12-12-2012, 02:59 PM
Assignment on Manufacturing Process of Alcoholic Beverages
Assignment on Manufacturing.docx (Size: 1.37 MB / Downloads: 56)
Introduction
An alcoholic beverage is a drink containing ethanol, commonly known as alcohol. Alcoholic beverages are divided into three general classes: beers, wines, and spirits. They are legally consumed in most countries, The production and consumption of alcohol occurs in most cultures of the world, from hunter-gatherer peoples to nation-states.
Alcohol is a psychoactive drug that has a depressant effect. A high blood alcohol content is usually considered to be legal drunkenness because it reduces attention and slows reaction speed. Alcohol can be addictive and addiction to alcohol is known as alcoholism.
Types
Alcoholic beverages are produced by fermentation of sugar- or starch-containing plant material. Beverages produced by fermentation followed by distillation have a higher alcohol content and are known as liquor or spirits.
Beer is made by the process of fermentation. A liquid mix, called wort, is prepared by combining yeast and malted cereal, such as corn, rye, wheat or barely. Fermentation of this liquid mix produces alcohol and carbon dioxide. The process of fermentation is stopped before it is completed to limit the alcohol content. The alcohol so produced is called beer. It contains 4 to 8 per cent of alcohol.
Alcoholic fermentation reaction
Glucose---- Pyruvate---- Alcohol+ CO2
Ingredients
The basic ingredients of beer are water; a starch source, such as malted barley, able to be sac-charified (converted to sugars) then fermented (converted into alcohol and carbon dioxide); a brewer's yeast to produce the fermentation; and a flavouring such as hops.
A mixture of starch sources may be used, with a secondary starch source, such as maize (corn), rice or sugar, often being termed an adjunct, especially when used as a lower-cost substitute for malted barley.
Starch source
The starch source in a beer provides the fermentable material and is a key determinant of the strength and flavour of the beer. The most common starch source used in beer is malted grain. Grain is malted by soaking it in water, allowing it to begin germination, and then drying the partially germinated grain in a kiln. Malting grain produces enzymes that convert starches in the grain into fermentable sugars. Different roasting times and temperatures are used to produce different colours of malt from the same grain. Darker malts will produce darker beers.
Hops
Flavouring beer is the sole major commercial use of hops. The flower of the hop vine is used as a flavouring and preservative agent in nearly all beer made today. The flowers themselves are often called "hops".
• Hops contain several characteristics that brewers desire in beer.
• Hops contribute a bitterness that balances the sweetness of the malt.
• Hops contribute floral, citrus, and herbal aromas and flavours to beer.
• Hops have an antibiotic effect that favours the activity of brewer's yeast over less desirable microorganisms and aids in "head retention",
• The length of time that a foamy head created by carbonation will last. The acidity of hops is a preservative.
Yeast
Yeast is the microorganism that is responsible for fermentation in beer. Yeast metabolises the sugars extracted from grains, which produces alcohol and carbon dioxide, and thereby turns wort into beer.
In addition to fermenting the beer, yeast influences the character and flavour.
The dominant types of yeast used to make beer are the top-fermenting Saccharomyces cerevisiae and bottom-fermenting Saccharomyces uvarum.
Brewing: How Beer is Made..?
Brewing is fundamentally a natural process. The art and science of brewing lies in converting natural food materials into a pure, pleasing beverage. Although great strides have been made with the techniques for achieving high-quality production, beer today is still a beverage brewed from natural products in a traditional way. Although the main ingredients of beer have remained constant (water, yeast, malt and hops), it is the precise recipe and timing of the brew that gives one a different taste from another. The production of beer is one of the most closely supervised and controlled manufacturing processes in our society.