Microbes, specifically yeast (Saccharomyces cerevisiae), have been used for centuries for the production of beverages like wine, beer, whisky, brandy, and rum. For this purpose, the same yeast commonly called Brewer’s yeast is used for fermenting malted cereals and fruit juices to produce ethanol.
The processing of these fermented broths determines the type of alcoholic drink produced. Depending on whether the product is distilled or not, beverages are categorized into two groups:
In the given options, Beer is the only beverage that is produced without distillation. Therefore, option (A) is the correct answer.
Microbes play a vital role in human welfare, and one of their most significant industrial applications is in the production of alcoholic beverages. This process relies on the metabolic activity of yeast during fermentation.
Industrial scale production requires growing microbes in very large vessels called fermentors. One of the primary uses of these fermentors is the production of ethanol through the fermentation of sugars found in malted cereals or fruit juices.
Yeast is a unicellular fungus. The specific strain Saccharomyces cerevisiae is known as Brewer's yeast when used in the beverage industry and Baker's yeast when used in the baking industry. It performs anaerobic respiration (fermentation) to convert sugars into ethanol and carbon dioxide.
The chemical reaction can be represented as:
$$C_6H_{12}O_6 \xrightarrow{Yeast} 2C_2H_5OH + 2CO_2$$
Alcoholic drinks are distinguished by the raw material used for fermentation and the type of processing (with or without distillation).
| Beverage | Raw Material | Process |
|---|---|---|
| Wine | Grapes / Fruit Juice | Non-distilled |
| Beer | Malted Barley | Non-distilled |
| Whisky | Malted Cereals | Distilled |
| Brandy | Fruit Juices (Wine) | Distilled |
| Rum | Molasses (Sugarcane) | Distilled |
Distillation is a process of separating components from a liquid mixture by selective evaporation and condensation. In the context of alcohol, it is used to purify the ethanol and remove excess water, thereby significantly increasing the alcohol percentage (Alcohol by Volume or ABV). Non-distilled beverages like beer typically have 3-8% alcohol, while distilled ones like Rum or Whisky can have 40% or more.
This topic falls under "Microbes in Human Welfare" in the Class 12 Biology NCERT syllabus. Questions regarding the distilled vs. non-distilled nature of beverages are high-yield for both NEET and Board exams. You should also be familiar with other microbial products like antibiotics (Penicillin), organic acids (Citric acid, Acetic acid), and enzymes (Lipases, Proteases).
"W.B." for Non-Distilled: Think of "White Board" → Wine and Beer are the non-distilled ones. Everything else commonly mentioned (Whisky, Brandy, Rum) is distilled.
1. Why are some alcoholic beverages distilled while others are not?
Distillation is used to increase the alcohol concentration. Non-distilled beverages like beer and wine have lower alcohol content (usually <15%) because yeast dies at higher concentrations.
2. Which microbe is used for the production of beer?
The yeast Saccharomyces cerevisiae, also known as Brewer's yeast, is primarily used.
3. What are the examples of distilled alcoholic beverages?
Common examples include Whisky, Brandy, Rum, Gin, and Vodka.
4. What is the limit of alcohol concentration in non-distilled beverages?
The natural limit is about 13-15%, as the alcohol becomes toxic to the yeast cells and stops the fermentation process.
5. What is Brewer's yeast?
It is a strain of Saccharomyces cerevisiae used specifically for fermenting sugars into ethanol for the beverage industry.
6. Is wine a distilled or non-distilled beverage?
Wine is a non-distilled beverage produced by fermenting fruit juices, mainly grapes.
7. What raw material is used to produce Rum?
Rum is produced by the distillation of fermented sugarcane juice or molasses.
8. What is the role of fermentation in the beverage industry?
Fermentation is the process where yeast converts sugars into ethanol (alcohol) and CO2 under anaerobic conditions.
9. Why does whisky have more alcohol than beer?
Because whisky undergoes distillation, which concentrates the alcohol and removes water, whereas beer is only fermented.
10. Are cereals used to make alcohol?
Yes, malted cereals are the primary raw material for making beverages like beer and whisky.