 8 min. Percolator
coffee is likely to be somewhat bitter because very hot water goes through the
grounds several times. Also, the constant aeration of the, brew as
the liquid is forced up and sprayed over the grounds results in the loss of
flavour.
Steeped
coffee:
This
coffee (misnamed as boiled coffee) is made by heating water and medium
ground coffee, without allowing it to boil. If coffee is boiled it becomes
bitter. Steeping time is about 6-8 min. During steeping, the coffeepot should
be lightly covered to prevent loss of volatile flavouring compounds. The
coffee is then passed through a strainer. This method of making coffee is
convenient, since no special equipment is required. If care is taken not to
boil it, the beverage will have goad aroma, desirable flavour and will not be
bitter.
Espresso
coffee: This
is made by a special machine which brews the beverage a cup at a time. It is
derived from brewing finely ground coffee with a mixture of steam and hot
water.
Iced
coffee:
This is made by pouring a freshly made strong coffee infusion over
crushed ice. The infusion is obtained by using more of coffee grounds per cup.
This offsets the dilution that takes place as the ice melts in the hot
beverage, resulting in a pleasing beverage with a distinctive flavour. .
Soluble
Coffee: Soluble
coffee is a dry, powdered, water-soluble solid made from very strong coffee
brew. It is marketed as "instant" and "freeze-dried"
coffee. Instant coffee is made by the vacuum spray drying of the brew from the
ground coffee, obtained from the percolation method. Freeze-dried coffee is
made by first freezing the strong brewed coffee and then drying by
vaporization in vacuum. Instant coffee has a flavour similar to freshly brewed
coffee but lacks the aroma of the fresh beverage. Attempts are being made to
improve aroma by using additives. Freeze-dried coffee is being obtained in
granulated form, the particle size being roughly that of ground coffee.
Attempts to recover the volatile aromatic substances lost during the
processing of the coffee brew and adding them to freezedried coffee to
obtain a product with an aroma similar to that of freshly brewed coffee have
been successful. Though India is producing and exporting instant coffee, we
have not yet made freeze-dried and granulated coffee. The world export of
soluble coffee amounts to around 300,000 tonnes of green coffee equivalent.
Chicory
(Cichorium intybus) is a
well-known substitute for coffee, often used blended (up to 50 per cent) with
the latter, in liquid coffee extracts. It gives a bitterness to the beverage,
which some people find refreshing. The part of the plant used is the root
which is chopped, roasted and ground.
Tea
(Camellia sinensis)
Camellia
is an evergreen shrub or tree, which grows wild from India to China. There are
about 45 species of Camellia of which Camellia sinensis,
considered native to India; is the important one from which tea of
commerce is made. Commercial tea is obtained from plants propagated by seed
sown in a nursery; cuttings can also be rooted. Trees for plucking are
regularly pruned to obtain a bush shape, which encourages maximum leaf production.
Amongst cultivated C. sinensis
there are two types: `China' and
`Indian'. The former type is a slow-growing smaller tree with narrow leaves,
while the latter is fast growing with large drooping leaves. The yield from
Indian types is higher than that of the China type. The important tea growing
countries are India, China, Sri Lanka, Japan and Kenya.
Tea
leaves are usually plucked by hand. The average interval between pluckings is
about a week. In India, about 5-6 pluckings
are made in a season. Usually, the terminal bud and two terminal leaves from
the end of each shoot are plucked. In some cases, the bud and three leaves are
taken giving a higher yield and a poorer quality product. Some of the best
teas come from high-altitude areas, such as Darjeeling, while teas from the
plains are often of `common' quality. The yield at high elevation is poor
compared to that at lower elevation for the same kind of plant. .
Production:
In India, the two main tea-growing regions are the hilly districts of
Assam and West Bengal, and the Western Ghats of Kerala, Tamil Nadu and
Karnataka. India tops the list in production and export of tea, in the world.
In 1998, the world production of tea was 2.96
million tonnes of which India's
share was 0.87 million tonnes. Of the total world export of about 1.13
million tonnes during that year,
India exported 203,000 tonnes valued at Rs.
990 crore. The tea exported from India is mostly black tea and the export of
green tea is small. However, large quantities of tea waste and fluff (pieces
of leaves, leaf hair, fibre, etc.) are exported and used for the manufacture
of caffeine. India has also been exporting consumer tea packets instead of
bulk tea chests and instant tea.
Processing:
Commercial tea is available mainly in three forms black tea, green tea and
oolong tea. The three forms of tea differ only in the method of processing the
leaves. Black tea is by far the most popular among the three.
Black
tea:
The
various processing steps in the manufacture of black tea are withering,
rolling, fermentation, drying, grading and packing. Withering is carried out
by spreading tea leaves thinly on racks or shelves, to dry the leaves
partially. Generally withering is allowed till the water-content in the leaf
is lowered by about 40 per cent. The withered leaves are then rolled to break
open the cells and release the juices and enzymes. Various rolling techniques
are employed and the flavour characteristics inherent in various teas
partially depend on the technique used. After rolling, the leaves are shifted
and spread out thinly on suitable platforms and allowed to ferment for 2-6
hours at temperatures between 21° to 27°C. During this process, the enzymes
bring about the oxidation of the various polyphenols present in the juices,
resulting in the change of colour from green to reddish copper. Two of the
important polyphenols that undergo oxidative changes are catechin and
gallocatechin.
When
the fermentation has proceeded to the desired degree, further change
is arrested by drying or firing. This comprises the passing of the fermented
leaves through a chamber in which hot air is circulating,; At the entrance of
the chamber, the temperature is 93°C which drops to about 49°C
near the exit. The time required for this process is about 3U-40 minutes and
the dried product contains 3-4 per cent moisture. Besides halting the fermentation
process, firing causes some caramelization to occur resulting in the
characteristic colour of black tea leaves.
.
The
aroma of tea is believed to develop during the fermentation and firing
processes. Although a large number of volatile compounds have been identified
from tea leaves, none has -been found to make any significant contribution to
the tea aroma.
The
dried product is cleaned and sorted into various grades of tea of commerce.
The quality of black tea is related to the polyphenol and enzyme content of
the leaves used in processing. They are maximum in the buds and the first and
the second leaves (28, 28 and 27 per cent respectively) and teas obtained from
these are the most desirable. On this basis, tea is categorized as "leaf'
grade and 'broken' grade. The broken grade comprises the smaller : sizes
sifted from bulk or those obtained by cutting the longer leaf grades to
desirable sizes. Both leaf grade and broken grade are further categorized as
orange pekoe, pekoe and souchang. Orange pekoe and pekoe refer to the size of
the leaf only. Orange pekoe has the largest leaves, followed by pekoe and
souchang in decreasing order. Orange pekoe is perhaps the best quality.
Other
things being equal, the broken grades usually give a stronger tea than leaf
grade. Besides the above grade, there are the waste products Fannings and
Dustings.
Tea
is generally blended before it reaches the consumer. In India, the blended tea
is packed in plywood boxes lined with aluminium foil and parchment paper.
During packing, tea absorbs moisture. If the moisture content increases to 6-7
per cent, tea is to be subjected to a second firing before packing. India is
also exporting tea in consumer tea packs instead of bulk tea chests.
Green
tea:
Green
tea is made in the same manner as black tea, but the withering and
fermentation steps are omitted. The leaves are heat treated, rolled and dried.
The heat treatment consists of pan-firing or steaming to inactivate the
enzymes. The aroma, flavour and colour of green tea are significantly
different from those of black tea. Green tea is a light, yellowgreen
beverage when brewed correctly. The Japanese mainly produce and consume green
tea.
Oolong
tea:
Oolong
tea is an intermediate between black and green tea in colour and taste
characteristics. Its production method is
similar
to that employed for green tea, except that the leaf is slightly withered and
light fermentation allowed before the leaf is dried.
Composition
of Tea: The
important constituents of tea contributing to the flavour of tea beverage are
caffeine, polyphenols and essetial oils. Analysis of fresh leaves of Indian
tea gives the following values: Polyphenols, 22.2; protein, 17.2; caffeine,
4.3; crude fibre, 27.0; starch, 0.5 and ash, 5.6 per cent. Fresh tea leaf also
contains carotenes, B -vitamins and ascorbic acid. During the manufacturing of
black tea, ascorbic acid is lost.
The
maximum amount of caffeine is present in the bud and the first two leaves.
Small quantities of compounds related to caffeine, viz., theophylline,
theobromine, xanthine and hypoxanthine are also present.
The
important polyphenols present in tea leaves are catechins and gallocatechins.
These undergo changes during fermentation in black tea manufacture. Enzymes
involved in fermentation are polyphenol oxidases.
No
change takes place in green tea as its manufacture does not involve
fermentation. During fermentation, polyphenols undergo oxidation and the
oxidized products polymerize and part of them combine with caffeine. The
caffeine-polyphenol complexes are soluble only in hot water and this accounts
for the 'creaming' observed when hot tea infusions are cooled.
Tea
leaves contain a volatile oil consisting of alcohols, aldehydes, phenols and
some fatty acids. On steam distillation, black tea gives an essential oil. The
characteristic aroma and flavour of tea is due to the essential oil.
Tea,
like coffee, has no nutritive value. The proteins present in tea leaves are
rendered insoluble in the processing. Tea infusion contains negligible
quantities of carbohydrates and fat. Whatever nutritive value tea has comes
from added milk and sugar. Tea as a beverage is consumed mainly for its
stimulating value.
Preparation
of Tea:
A good cup of tea will be sparklingly clear and not have a surface
film. It should have maximum flavour with minimum polyphenoi compounds which
contribute to bitterness. In order to obtain this, the water used in making
tea should be fresh and soft. If water is hard, the dissolved salts form an
undesirable precipitate with polyphenols and this will be present as an
unattractive film that floats on the surface of tea. The water should be
freshly boiled but still contain sufficient oxygen to give the tea a fresh and
pleasant odour. Metallic teapots impart a metallic flavour. It is best to use
china, glass or enamelled ware. Water heated to 85°C to boiling should be
added to the appropriate amount of tea (generally one teaspoonful for 150 ml
contained in the pot). The pot should be covered with a lid which helps retain
the heat and prevents the escape of volatile compounds. Flavour substances and
caffeine are readily extracted by: short infusion periods. Generally, a
steeping period of about 3 min gives a stimulating, but not astringent,
beverage.
A
very convenient method of making tea is by -the tea-ball or bag
method. In this method, water at the boiling -temperature is poured
over tea contained in a cheese cloth or paper bag or a silver ball. The bag
or ball is allowed to remain in contact with water till-the desired
strength is obtained. Milk or lemon may be added to the tea infusion-for
body and flavour, and sugar for taste.
Iced
tea: Iced
tea is popular in some countries. Hot tea is prepared in the usual way by
using twice as much tea leaves. The hot tea-is thoroughly chilled
before pouring it over ice. It may also be poured over ice while it is still
hot. This will result in a beverage which dilute to normal strength as ice
melts. Cloudiness is generally a problem with iced tea, as tannins precipitate
when tea cools.
Instant
Tea: Instant tea
(soluble tea) products have become popular in recent times. These products
are hot and cold water solubles, iced tea concentrates, carbonated tea, etc.
In the preparation of hot water soluble instant tea, the fermented tea leaves
are extracted with hot water, centrifuged and dried in drum drier or freeze
drier. For the manufacture of cold water soluble tea, the aqueous extract is
cooled to 5°C, the separated caffeine-polyphenol compound is removed by
centrifugation and then dried. Iced tea concentrate is cold water soluble and
contains sugar, citric acid and essences. Ready tea is instant tea with sugar
and milk powder. India produces all these varieties of instant tea and
sizeable quantities are exported. The export in 1980-S1 was 10.76 million kg.
Instant
tea is largely used in making iced tea because of its solubility in cold
water. However, the flavour and aroma of instant tea is less full than that of
the beverage freshly prepared from tea leaves.
Cocoa
(Theobroma cocoa)
Cocoa
plant is a small tree native to the American tropics. It is now grown in all
tropical regions of the world. The chief cocoa-producing countries of the
world are Ghana, Nigeria, Ivory Coast and Brazil. Cocoa was introduced to
India from Sri Lanka and is a comparatively new crop. Its production is fast
picking up and it is grown in Kerala, Karnataka and, to some extent, in Tamil
Nadu.
Cocoa
tree has the unusual habit, like the jackfruit tree, of bearing its flowers
and, subsequently, its pods on the main trunk as well as on the branches.
Cocoa pods, when mature, are yellow in some varieties and red in others. The
pods are 10 to 18 cm in diameter, having thick leathery rinds containing 20-50
beans inside in rows. The seeds are embedded in white or pinkish pulp. Seeds
are the principal source of cocoa or
cocoa powder highly prized as a nutritious beverage, and chocolate used as
food all the world over.
Production: The
world production of cocoa is of the order of 2.9 million tonnes. India's
output in 1997-98 was only 6,000 tonnes. The demand for cocoa products till
recently was mainly met by imports. We have been importing about 1,000 tonnes
of cocoa bean a year and some of the imported cocoa is re-exported as cocoa
powder, chocolates, cocoa butter, etc. We are becoming self-sufficient and are
at the stage of discontinuing imports.
Processing:
Cocoa pods, after
harvesting, are cautiously opened. The beans and mucilage are scooped out and
subjected to natural fermentation either in heaps, wooden boxes (sweat boxes)
or baskets. Fermentation generally takes five to ten days. At the end of
fermentation, the pulp breaks down and there is a change in the colour of the
seeds from pale yellow or violet to brown. The endogenous enzymes, activated
by the heat of fermentation, bring about changes in proteins and polyphenols
in the kernel and there is also a reduction in the astringency of the kernel.
The beans are then dried to six to eight per cent moisture level in sun or in
artificial dryers. The bean is then ready for export or further processing to
manufacture cocoa products.
The
dried beans are cleaned, sorted and roasted. Roasting develops the
characteristic flavour. Although a large number of compounds have been
identified in cocoa and chocolate, no single constituent is found responsible
for the characteristic subtle aroma. Roasting also causes changes in the
chemical structure of polyphenols, producing less astringent compounds. While
roasting, the beans are passed through corrugated rollers to break their
shells and removed by winnowing. The cotyledons are known as 'nibs'. Usually
there is some blending of the nibs from different varieties of cocoa before
they are processed further.
The
nibs are used for the manufacture of cocoa and chocolate. The nibs are ground
using stone mills or other suitable mills to a fine paste or liquor. The heat
produced during grinding causes cocoa fat to melt and the melted fat carries
with it, in suspension, finely ground particles of cocoa. This is known as
"cocoa mass", "chocolate liquor" or "bitter
chocolate". This mass solidifies at about 30°C.
Cocoa
mass is very rich (50-55 per cent) in fat and cannot be used directly for the
preparation of any beverage. It is subjected to filter-pressing to separate
out a major part of fat (cocoa butter). The amount of fat left in the pressed
cake can be varied by the conditions of pressing. The pressed cake is used for
producing cocoa powder. The fat-content of cocoa used- for beverage is fixed
by law. According to Indian Standards Institution (ISI) specifications,
cocoa used for beverage should contain 20 per cent cocoa fat. Medium-fat
cocoa, containing between 10 and 20 per cent fat and. low-fat cocoa,
containing less than 10 per cent fat are made. Flavouring substances like
vanilla and cinnamon are generally incorporated into cocoa powder.
The
pressed cake, after the removal of cocoa butter, contains 1.8-1.13 per cent
free acids. In one of the methods of cocoa processing the acid is neutralized
with the addition of a requisite amount of alkali. This is known as the
"Dutch process", because it originated in Holland. Cocoa processed
by this method is dark in colour and the flavour will be somewhat more bitter
and astringent than the same material not treated with alkali.
Chocolate:
Cocoa mass not treated with alkali is generally used for the
manufacture of chocolate. There are many types of chocolate depending upon the
level of cocoa mass, added cocoa butter, sugar, milk and other ingredients.
Plain chocolate (sweet chocolate) is cocoa mass processed with cocoa butter
and sugar. Milk chocolate contains, in addition to these ingredients of
plain chocolate. milk solids. Plain chocolate contains 44-55 per
cent
sugar and 32-42 fat, while milk chocolate contains 35--55 per cent sugar,
28-39 per cent fat and 12 per cent milk solids. Plain and milk chocolate are
extensively used in confectionery and ice cream.
Composition:
The analysis of
cocoa beans (processed) gives the following values: moisture 2.13; fat, 54.68;
total nitrogen, 2.16; starch, 6.14; pentosesans, 11.19 and tannins 6.15 per
cent. The total nitrogen includes that of protein, theobromine and related
alkaloids. The theobromine content of cocoa is hgh (about 2.8 per cent). Cocoa
is the natural source of theobromine. There is some loss of theobromine
content during fermentation and roasting. Cocoa also contains caffeine (about
0.6 per cent). The proteins of cocoa bean are present in combination with
polyphenols. Unlike coffee and tea, which are strained forms of beverage,
cocoa and chocolate remain in the beverage and contribute to the nutritive
value of the beverage. Because of their high content of fat, cocoa products
are good source of energy. Milk, a usual constituent of cocoa and chocolate
drink, adds to the nutritive value of the beverage. The theobromine and
caffeine contribute to the stimulating effect of the beverage.
Cocoa
butter:
Cocoa butter
which accounts for more than 50 per cent of cocoa bean is a valuable byproduct
of the cocoa industry. The world trade in 1979 in cocoa butter was of the
order of 175,000 tonnes. The butter is mostly used in the manufacture of
chocolate.
The
butter is a pale yellow liquid with a characteristic odour and flavour of
chocolate. It is brittle at temperatures below 25°C, softens in the hand and
melts (34°C) in the mouth. It is not greasy to touch. It is rich in saturated
fatty acids (palmitic and lower acids 26.21, stearic and higher acids 34.4 per
cent). Oleic and linoleic acids are present to the extent of 37.3 and 2.1 per
cent respectively. The butter keeps well due to
the presence of fat-soluble antioxidants in it.
Cocoa
Beverages: Cocoa
and chocolate, apart from their many uses in cooking; find extensive use in
the preparation of beverages. When chocolate is used, it sticks to the
container and gets scorched when heated. This can be eliminated by heating
chocolate over hot water or by heating it at a low temperature. The melted
chocolate is then blended with other ingredients. Owing to its high starch
content, cocoa will lump if put directly into a hot liquid. It should be mixed
with a small amount of cold liquid before-being combined with other
ingredients. Cocoa and chocolate thus treated are heated to boiling and held at
that temperature for sometime to gelatinize the starch. This gives body
and flavour to the beverage and reduces the amount of sediment that settles
from either of the beverages.
Apart
from coffee, tea and cocoa, a number of preparations are available in the
market such as Ovaltine, Bournvita, Boost etc., which are consumed as hot
drinks. While the former group of beverages are stimulants the latter are
energy foods and are consumed as supplementary foods to regular diet. They.
contain mainly malted cereals, creamy milk, sugar and artificial
flavour, and sometimes are
fortified with nutrients and minerals. Some preparations also contain cocoa.
The drink is prepared by stirring the material in warm water or milk and is
generally consumed as hot drink; but could also be used as a cold drink.
Soft
Drinks
Soft
drinks constitute one of the largest food industries in the world today.
Tremendous advances have taken place in process technology in the soft drink
industry in the past one or two decades.
In
India, in the organized sector alone, annual production of soft beverage is
about 45 million cases. The flavoured component of most of the well-known
brands of soft drinks is a well-guarded secret. The most popular soft drinks
sold throughout the world today are `cola' (an extract from the tree cola),
orange, root beer, ginger, lemon and lime. Most of the cold drinks sold in the
country belong to this class.
Soft
drinks are divided into three classes: the carbonated, fruit flavoured (still)
and sparkling (soda water). The carbonated beverages, in turn, are divided
into two groups, those with artificial flavour and those with natural fruit
juice.
Ingredients:
The major ingredients of soft drinks are:
(i)
sugar and sugar substitutes
(ii)
flavour emulsion and cloudifiers
(iii)
colouring agents
(iv)
acids and preservatives
(v)
water
(vi)
carbon dioxide
A
quality soft drink should have a balanced blend of flavour at the proper
intensity leaving a clean mouth taste with no lingering flavour or unpleasant
after taste and should have proper carbonation to impart zest and sparkle to
the drink.
The
process of manufacturing carbonated beverages consists of several steps. Syrup
is prepared from sugar or substitutes and water. To the syrup, acids, colour
and flavouring agents are added as required. The components are blended. A
suitable aliquot of the mixture is diluted with chilled carbonated water and
bottled. Alternatively, ready syrup is diluted, chilled, carbonated and then
filled in the bottle. The bottles are then capped, labelled and marketed.
Sugars:
Sugar and sugar substitutes contribute the sweetness necessary to
balance the various ingredients, give body and mouth feel and also act as
carriers to distribute the flavour components uniformly throughout the drink.
Sugar component also contributes to the food value of the beverage and, to
some extent, to the flavour. Sucrose is the most widely used sweetening agent.
Some sweetening agents like cyclamates which were being used formerly are now
banned as they are found to be harmful. Because of the high cost of
crystalline sugar, sugar syrups are used as sweeteners. Fructose syrup
(processed from corn starch) or high fructose corn syrup (HFCS) are used these
days. 55 per cent fructose corn syrup has approximately the same sweetness as
sucrose, while 90 per cent fructose syrup is approximately 50 per
cent more sweet than sucrose. Use of fructose syrup in soft drink manufacture
has other advantages; it permits substantial reduction in calorie content of
the drink and it also reduces the cost of the drink. Fructose syrup is not yet
available in India.
Flavouring
materials:
Three
types of flavouring materials ate used in soft drinks: those obtained from
natural sources, such as fruit concentrates or extracts from natural flavour
materials; synthetic compounds identical to those obtained from natural
products; and synthetic chemicals not found in nature. Most flavours, however,
are wholly natural or a blend of natural and synthetic materials identical to
those found in nature. The flavouring agents should have complete solubility,
compatibility, clean mouthfeel without an after taste, resistant to acid and
heat, and stable to light. Flavours are used generally emulsified in vegetable
gums. This prevents the flavour substances (particularly oils) from separating
out in the beverages.
Colouring
materials: These
are used in soft drinks in order to maintain a uniform colour in the beverage
from batch to batch. In some cases colour is derived from flavouring
substances used. Generally, synthetic food colours and natural colouring
ingredients like caramel are used. Caramel in beverages gives them
a dark to light brown colour and is usually associated with flavour of the
type derived from roots, leaves, herbs and berries.
Acids
and preservatives: Acids,
in addition to taste, enhance the flavour of soft drinks. The acid most widely
used is citric acid. Other acids used in considerable quantities are tartaric
and phosphoric acids. Lactic and
Malic acids are also used in lesser amounts. Citric acid (present in citrus
fruits) adopts itself well to nearly all light and fruity flavours. Phosphoric
acid is used in beverages with leaf, root, nut or herbal flavours. Tartaric
acid (present in grapes) is used in grape flavours.
The
acids, besides giving taste and flavour, also act as mild preservatives.
However, to ensure against spoilage, sodium benzoate is commonly used as a
preservative.
Water:
Water
constitutes the largest (about 92 per cent) component of soft drinks. Water
used in beverage manufacture must be free from suspended matter and colouring
matter. It should not contain minerals which would interfere with the flavour
and colour of the beverage. It should also be free from objectionable odours.
Thus, water used should conform to the specification set for beverages.
Carbon
dioxide: Carbon
dioxide is an important constituent of soft drinks. The gas used must be
absolutely pure. It enhances the flavour of the beverage and gives it its
sparkle. It also extends the life of the drink. The level of carbonation is
determined by the flavour component and quality of flavour.
Carbonated
beverages are mostly packaged in bottles. In some countries they are also
packed in cans with a pull ring top. Besides glass bottles and cans, plastic
containers (polyethylene terephthalate, PET) are coming into use. Glass
bottles are covered with crown lined with PVC or cork. In recent times, glass
containers are being covered with a foil lid.
Fruit
Beverages
There
has been a considerable increase in the consumption of fruit and vegetable
juices in the world during the last few years and there are possibilities of
its further increase. The export of fruit juices from developing countries has
more than doubled during the period 1977-82. India exported Rs.10 crore worth
of fruit juices in 1982.
The
beverage industry is by far the largest outlet for fruit juice and
concentrates absorbing over 80 per cent of production. In India a little over
60 per cent of the fruit produced is used in fruit based beverages. Many
different types of beverages, such as fruit juices, fruit drinks, squashes,
cardials and fruit punches, are available. They are broadly defined as
follows:
Fruit
juice: This
is a natural juice pressed out of a fruit. This is unaltered in its
composition during preparation and preservation.
Fruit
drink: This
is made by liquefying the whole fruit and at least 10 per cent of the volume
of undiluted drink must be whole fruit. It may be diluted before being served.
Fruit
squash: This
consists essentially of strained juice containing moderate quantities of fruit
pulp to which sugar is added for sweetening, e.g., orange squash, lemon
squash, mango squash, etc.
Fruit
cordial: This is
fruit squash from which all suspended material is completely eliminated and is
perfectly clear, e.g., lime juice cordial.
Fruit
punches: These
are made by mixing the desired fruit juices at the time when it is served.
Fruit
juice concentrate: This
is fruit juice which has been concentrated by the removal of water either by
heat or by freezing.
Sherbats: This
is a cooling drink of sweetened diluted fruit juice.
Fruit
juices are valuable from the nutritional point of view; they are rich in
minerals, vitamins and other nutritive factors. Besides, fruit juices are
delicious and have a universal appeal, In developed countries fruit juices
commonly form part of the breakfast and are produced in very large quantities.
(In the USA, the annual production of juices is more than 50 crore kilo litres.)
Fruit juices do not form the normal diet in our country and the fruit juice
industry is in its infancy in India. Preparation of the juice is limited
mostly to home scale production. The fruits generally used for making juice
are orange, grape, apple, pomegranate, melon, mango, etc. Of late, the
manufacture of squashes on a commercial scale has made some progress.
Fruit
juices are best in taste, aroma and colour, when freshly expressed. The most
important problem, therefore, in the fruit juice industry is to use such
methods as would help retain these properties to the maximum extent. The steps
involved in the processing of juice are selection of fruit, extraction of
juice, deaeration, straining and preservation.
Freshly
picked, sound and suitable varieties of fruits are selected and thoroughly
washed. The juice is extracted by crushing and pressing the fruits;
while extracting the fruit juice, fruit components other than sacs or cells in
which juice is present are to be avoided as far as possible. Further; the
juice should not be unduly exposed to air. The juice (particularly pure orange
juice, which is susceptible to the action of air) is immediately deaerated by
subjecting it to a high vacuum. Afte, deaeration, the vacuum is released with
nitrogen gas, the juice is transferred into containers which are hermitically
sealed and frozen. Fruit juices-in sealed containers keep well for
about 2 years in the frozen condition. In the alternative, the fruit juice is
spray dried.
When
clear juice is required, the juice is strained and complete removal of all
suspension is effected by filtration and clarification. Clarification needs
the removal of colloidal suspensions of the fruit juice. This can be brought
about by freezing, heating, use of enzymes or of finning agents. The finning
agents produce a voluminous flocculant precipitate which gradually settles,
carrying down with it colloidal suspensions. The clarified juice, as in the
case of whole fruit juice, is preserved by freezing, pasteurization or the
addition of chemical preservatives, such as sodium benzoate or bisulphite.
Alcoholic Beverages
Alcoholic
beverages have been known since antiquity. These are judged in terms of
flavour and stimulant effect and hardly at all as sources of calories.
However, the calorific value of alcohol in 7 Kcal/g and excess of alcohol
consumed could add to the total calorie intake of a person. In the case of
distilled liquors (whisky, brandy, gin and rum), the calorific value is only
due to alcohol and consu ption of 10(l ml of these, beverages would yield
about 230 Kcal of energy and wine contain some nutrients present in the
original malted barley and the fruit juice used in their preparation and
naturally their energy value would be higher than that of distilled liquors;
350 ml of beer gives about 150 Kcal and 100 ml of wine about 80 Kcal.
Alcohol is absorbed without
prior digestion but the body has limited capacity to oxidize it. That is the
reason why alcoholic beverages are to be sipped instead of gulping them. As a
drug the effects of alcohol vary from mild stimulation, when small amounts are
consumed, to loss of coordination and even death when large amounts are
consumed.
There
are three main classes of alcoholic beverages-wines, malted beverages (beer)
and distilled liquors. Different starting materials and different methods are
used in their manufacture. But there is one common characteristic in all of
them, namely, they are made by the process of fermentation. The essential step
in all the fermentation processes is the conversion of glucose into alcohol by
yeast.. The enzymes present in yeast catalyze the breakdown of glucose.
Yeast enzymes
C6H1206 -------------------------------->
2C2H5 OH + 2C02
Wines:
Wine is the oldest of the alcoholic beverages made by the fermentation
of grape juice. Wine, strictly speaking, is a product of vine, but often
includes all fermented liquors obtained from different fruit juices
(fruit wines). Wines differ greatly in their character, because grapes grown
in different regions differ in their composition, particularly with respect to
their volatile components which contribute to flavour and bouquet and in the
method used for wine making.
There
are different varieties of wines and in many cases they are named by reference
to their place of origin, e.g., champagne is produced in the district of
Champagne in France. Most of the wines produced in the world are natural
and still (without excess of carbon dioxide). Sparkling wines, such as
champagne, contain excess of carbon dioxide due to the secondary fermentation
that occurs after bottling. The carbon dioxide generated is stored within the
liquid under its own pressure and gives the wine a 'sparkle'. Some wines like
port and sherry are fortified wines
and differ from natural wines in
that some alcohol (grape brandy) is added to them before the completion of
fermentation. Vermouth is also a fortified wine prepared by
the addition of spice mixtures or their extracts at various stages
during fermentation.
Wines
also differ in their colours. The colour of wine may be white or red. However,
the colour does not depend on the colour of the grapes from which it is made;
in fact, white wines may easily be made from black grapes by using only the
juice. In making red wines both juice and skin are used; the pigment giving
colour to the grapes lies just under the skin and is extracted from it during
fermentation. Wines may be either 'dry' or 'sweet' depending upon the extent
to which the fermentation has taken place. If fermentation has taken place
until all the sugars are used up, the resulting wine will be dry, whereas if
it is stopped while some sugar
remains, it will be sweet. Yeast cannot tolerate an alcohol content greater
than 16 per cent. Most of the natural wines contain 8--10 per cent alcohol.
Fortified wines contain about 20 per cent alcohol, which is sufficiently high
to kill the microorganism that attack natural wines. Wines containing less
than 14 per cent alcohol are table wines while
those which contain more are dessert wines.
In
the manufacture of wine, grapes are picked at the proper time when the sugar
and acid contents are in the right proportion. The composition of the grapes
varies according to the climatic conditions prevailing during their
cultivation and thus the quality of wine varies from one year to another.
Therefore, there is the practice of 'vintage dating' the wine with the year of
the crop from which it is made. Immediately after picking, in the case of red
wines, the grapes are crushed and the juice together with he skin, pulp and
seeds are transferred to the fermentors. After fermentation is completed, the
fermented juice is pressed out. In the case of
white wines, pressing takes place
before fermentation.
'Wild'
yeast and other microorganisms are
present on the skin of the grapes and these pass into the juicy pulp (known as
must) when the fruit is crushed. These are destroyed by adding sulphur
dioxide (or potassium metabisulphite) in the required quantity. If the sugar
content is low, sucrose is added to the desired strength and the pH is
adjusted to 3.2-3.4 by the addition of tartaric acid. Next, the must is
inoculated with a pure culture of
actively growing yeast (Saccharomyces
ellipsoideus). The temperature and duration of fermentation depend
upon whether dry or sweet wine is required. Fermentation usually lasts 4 to 10
days.
When
fermentation is complete, the clear wine is syphoned from the yeast sediment
into barrels (raking) and the wine allowed to age. During this period
secondary fermentation takes place and the wine also loses
its raw and harsh flavour and mellows down. During this period of
maturation clarification takes place in the natural way.
It can also be achieved by finning and filtration. Next, the wine is
bottledand allowed to mature; the time of this maturation extends to a number
of years depending upon the quality desired.
Wines
are also made from juices of other fruits and berries. Cider is fermented
apple juice. The method of fermentation with fruit juices other than of grapes
is almost similar to that of preparation of grape wine.
Beer:
Beer, next to wine,
is the oldest alcoholic beverage to have been made. There is evidence to show
that fermented beverage from barley existed in Indus Valley civilization about
5,000 years ago and in China, Egypt and other cultures even earlier. The first
brewery in India was started in 1860; in 2000, there are 55 breweries and the
beer production is about 50.7 million hectolitres, which is very insignificant
compared with a world production of 120 billion hectolitres in the same year.
It is projected that world consumption will be 180 billion litres in
2001-2010. The chief beer producing countries in the world are USA, FDR or
Germany, USSR, UK and Japan.
The
term beer is normally applied to a beverage made by the fermentation of barley
malt. However, terms like ale, stout, lager and porter are also used for beer,
the difference between them being the method of production. The materials used
in the manufacture of beer are barley, malt, cereal adjunct, hops,
water and yeast. The principal operations involved in the production of beer
are malting, mashing and fermentation.
The
starting material for the production of beer is bareley malt.
Starchy
materials that are cheaper than malt are used as 'adjuncts' to replace some
malt. The most commonly used cereal adjunct is maize in the form of grits or
flakes. Other adjuncts suitable for brewing are broken rice, wheat, raw
barely, tapioca, starch and sorghum. Such adjuncts should not impede
the fermentation process or have an undesirable effect on the quality of the
product. The entire starch of the adjunct is to be converted into sugar. Thus,
the percentage of adjunct that can be added is restricted by the amount of
enzymes in the malt. The introduction of microbial enzymes has increased the
flexibility of varying adjunct proportion, as these enzymes supplement malt
enzymes. They also reduce the cost of raw material and maintain the quality of
beer. Liquid syrup adjuncts can also be used, but they are yet to enter the
brewing field in India.
Hop
(Humulus lupulus) is a
vine native to Europe and ' Western Asia. During the early 1970s, hop growing
has been introduced to Kashmir and successfully cultivated. Varieties
grown in Kashmir have satisfactory brewing quality regarding bitterness but
are low in flavour. From about the 15th century, beer is being flavoured with
hop. The part used in brewing is the female 'cone' consisting of a cluster of
pale, yellowish green bracts and bracteoles enclosing the flowers and later
the fruits. Hop contains essential oils and resins which impart the
characteristic bitter flavour and pleasant aroma to beer. It also destroys the
enzymes and helps sterilize the brew before fermentation.
Suitability
of water for brewing is of great importance in beer making. Water should be
hard; if soft, salts are added to the required hardness. If the water is too
hard, it may have to be boiled to remove most of the temporary hardness.
The
yeast used depends upon the type of beer to be manufactured. For the
production of ale, "top fermentation" systems are used with the
yeast Saccharomyces cerevisiae. In
top fermentation, the yeast is carried to the top of the fermentating vats by
rapidly evolving bubbles of carbon dioxide. For the production of lager, the
"bottom fermentation" system is employed with Saccharomyces
carlsbergensis. During fermenlation, the yeast settles at the
bottom of the vats.
In
the manufacture of beer, the malt is 'mashed', i.e., the ground malt is
steeped in hot water in vessels called mash tun. Two mashing methods are
generally employed: infusion mashing, followed in India, and decoction
mashing. In infusion mashing, hot water at 65.5°C is mixed with ground malt
to the consistency of porridge. Cereal adjuncts (gelatinized) are added to the
malt grit. Sugar syrups, if desired, are also added at this stage. The period
of infusion is about 2 hours and the temperature is maintained at 65.5°C.
During this period, malt amylases degrade starch in aqueous solution to
produce sugars approximately in the following ratios: 7-10 per cent
monosaccharides, 48-55 per cent disaccharides, 12-15 per cent trisaccharides
and 20-30 per cent dextrin. By regulating the mashing conditions, the
proportion of various carbohydrates can be varied to suit the requirement of
the beer to be brewed. When steeping is complete, the extract, known as 'wort'
is filtered off through barley husks which settle on the perforated false
bottom of the mash tun.
The wort is then boiled with hops. This boiling destroys the malt enzymes and
sterilizes the wort. The essential oil and bitter substances of hops are
extracted and the proteins are coagulated. The coagulation of protein assists
in clarifying the beer. The liquor is filtered through spent hops which retain
the precipitated materials. The liquor, when cold, is seeded with yeast and
allowed to ferment for a few days during which time sugars are converted into
alcohol. When the fermentation is complete, the beer is allowed to stand for 1
or 2 days when yeast settles down.
After
fermentation, the beer is run off to storage tanks for maturing when secondary
fermentation takes place and the flavour and bouquet of beer develop. The
maturing process varies from only a few days for mild beer to several months
for strong beer: Next, the beer is pasteurized or sterile
filtered and bottled or canned, with the introduction of carbon dioxide under
pressure.
Variation
in the quality of beer, such as the strength of alcohol, colour and
extractives, depends upon the quality of malt, malt adjuncts used, mashing
method, amount of hops added and the condition of fermentation. Beer, ale,
porter and stout are beverages produced by top fermentation, while lager beer
is a product of bottom fermentation. Ale is made like lager
but is usually stronger in hop character and contains a higher alcohol
content. Porter is a heavier and darker drink made with longer dried, roasted,
or caramelized malt with less hops. Stout is like porter except that it has
heavier malt flavour much darker than any other malt drink. It has a stronger
hop taste than porter. The alcohol content of various beers varies from 2.5 to
7 g per cent. Beers produced in India contain 4--5 per cent alcohol and have a
calorific value of about 30 Kcal per 100 ml.
Saki
is Japanese beer, which is made entirely from rice. Whole grain rice is soaked
until it is quite soft and then steamed. The steamed rice is partially dried
by spreading on straw mats. It is then inoculated with a yeast-like mold and
after 10-14 days, the completely fermented material is filtered. This fluid is
placed in barrels to settle. After a few days, the clear liquid is withdrawn
and pasteurized giving Saki. It contains about 17 per cent or more alcohol by
volume.
Distilled
Spirits: Distilled
spirits are made by distilling fermented liquors. Whisky is made by the
fermentation and distillation of fermented cereal grains, brandy from wine and
rum from fermented molasses. Gin is a distilled spirit flavoured with juniper
(Juniperus communis) berries or some other aromatics. Distilled liquors
usually have 40 per cent alcohol and thus have excellent keeping qualities.
Usually, distilled liquors, other than gin, are allowed to mature before
consumption, e.g., whisky is matured in wooden caks for 5-15 years to become
smooth and mellow.
An
essential stage in making spirits is distillation. The liquid obtained by
fermentation from different materials contains dilute alcohol and is concentrated
by distillation. Originally, distillation was carried out in a pot still. To
obtain a concentrated alcoholic liquor, the distillation in a pot still has to
be repeated a number of times. To overcome this disadvantage, continuous
distillation stills have been developed. In spite of this development, pot
still distillation is still used for making the finest whiskys, brandies and
other renowned spirits. Pot still allows many of the volatile components which
contribute characteristic and subtle flavours to the drink to pass over with
the alcohol during distillation. The best of brandies, cognac, is made by
distilling twice in a pot still.
For
the preparation of gin and vodka, and for fortification of any other beverage
with alcohol, a colourless and tasteless spirit is required and this can be
obtained by distillation in a continuous still. Dilute alcohol from any source
when distilled in a continuous still can give 95 per cent alcohol. Such alcohol
is very pure and has only the odour and flavour characteristic of alcohol.
Such alcohol is known as neutral spirit (silent spirit).
Whisky is made using different cereals. Scotch malt whisky, the original
whisky, is made from malted barley and scotch grain whisky from barley malt
and other unmalted cereal grains. US whiskys are generally made from rye
(straight rye whisky) and maize (straight maize whisky). Canadian whisky is
made from maize, wheat, rye or barley. Irish whisky is made from malted barley
alone or with a mixture of unmalted barley, wheat, rye and oats.
In
the manufacturing process, the grain is converted into beer except for the
omission of hops and is distilled to obtain a distillate containing 80 per
cent alcohol by volume. It is then diluted with water and stored in charred
barrels. After the desired period of aging, the whisky is adjusted to the
required alcohol strength and bottled. The characteristic flavour of scotch
whisky is said to be due to the fumes from the peat used for firing malt kilns
and the characteristics of the water used.
Brandy
can be made from any fruit. Generally, `brandy' refers only to the distillate
from grape wine. Grape wine obtained from selected grapes is completely
fermented using pure cultures of yeast and distilled. The brandy obtained is
stored in oak casks and is allowed to age in a damp storage building for as
long as 20 years.
Rum
is an alcoholic beverage distilled directly from fermented sugarcane products,
such as sugarcane juice, syrup or molasses. The rum obtained by distillation
is stored in either charred, plain or reused barrels or vats. Rum readily
improves in character and flavour with aging. After aging, the strength of
alcohol is adjusted to 40 per cent and bottled.
Gin
is produced by diluting neutral spirit with
distilled water so that the alcohol content is 60 per cent. This is distilled
in a pot still in the head of which are placed juniper berries and other
aromatics. During distillation, the alcohol water vapour extracts the
flavouring principles. The distillate is then reduced to the required alcohol
strength by the addition of water and bottled. No aging is required for gin;
in fact, it may be harmful as the essential oils in gin may decompose with
time.
Vodka
is a distilled liquor without any identifying characteristics except that of
dilute alcohol. It is free from all traces of colour and flavour. Vodka is
made by diluting neutral spirit obtained from wheat or other cereal grains or
potato.
Liqueurs
are products obtained by steeping herbs, fruits, flowers or plants in neutral
or distilled spirits and distilling the resulting produce. To the distillate,
sugar is added to the extent of 2.5 per cent. As a rule, liqueurs are sweet,
and caramel colour or other colouring may be added. Liqueurs like Benedictine,
Drambuie, Creme-de-menthe are obtained this way. The recipes of most liqueurs
are closely guarded secrets.
