Alcoholic Beverages: Undistilled and Distilled

In this article we will discuss about undistilled and distilled alcoholic beverages.

A. Undistilled Beverages:

(i) Beer Fermentation:

Beer is an undistilled product of grain-mash fermentation brought about by yeast. Beer fermentation involves the conversion of starchy raw materials into sugars and then into alcohol. It is generally prepared from malted barley but other starchy grains, e.g..maize, rice are also used as raw materials. Yeasts especially Saccharomyces cerevisiae or S. carisbergensis are used in the fermentation process.

1. Commercial Production:

Five major steps are involved in the manufacture of beer (Fig. 40.2).

They are:

(i) Malting,

(ii) Mashing,

(iii) Fermenting,

(iv) Maturing, and

(v) Finishing.

(i) Malting:

The starchy grains are first malted. The malt is prepared by first soaking the grains in water and then allowing it to germinate at 17°C. During germination, large amount of amalyses, an enzyme, are produced which are subsequently involved in hydrolysing the starch into fermentable sugars. After the germination is completed, the grains are dried at 65°C.

(ii) Mashing:

After malting, the pure barley malt is invariably mixed with other grains such as corn, rye, sorghum, wheat, etc. It is called ‘ground malt’. The latter is first mixed with warm water at about 70°C and 5.0 pH. Mashing brings about partial hydrolysis resulting in the digestion of starch and protein; the partially hydrolysed solution of mash is filtered and this filtrate is called ‘beer wort’.

Beer wort serves as a rich nutrient medium for the microorganisms. Beer wort is now boiled with hops which are the papery scales of the female flowers of the hop vine, Humulus lupulus. The hops are added for flavour, aroma and mild antibacterial activity to prevent the growth of spoilage bacteria.

(ii) Fermenting:

The beer wort is now inoculated with a pure culture of Saccharomyces cerevisiae or S. carisbergensis and allowed to ferment at low temperature (5°C-14°C) for longer period (5-10 days).

(iv) Maturing:

The fermented beet wort is refrigerated at 0°C for several months (usually 6-8) to remove the harsh flavour and other undesirable characteristics.

(v) Finishing:

This is the final step in which the matured beer is carbonated, filtered and finally bottled, canned or barrelled. Bottled or canned beer is usually pasteurized at 60°C for about 20 minutes to prevent microbial spoilage.

2. Types of Beer:

(i) Lager beer:

It means literally, the stored beer. Lager beer is produced by ‘bottom’ fermentation and is rather high in alcohol (3.93%) and extract with a relatively low proportion of hops.

(ii) Bock beer:

It is a heavy beer, dark in colour and high in alcohol (4.69%). It is brewed for consumption in early spring.

(iii) Ale beer:

Ale beer is pale in colour, tart in taste, high in alcohol (4.75%) and contains more hops. This beer is produced by ‘top’ fermentation.

(iv) Porter beer:

It is a dark ale but sweeter than the usual ale in taste. It is brewed from dark or black malt to produce a wort of high extract. The flavour of hops is less distinct than that of normal ale.

(v) Weiss beer:

This beer is produced mainly from wheat as a result of ‘top’ fermentation. It is rather light (2.75% alcohol), possesses a distinct flavour of malt and hop, is tart and contains a large quantity of natural fermentation gas. Weiss beer is somewhat turbid in appearance.

(vi) Stout beer:

This beer is stronger porter beer possessing high alcohol concentration. It is dark in colour and possesses a sweet taste and strong flavour of malt. The flavour of hops is more pronounced than that of the porter beer.

(vii) Cereal beverage:

This beer contains less than 0.5% alcohol. It is sometimes referred to as “near beer”.

(ii) Wine Fermentation:

Wine is an undistilled product of fruit juice fermentation brought about by yeast. Wine is produced by the normal alcoholic fermentation of fruit juices, especially the grape juice. The microorganisms used in the wine fermentation are the various strains of Saccharomyces cerevisiae such as S. cerevisiae var. ellipsoidens.

1. Commercial Production:

Five major steps are involved in commercial production of wines.

They are:

(i) Crushing,

(ii) Fermenting,

(iii) Tanking,

(iv) Maturing, and

(v) Finishing.

(i) Crushing:

Grapes are harvested and ripened to a stage they contain highest sugar percentage. These fruits are crushed in a wine press and the crushed fruits with juice are called “must”. The must is generally treated with SO₂ to prevent microbial spoilage.

(ii) Fermenting:

The “must” is now inoculated with the starter culture of selected strain of the yeast and is aerated slightly to promote vigorous yeast growth. Once the fermentation starts, the rapid production of CO₂ maintains anaerobic condition. The temperature is kept usually at 25-30°C during fermentation period ranging from 5-11 days in order to inhibit multiplication of wild yeast and undesirable bacteria that live high temperature.

(iii) Tanking:

When most of the sugar is fermented the juice is separated from solid parts of fruits by allowing it to pass into tanks. These tanks, provided with valves to let the CO₂ escape, are completely filled with juice. The anaerobic condition for alcoholic fermentation is allowed to continue for about 12 days to increase the percentage of alcoholic concentration.

(iv) Maturing:

The wine is then allowed to mature in wooden tanks for 2 to 5 or more years. During maturing period the wine clears and develops the desired flavour due to formation of volatile ester.

(v) Finishing:

The wine may be finally cleared with the addition of gelatin, casein or Spanish clay. The cleared wine is filtered, bottled and pasteurized to prevent microbial spoilage.

2. Types of Wine:

Variety of grape, strain of yeast, nature of fermentation, etc. result in various varieties of wines. The latter differ from each other in so many attributes that it becomes difficult to classify them properly.

However, some important varieties of wine are as follows:

(i) Red wines:

The wines red in colour are put under this category. In preparing them the grapes are crushed and stemmed but their skins and seeds are left in the ‘must’. The alcoholic content percentage of these wines ranges from 11 to 12.

Examples:

Rose wines, Burgundy wines, Claret wines, Vinorosso wines, etc.

(ii) Dry wines:

Those wines which fall under this category contain too little sugar to be detected by taste, i.e., the sugars are almost completely fermented. Alcohol percentage of dry wines ranges from 19-20.

Examples:

Post wines, Takay wines, Muscatel wines, etc.

(iii) Sweet wines:

Those wines are “sweet wines” that have good quantities of unfermented sugars.

(iv) Sparkling wines:

These are the wines that are made effervescent by secondary fermentation in closed containers and contain CO₂. They too possess 11-12% alcohol.

Examples:

Sparkling Burgundy, Champagne, etc.

(v) Still wines:

The wines that do not contain CO₂ are called “still wines”. They contain 12-15% alcohol.

Examples:

Sherries, Vermouth, etc.

(vi) Fortified wines:

These are the wines which contain added alcohol in the form of ‘brandy’.

(iii) Other Undistilled Alcoholic Beverages:

Fermented undistilled alcoholic beverages are consumed all over the world. In some countries the use of particular undistilled beverages has been passed down from ancient times.

Some important ones are as follows:

(i) Kuass:

It is Russian and is prepared by mixing equal parts of barley malt, rye malt and rye flours adding boiling water and then inoculating with yeast for fermentation. Peppermint is added to the fermented product for flavour.

(ii) Sake:

It is Japanese and is prepared by fermenting rice. It is yellow in colour and contains 14-24% of alcohol. Hops are used in its preparation.

(iii) Pulque:

It is produced in Mexico and is prepared by allowing the sweet juice of agave to undergo fermentation. Fermentation is usually completed in one day.

(iv) Taette:

It is Scandinavian and is prepared from milk. It has a pleasant acid taste. Yeasts cause characteristic changes in flavour.

(v) Chicha:

It is a common fermented beverage of Peru and Bolivia and is prepared from maize by yeast- fermentation.

(vi) Hard cidar:

Hard cidar is produced by the fresh apple juice fermentation or, sometimes, pear juice fermentation for 24 hours.

(vii) Pombe:

It is an alcoholic beverage prepared by allowing millet grain to sprout and undergo conversion of starch to sugars and by permitting a spontaneous fermentation of the starch water.

(viii) Ginger beer:

The beverage is characterized by its distinct acid nature, the ginger flavour, and the presence of a small amount of alcohol.

(ix) Palm vine:

Palm wine or ‘Toddy’ (tori) is prepared from the fermented juice obtained from the inflorescence of many palms. The important species of palms which yield toddy and Phoenix dactylofera, Borassus flavellifer, Cocos nucifera, etc. When toddy is distilled, it yields ‘arrack’.

(x) Root beer:

It contains an infusion of various roots, barks and herbs with the addition of sugar and yeast. The herbs generally used are ginger, sarsaparilla and wintergreen. Fermentation sets and the beverage becomes charged with CO₂.

(xi) Mead:

This undistilled fermented alcoholic beverage is of great antiquity. It is obtained from honey and water and possesses a wine like flavour.

B. Distilled Beverages:

(i) Whisky:

Whisky is distilled from fermented grain-mash containing upto 50% ethyl alcohol.

Following are some varieties of whisky:

(i) Malt whisky:

This whisky is manufactured by microbial fermentation and subsequent distillation of malted barley (barley grains are soaked in water and then germinated at 17°C).

(ii) Grain whisky:

This whisky is manufactured by the microbial fermentation and subsequent distillation of a mixture of malted and un-malted barley with un-malted maize.

(iii) Scotch whisky:

Malt whisky is matured (aged) in oak casks at least 3 years and then is blended with grain whisky. This new product is scotch whisky.

(iv) Bourbon whisky:

This whisky is manufactured by the microbial fermentation of a grain-mash in which corn is predominant (at least 51 %).

(v) Irish whisky:

This whisky is prepared from a grain-mash in which rye is predominant.

(vi) Arrak (Far East) and Sake (Japan) whisky:

This whisky is prepared from microbial fermentation of rice-grains. Since the rice is starchy, its starch is hydrolysed by enzyme amylases derived from Aspergillus oryzae before fermentation.

(ii) Rum:

Rum is any alcoholic distillate from the fermented juice of sugarcane, sugarcane syrup, sugarcane molasses or other sugarcane by-product and contains about 40% alcohol. Blackstrap molasses containing 12-14% fermentable sugar are fermented by Saccharomyces cerevisiae or other yeasts at pH 4.0-4.7 and initial temperature of 27°C which rises finally to 35.5°C. Fermentation is completed within 3 to 7 days.

Rum is usually aged (matured) in charred white-oak barrels and possesses a characteristic flavour, aroma and colour. Rum may be used in the preparation of ice cream, candies, in curing of tobacco and, sometimes, as medicine.

(iii) Gin:

Gin is the liquor which is prepared by distillation from a fermented mash of malt or raw grain. The finest gin is distilled from the malt of barley and rye. It requires several distillations. The flavour of gin and its medicinal value are due to oil of juniper.

(iv) Brandy:

Brandy is the distillation product of fermented grape juice (wine) and contains about 40-50% alcohol. The best brandy is made in France in the Charente district. The finest grade of brandy are made from the white wines. The brown colour of brandy develops when it is stored in wooden casks. Sometimes, the brandy is coloured with caramel. It contains about 60-70% alcohol.

(v) Vodka:

It is Russian alcoholic beverage (distilled) produced by the yeast fermentation of potatoes. It is allowed to age for long periods in wooden casks; flavour and aroma are introduced into the purified alcohol during the blending process.

(vi) Cashew Apple Liquor (Fenny) of Goa:

Cashew apple (Anacardium occidental) liquor is an unique liquor obtained from the excessive distillation of yeast — fermented cashew apple juice. This liquor is commonly known as ‘Fenny’ and is a liquor perfect by itself without the addition of any extraneous ingredients and possessing its own characteristic flavour.

Goa (in India) is the only place where fenny is prepared for the past four centuries. Cashew apple liquor contains sugar in the form of glucose. The latter is fermented by yeast and the fermented liquor is subjected to excessive distillation in most modern distillery. The distilled product is bottled only after it has been aged (matured) in wooden barrels for a sufficiently long period.