The document discusses different types of alcohols including ethanol. It describes how fermentation of sugars by yeast produces alcoholic beverages like wine, beer and mead. Distillation increases the alcohol concentration producing spirits like whiskey, gin and rum. Fermented beverages have 4-14% alcohol while distilled beverages have 37.5-75% alcohol. The document provides details on the processes of fermentation and distillation, and classifies various alcoholic beverages.

1. ALCOHOL
INTRODUCTION________________________________
Alcohol is a mobile, volatile fluid obtained by fermentation of a sugar containing
liquid. Its strength (concentration) can be further increased by distillation.
Alcohol, in general, is a family of organic chemical compounds. Thus, there are various
kinds of alcohols in this alcohol family. It includes Methanol (Methyl alcohol), Ethanol
(Ethyl Alcohol), Propanol (Propyl alcohol), Butanol (Butyl Alcohol) and so on. All these
alcohols are obtained on replacing one Hydrogen (-H) atom by one Hydro-oxide (-OH)
atom in its parent chemical compound. For example: one Hydrogen atom in Methane
(CH4) is replaced by one Hydroxide atom to form Methanol (CH 3OH), one Hydrogen
atom in Ethane (C2H6) is replaced by one Hydroxide atom to form Ethanol (C 2H5OH) and
so on.
Methyl alcohol (methanol) and Ethyl alcohol (ethanol) are the main alcohols in this
family. Out of these two organic chemical compounds, Ethanol (C 2H5OH) is potable and
if sensibly consumed, is a beneficial alcohol. It has a faint but pleasant ethereal smell
and it is the alcohol that shall be dealt with. On the other hand, Methanol is a powerfully
dangerous poison if drunk. Its importance is that it is widely used in industrial
processes.
NOMENCLATURE_______________________________
The name Alcohol is derived from the Arabic word al-kohl. Kohl is a black, very fine
staining powder that is used cosmetically for staining the eyelids (and is particularly
used by ladies). Later, the name was applied to highly refined chemical powders and
essences and then to spirits produced by distillation and rectification and now to any
alcohol (alcoholic beverage) in general.
ALCOHOLIC BEVERAGE_________________________
An alcoholic beverage is any potable (meaning drinkable) liquid containing ethanol or
ethyl alcohol. In USA, Federal Government during the Prohibition time defined that it
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2. may have as little as 0.5% to 95% alcohol by volume. However, social and economic
factors, so also the taxation laws determine what are alcoholic beverages. For example:
Certain bitters and medicinal compounds contain as much as 40% alcohol; even then
they are not considered as alcoholic beverages and are not taxed.
HOW IS POTABLE ALCOHOL (ALCOHOLIC
BEVERAGE) OBTAINED?_________________________
All alcohols or alcoholic beverages are obtained by a process called fermentation. It is
concentrated or increased in strength by a process called Distillation. Both these
processes are discussed below:
FERMENTATION
French biologist Louis Pasteur (1822-95) explained scientifically the principle of
fermentation, which is basic to the making of all alcoholic beverages. When yeast is
added to any sugar containing liquid, it reacts with sugar of the liquid to form
alcohol and carbon dioxide. This fundamental process is called fermentation. If
this liquid is not protected from air, it is later converted to vinegar.
Thus, fermentation is the breaking down of organic substances (sugars particularly
maltose) by enzymes secreted by yeast cells into mainly ethyl alcohol and carbon
dioxide gas. This is an exothermic reaction i.e. heat is liberated during this reaction.
Fermentable Sugars + Yeast Enzymes → Alcohol + Carbon Dioxide Gas↑ + Heat
Scientifically describing, the enzymes secreted by yeast cells react with one molecule of
sugar (maltose) to produce two molecules of Ethanol and two molecules of Carbon
Dioxide Gas. Heat is generated during this reaction.
C6H12O6 + Yeast Enzmyes → 2CH3CH2OH + 2CO2↑+ Heat Energy
Carbon dioxide gas is usually but not always allowed to escape. Here, the alcohol
(ethanol)-a liquid remains behind in the original liquid, which is then called a
fermented alcoholic beverage. These fermented alcoholic beverages are preferably
rested, aged, matured and blended before being bottled for sale. Fermented alcoholic
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3. beverages have an alcoholic strength of generally 4% to 14% by volume. For example:
Wines, Mead, Pulque, Cider, Perry, Beers etc.
A point, which is very important, is that alcohol is obtained from ingredients containing
sugar. For example: grape juice, apple juice, pear juice etc. But, it can also be obtained
from ingredients such as grain, cereals and potatoes, which have no sugar but have the
potential to form sugar i.e. these cereals have a lot of starch present in them. Once the
starch is converted into fermentable sugars, mainly maltose, yeast is introduced and
fermentation begins.
Another point that requires mention is that certain fermented alcoholic beverages like
Beer, Sake etc are brewed before they are fermented. i.e. the mixture of grist (mashed
cereals) and hot water is brewed to extract flavour, taste and aroma before being
fermented.
NAMES AND BASE INGREDIENTS OF SOME FERMENTED
ALCOHOLIC BEVERAGES
Table, sparkling, fortified and other wines - Grapes
Cider - Apples
Perry - Pears
Mead - Honey
Pulque - Blue Agave or Maguey
NAMES AND BASE INGREDIENTS OF SOME BREWED AND
FERMENTED ALCOHOLIC BEVERAGES
Lagers, Ales and other beers - Grains
Sake - Rice
DISTILLATION
The process of separating one or more liquids by heating a mixture of liquids is
called distillation. It involves the sub-processes of evaporation and condensation.
The principle of distillation is that ethyl alcohol vaporizes at a lower temperature (78.5
°
C) than water, which vaporizes at 100 °C. So, when any fermented liquid is heated in an
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4. enclosed vessel called a still to a temperature of 78.5 °C, water remains in the still and
alcohol vaporizes which is channeled off and later condensed to obtain a concentrated
alcoholic liquid again. This concentrated alcoholic liquid obtained after distillation is
called a spirit-a kind of distilled alcoholic beverage. This distilled alcoholic beverage
(spirit) depending upon the method of distillation (whether pot still or patent still) may
be rested, matured, blended, and reduced in strength by adding de-ionized water and
probably given colour enhancement before being bottled for sale. For example: Gin,
Vodka, Whisky etc. These fermented and distilled alcoholic beverages generally have
an alcoholic strength ranging from 37.5% to 57.5% by volume. But, some distilled
alcoholic beverages have an alcoholic strength as high as 75% by volume.
Important points that are notable in this process are as follows:
(i) The still is the apparataus, which allows the seperation of water and alcohol from a
fermented liquid to be carried out (thus, a fermented liquid is a must for distillation).
Also, the quality of the final product depends a lot on the shape and size of this still.
(ii) Water is constantly vaporizing to some extent so every distillation will contain water.
(iii) The final product obtained after distillation also consists of Congeners. Congeners
are minor amounts of aldehydes, ethers, esters, volatile acids, organic compounds and
also fusel oils (higher alcohols like propanol, butanol etc) which give the product its
distinctive, individual character of taste, flavour and aroma. They come along with the
vaporizing process or by the extraction from the residue. These are further enhanced as
the spirit ages in wood. For example: Aldehydes are produced from a combination of
alcohols and air, and are particularly important for the character of a spirit. Esters result
from a combination of acids and alcohol and form a volatile substance that contributes
to the aroma of a spirit.
There are two main methods of distillation by which distilled alcoholic beverages (spirits)
may be obtained:
(i) POT STILL: It originated in the middle ages and is associated with separate, slow and
low-temperature distillations. As a result, the end product contains a good proportion of
congeners and spirits obtained by this method have to be matured for atleast two years by
law. But, usually it is matured longer than that. The entire heavy, highly flavoursome spirits
are distilled by this method. For example: brandy, malt whisky, dark rums, tequila and fine
Calvados etc.
The pot still is shaped like a giant onion and consists of two parts: a still and a worm
condenser. The still is made of copper because it is a good conductor of heat and also
resists the effects of acids, which are normally capable of dissolving metal. The copper worm
condenser is connected to the still by a copper pipe. The worm passes through a jacket of
flowing cold water, which speeds up the condensation of the alcohol-rich vapours. The pot
still is time consuming and costly to operate. It needs to be cooled, cleaned and refilled after
each distillation, but it produces spirits of remarkable individuality, quality and flavour.
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5. POT STILL
Working: The fermented liquid is placed in the still and slowly heated over a naked flame.
When the temperature reaches 78.5°C the alcoholic vapours rise and pass through the worm
to a condenser. Here the vapours are condensed back into a liquid containing about 30%
alcohol. This is re-distilled. The first part of the distillate to emerge is known as the heads
(foreshots) and contains a high proportion of methanol. This is put to one side. The central
portion (heart) of the distillation - the best part -- has an alcoholic strength of about 80% and
is channeled into the spirit receiver and ultimately into maturing casks. The final part of
the distillation, known as tails (feints or after-shots), is weak in alcohol and contains the
nauseating fusel oils and other impurities. The heads and tails are sent back to be re-
distilled and refined. The new spirit (distilled alcoholic beverage) may be reduced in
strength by the addition of deionised water, which does not react with the chemical
elements of the spirit. It is then well matured before bottling and sending it for sale.
(ii) PATENT STILL: The patent still or Coffey still is named after its inventor Aeneas
Coffey-a Dublin excise officer. It works on the principle of distillation by steam and
produces a continuous flow of high strength alcohol. It uses rectification to make the
end product as pure and congener-free as possible. As a result, no maturing period is
required by law and the resultant product may be sold immediately it has been
produced. It is cheaper than the pot still to operate as it is lighter on fuel and does not
require the labour-intensive tasks of emptying, cleaning and refilling. The patent still is
associated with all the light spirits such as vodka, gin, white and light rums, grain
whiskies etc.
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6. PATENT STILL
Working: The patent still consists of two columns about 18 m high. The analyzer
separate the constituent liquid parts while the rectifier condenses the alcoholic vapours,
raises the strength of and purifies the spirit. Each column is sub-divided horizontally into
chambers by perforated copper plates, which have a drip pipe leading to the chamber
underneath. Both columns are preheated by steam and the fermented liquid (also called
wash) enters at the top of the rectifier through a pipe and gradually descends.
By the time, the wash reaches the bottom of the rectifier through the pipe; it is almost at
boiling point. It is then pumped into the analyser where it gradually makes its way
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7. downwards through perforated plates and bubble caps. As it descends, it is met by a
current of raw steam, which has been injected under pressure into the bottom of the
analyser. On contact, the steam boils the wash and produces alcoholic vapours that rise
and are channelled by a pipe into the bottom of the rectifier. The spent wash is removed
from the bottom of the analyser.
Meanwhile inside the rectifier, the alcoholic vapours pass through a series of perforated
plates. As they rise they meet the cold wash being carried down the rectifier by the
wash coil. Partial condensation takes place - the vapours getting cooler and the wash,
on its way to the analyser, getting hotter. When the spirit vapours reach two-thirds of
the way up in the rectifier, they hit a cold spiral plate or water frame and precipitate.
The first liquid to emerge - the heads or foreshots - is removed and sent back to the
analyser because it is pungent and needs further refining. The comparative pure spirit
that follows is guided into a spirit receiver. The new spirit is then reduced in alcoholic
strength by deionised water and matured for a short time before being treated
according to style.
NAMES AND BASE INGREDIENTS OF SOME DISTILLED ALCOHOLIC
BEVERAGES (SPIRITS)
Cognac, Armagnac & other brandies - Grapes or Wine
Whisky - Grains or Beer
Vodka, Kornbranntwein - Grains/Potatoes
Light, golden & dark Rums - Molasses (Sugarcane)
Arrack - Dates, Palm Sap
Mezcal, Tequila - Blue Agave or Pulque
Gin - Grains
Aquavit - Grains, Potatoes
NAMES AND BASE INGREDIENTS OF SOME DISTILLED ALCOHOLIC
BEVERAGES FROM FRUITS OTHER THAN GRAPES
(EAU DE VIE DES FRUITS)
Calvados - Apples
Slivovitz, Mirabelle, Quetsch - Plums
Kirsch - Cherries
Eau de Vie de Poire - Pears
Eau de Vie de Fraise - Strawberries
Eau de Vie de Framboise - Raspberries
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8. CLASSIFICATION AND TYPES (STYLES) OF
ALCOHOLIC
BEVERAGES_______________________
The main purpose of classification of Alcoholic Beverages are two: (i) to provide the
base for accessing and collecting taxes by the government and (ii) to protect the
consumer by making them understand the differences between the products.
The chart showing the classification and different styles of alcoholic beverages is given
hereby:
It shows that ALCOHOLIC BEVERAGES are basically classified into FERMENTED
ALCOHOLIC BEVERAGES and DISTILLED ALCOHOLIC BEVERAGES depending
upon whether they are fermented or distilled.
These FERMENTED ALCOHOLIC BEVERAGES are classified into WINES, MEAD,
PULQUE, CIDER, PERRY, BEER, SAKE etc on the basis of base ingredients used.
WINES are further categoried into TABLE, SPARKLING, FORTIFIED, AROMATISED,
TONIC, VIN DOUX NATURELA, ORGANIC etc. on the basis of their
nature/characteristics. All these WINE TYPES can also be classified (i) on the basis of
their colour into RED, PINK (ROSE) AND WHITE, (ii) on the basis of their body into
HEAVY BODIED, MEDIUM BODIED OR LIGHT BODIED (especially red wines) (iii) on
the basis of their degree of sweetness into DRY, MEDIUM DRY, MEDIUM SWEET,
SWEET etc (especially white wines). (iv) on the basis of alcohol content into LOW
ALCOHOL WINES (max 1.2% by volume), DE-ALCOHOLISED WINES (max 0.5% by
volume) and ALCOHOL FREE OR NO ALCOHOL WINES (max 0.05% by volume).
BEER is classified on the basis of type of fermentation (bottom or top) into mainly
LAGERS and ALES. However, there are other types like PORTER, PILSNER, STOUT,
GUINNESS, BOCK, STEAM etc.
The DISTILLED ALCOHOLIC BEVERAGES are classified into SPIRITS, LIQUEURS,
BITTERS etc on the basis of their nature and characteristics. SPIRITS are further
categorised into WHISKY, GIN, RUM, VODKA, TEQUILA, BRANDY, CALVADOS, EAU
DE VIE DES FRUITS AND OTHERS depending upon the base ingredient used.
Further, famous WHISKIES are of four main types depending upon the country of origin,
base ingredient, method of manufacture etc: SCOTCH, IRISH, AMERICAN AND
CANADIAN. GIN styles include FRUIT GINS, PLYMOUTH GIN, LONDON DRY GIN,
HOLLANDS GIN, MALT WINE etc. RUM styles are LIGHT RUM, GOLDEN RUM AND
DARK RUM. TEQUILA styles include WHITE and GOLDEN (ANEJO). BRANDY types
include COGNAC, ARMAGNAC AND OTHERS. EAU DE VIE DES FRUITS include
EAU DE VIE DE POIRE, FRAISE, FRAMBOISE etc. LIQUEURS are further classified
into GENERIC LIQUEURS and BRANDED LIQUEURS.
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9. 9

10. 10

11. ALCOHOLIC STRENGTH_________________________
The concentration of alcohol in an alcoholic beverage is called its alcoholic strength.
Alcoholic strength of any alcoholic beverage is required to be measured so that the
governments can tax them properly and consumers might come to know about it,
forcing them to drink sensibly. Various methods are followed all over the world to
determine the alcoholic strength of an alcoholic beverage. Traditional or Primitive
methods were followed before the scientific methods were evolved. Both these kinds of
various methods are listed here:
PRIMITIVE METHODS: It includes two methods:
(a) Gunpowder: To test alcoholic strength initially distillers mixed equal quantities of
spirit and gunpowder and applied a flame to it. If the mixture failed to ignite, the spirit
was too weak; if it exploded or burned too brightly, it was too strong, but if it burned
evenly with a mild blue flame, it was 'proved' suitable and safe to drink (potable).
Hence, the word “proof”.
(b) Clarke’s Float: In the seventeenth century, Clarke invented a weighted float. When
this float was dropped into a spirit, the depth to which it sank revealed the density of the
liquor and the alcoholic strength could be calculated from this. It was then able to
calibrate a particular strength as proof and any with a greater or lesser concentration of
alcohol was 'overproof’ or 'underproof’ respectively.
MODERN SCIENTIFIC METHODS: It includes four methods:
(a) Sykes Hydrometer: In 1816, Sykes introduced Sykes Hydrometer. Sykes
determined that 100° was proof and that pure alcohol was 175° (75° overproof). On this
scale, the figure for pure alcohol is I 3/4 times the figure accorded to proof spirit. In other
words, 100° proof equals 57.1% alcohol and 42.9% water. The system also called
British system became traditional throughout the United Kingdom where spirits were
sold at a potable strength of 70° proof (30° underproof). So to convert the British proof
into percent by volume of alcohol, simply multiply the proof by four and divide by seven.
70 X 4 = 40%
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(b) Gay-Lussac System: Gay-Lussac (1778-1850) invented this system, which was
adopted throughout mainland Europe. In Gay-Lussac or GL system 0° is the absence of
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12. alcohol and 100° pure alcohol. Here, the alcoholic strength is measured at 15°C. Thus,
degree equals percentage.
© American System: The Americans introduced their own system that was reasonably
logical. They decided that proof spirit was an exact balance of alcohol and water and
that pure alcohol is 200° Proof. Each degree of proof equals one-half percent of alcohol.
So, a spirit marketed at 90° proof would contain 45% of alcohol by volume.
(d) OIML Scale: The Organisation Internationale de Metrologie Legale (OIML)
expresses alcoholic strength as a percentage by volume of alcohol (0% - 100%). It is
very similar to the Gay-Lussac system except that OIML measures strength at 20°C.
Thus, Gay-Lussac system gives a slightly higher reading. The difference is almost
negligible except when deciding excise duty on very large quantities of drink. This
system is followed now a days in the continent of Europe.
APPROXIMATE ALCOHOLIC STRENGTHS__________
TYPE ALCOHOL BY VOLUME
Alcohol free - maximum 0.05%
De-alcoholised - maximum 0.5%
Low alcohol - maximum 1.2%
Cider - 4 – 6% but ‘specials’ upto 8%
Beer - Light: 3 – 6%, Strong: 8 – 10%
Table Wines - 8 – 15%, usually 10 – 13%
Sparkling Wines - 10 – 13%
Fortified Wines - 16 – 22%
Aromatised Wines - 14 – 20%
Vin doux Naturel - 15 – 18%
Spirits - usually 37.5 – 45%, some upto 57.5%
Liqueurs - 17 – 55%
BENEFITS OF ALCOHOL_________________________
Some of the benefits of alcohol are as follows:
(i) Alcohol is not a direct cause of any disease nor will it cure any disease. But, it is
used medicinally for treatment of certain physical conditions. It is world’s second oldest
disinfectant.
(ii) Alcohol is good when drunk in moderation. It is a source of nutrition and energy as it
creates heat.
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13. (iii) As a food it is an appetizer, an accompaniment, an enhancer of flavours and taste,
aids digestion and sometimes used as correctifs as well.
(iv) It accentuates sensory perception, sharpens memory and gives some protection to
the heart and blood vessels by raising the level of good cholesterol.
(v) It depresses centres of anxiety, relieving tension and stress. Sometimes, it
exhilarates the spirit.
ABUSES OF ALCOHOL__________________________
Alcohol must be treated very seriously and with respect. It is only a problem to those
who abuse it. Long time heavy drinking may lead to:
(i) serious illness including liver cirrhosis, hastening of age and deterioration of nervous
system.
(ii) situations where it becomes an impediment in person’s speed and quality of
performance,
(iii) the person becoming a danger to themselves and others; especially when driving or
operating machines.
(iv) personality changes in extreme cases. They become extremely unpleasant and
unreliable.
(v) a person becoming unfit for work and a cause for embarrassment and burden to
their families and friends.
SAFE & SENSIBLE DRINKING_____________________
Ingested alcohol is readily and rapidly absorbed into the bloodstream. The liver burns
up almost all this alcohol. Whatever is remaining behind is discharged via urine or
perspiration. The liver burns up only one unit of alcohol per hour and as it being a living
organ cannot cope up with too much alcohol. To avoid any damage to health, the
alcoholic intake should be limited to 21 units a week for men and 14 units a week for
women. Care should be taken that this consumption should be spread throughout the
week. Usually,
1 unit = 0.5 pint (28 cl) of ordinary beer or lager
1 glass (12.5cl) of wine
1 measure (2.5cl) of spirit
1 glass (5cl) of sherry
1 measure (5cl) of vermoth or other aperitif
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14. The limit for drivers is generally 80 mg of alcohol in 100 ml of blood. The number of
units required to reach this level varies between individuals but it can be as little as 3
units. After consumption, alcohol remains in the bloodstream for up to 18 hours.
_____________________________________________________________________
THINK IT OVER_________________________________
1. Explain the following terms: (a) Pulque (b) Mead (c) Distillation (d) Alcohol [Nov-
05 / Nov-04]
2. Explain any four methods of calculating the strength of alcoholic beverages. [Nov-
05 / April-05 / April-04]
3. Differentiate between Pot Still Distillation and Patent Still Distillation. [Nov-05 /
April-05]
4. List the raw material required for the manufacturing of the following: (a) Gin (b)
Vodka (c) Canadian Whisky (d) Tequila (e) Perry (f) Arrak [Nov-05]
5. Drawing a chart, classify alcoholic beverages. [April-05 / Nov-04]
6. Explain in one sentence: (a) Cider (b) Pastis [April-05]
7. Draw and describe Pot Still Distillation. [April-05]
8. With the help of a diagram, explain the working of Patent Still Distillation. [Nov-04 /
April-04]
9. Define “Proof”. Also explain: (a) British Proof (b) U.S. Proof [Nov-04]
10. Drawing the classification chart of alcoholic beverages. Also classify the following
there-in: Underberg, Riesling, Caracao, Kirsch, London Dry Gin, Weissbier,
Drambuie, Malaga, Spumante, Trappiste, Calvados, Rye, Sekt, Perry, Gypsy, Kir,
Barolo, Anjou [April-04]
11. Write a short-note on “Fermentation”. [April-04]
12. 80° USA Proof is equivalent to _______________ ° GL Proof. [Nov-04]
13. 100° BP is equivalent to ________________ ° GL Proof. [Nov-04]
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15. The limit for drivers is generally 80 mg of alcohol in 100 ml of blood. The number of
units required to reach this level varies between individuals but it can be as little as 3
units. After consumption, alcohol remains in the bloodstream for up to 18 hours.
_____________________________________________________________________
THINK IT OVER_________________________________
1. Explain the following terms: (a) Pulque (b) Mead (c) Distillation (d) Alcohol [Nov-
05 / Nov-04]
2. Explain any four methods of calculating the strength of alcoholic beverages. [Nov-
05 / April-05 / April-04]
3. Differentiate between Pot Still Distillation and Patent Still Distillation. [Nov-05 /
April-05]
4. List the raw material required for the manufacturing of the following: (a) Gin (b)
Vodka (c) Canadian Whisky (d) Tequila (e) Perry (f) Arrak [Nov-05]
5. Drawing a chart, classify alcoholic beverages. [April-05 / Nov-04]
6. Explain in one sentence: (a) Cider (b) Pastis [April-05]
7. Draw and describe Pot Still Distillation. [April-05]
8. With the help of a diagram, explain the working of Patent Still Distillation. [Nov-04 /
April-04]
9. Define “Proof”. Also explain: (a) British Proof (b) U.S. Proof [Nov-04]
10. Drawing the classification chart of alcoholic beverages. Also classify the following
there-in: Underberg, Riesling, Caracao, Kirsch, London Dry Gin, Weissbier,
Drambuie, Malaga, Spumante, Trappiste, Calvados, Rye, Sekt, Perry, Gypsy, Kir,
Barolo, Anjou [April-04]
11. Write a short-note on “Fermentation”. [April-04]
12. 80° USA Proof is equivalent to _______________ ° GL Proof. [Nov-04]
13. 100° BP is equivalent to ________________ ° GL Proof. [Nov-04]
*****************
**************
**********
******
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