Thursday, October 11, 2012


Alcoholic Beverage

The word `beverage` has been derived from the Latin word “Bever” which means ‘rest after work’. As after work we tend to feel thirsty due to the fluid loss through perspiration and get inclined to drink water or other potable beverages to recover the loss.

Beverages are potable drinks which:

1.      Quench thirst

2.      Refresh body i.e. replenishment of fluid in the body loosed due to perspiration

3.      Stimulate body

4.      Nourish body by providing necessary nutrients

5.      Provides energy in the form of sugar or alcohol

Any beverage containing ½% of alcohol by volume to 76% alcohol by volume (ABV) is considered to be an alcoholic beverage. Those beverages with more than 76% alcohol are considered as Medicine such as Anesthetics.

History of Alcohol

Ancient Egyptians used fermented grapes to make prototype Beer. Wine came into existence after Beer but wine became an integral and crucial part of Egyptian, Greek and Roman`s culture and religion. Wine was also used for culinary purposes as a marinade and in sauces.

Fermentation

In 1857, Louis Pasteur, a French Biologist, was the 1st person to explain the principle of Fermentation.

         C6H12O6                                                                                         2C2H5OH                    +      2CO2                                          (One Molecule of Sugar)  (With the action of Yeast)   (2 Molecules of Ethyl alcohol) & (2 Molecules of                                                                                                                                               Carbon dioxide)

 

Fermentation is the breaking down of organic substances by enzymes which have been secreted by the yeast cells resulting in the chemical change, where one molecule of sugar is split into 2 molecules of Ethyl Alcohol and 2 molecules of Carbon Dioxide.

 

To undergo the process of fermentation, Yeast cells are required. The Yeast cells are single cell organisms, which are essential for the process of fermentation. There are two broad categories of yeast:

1.      Natural Yeasts                                    2. Cultured Yeasts

 

1.      Natural Yeast: These are a variety of naturally occurring yeast, which are found in the air, fruits, grains, etc. They are present in the atmosphere and in almost every fruit especially grapes. A single grape before fermentation carries on its skin 1, 00,000 wine yeast, 1, 00,000 molds and up to 10 million wild yeast. The common species of wild yeast are Hensenula, Klöchera, Pichia, etc.

 

2.      Cultured Yeast: These are selected strains of yeast which are cultivated in a Laboratory in a controlled environment. These are used as they efficiently convert sugar into alcohol. Saccharomyces is the main yeast family used.

                      There are four varieties of Saccharomyces which are important for production of Alcohol

1.      Saccharomyces Cerevisiae: This is a traditional Beer Yeast used to prepare Ale or top fermented type of Beer. This yeast reacts in warmer temperature and at the top of the brew. Due to this activity this yeast is also known as Top Fermented Yeast.

 

2.      Saccharomyces Carlsbergensis: This is beer yeast used to prepare Lager or bottom fermented beers. This yeast reacts in lower temperature and at the bottom of the Brew. Due to this activity this yeast is also known as Bottom Fermented Yeast.

 

3.      Saccharomyces Apiculatus: This yeast is known as wild yeast or starter yeast in the manufacturing of wine as these have weak strains which are active only up to 4% alcohol and is killed after that. The wild yeast is aerobic in nature i.e. reacts only in the presence of oxygen and has low tolerance, so So2 is added to kill acetobacter, which converts wine into vinegar.

 

4.      Saccharomyces Ellipsodium: This is a true wine yeast as it ferments from 13% - 16% alcohol depending upon sugar content. This yeast is both Aerobic and Anaerobic in nature and also has high tolerance to So2.

Fermentation Temperature

·         Wine yeast can work only between 5oC and 35oC.

·         White wine ferments slowly and at low temperature between 15oC to 20oC, to impart delicacy and fragrance. 

·         Red wine ferments quickly and at high temperature between 25oC to 30oC which helps in extracting more color and body for the wine.

Malolactic Fermentation / Secondary Fermentation

This is the 2nd fermentation which a wine undergoes which usually takes place in the spring time following the ‘Vintage’. In this fermentation harsh ‘Malic Acid’ is converted in soft ‘Lactic Acid’ and CO2. There is no increase in alcohol, only a decrease in the acidity of wine. This fermentation helps in making wine softer and more palatable.

Chapatalization

This is a process of addition of sugar or concentrated Must (unfermented grape juice), to the unfermented grape juice in order to increase the alcoholic content of wine.

The grapes do not ripen properly (amount of sugar content present in grape) in countries which have colder climate. Therefore, the Must produced from these grapes have low sugar content, resulting in low alcoholic wine. In order to avoid this situation, some amount of sugar or concentrated must is added to the new unfermented juice. The process is known as Chapatalization.

Acidification: It is the process of conversion of wine into Vinegar.

Must: It is an Unfermented Grape Juice.

Mark: Crushed grape skin, stalk and seed is known as mark.

 

Distillation

It is defined as the process of simultaneous evaporation and condensation of a liquid to purify them. It involves extraction of alcohol from fermented liquid by the action of heat which vaporizes them. Alcohol has a low boiling point (78oC) as compared to water which has a boiling point of 100oC, due to this alcohol vaporizes before water and when these vapors hits a cool surface it forms a dripping condensation and changes into liquid form with much higher percentage of alcohol then the fermented Brew.

For the production of distilled alcoholic beverage (Spirits) two different types of Apparatus / Stills are used:

1.      Pot Still

2.      Patent Still

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