The Brewing Process – how to make beer
Following the schematic above, the first process that takes place is milling of the malted barley.
After this initial step, the milled barley is mashed. After mashing, water is added and the mixture is
put through a process called lautering. The lautered mixture is then boiled. After boiling, hops are
added. These hops are then put through the whirlpooling process and then cooled. Once cooled, yeast
is added to begin the process of fermentation. After fermentation the yeast is removed and the
beer is allowed to mature. After filtering, the beer is ready for the bottler and subsequent
distribution.
This process is by no means an exact recipe. Many different breweries change the process for their
own needs. By doing so, they are able to create unique beers which can be enjoyed by a diverse group
of people. Even if the nuances are different, the main ingredients usually stay the same. The staples
of good beer are Barley, Hops, Water, and Yeast.
Making beer
Beer is an alcoholic drink made by fermentation reactions that use yeast to convert sugars into
ethanol. There are harmful effects and social problems because of ethanol in drinks.
Ethanol is the type of alcohol found in alcoholic drinks such as wine and beer.
Structure of ethanol formula
C2H5OH
Sugar from plant material is converted into ethanol and carbon dioxide by fermentation. The enzymes
found in single-celled fungi - yeast - are the natural catalysts that can make this process happen.
Here are the word and balanced formulae equations:
glucose
→
ethanol + carbon dioxide
C6H12O6 - (enzymes in yeast)--> 2C2H5OH + 2CO2
Fermentation usually works best at around 37ºC. It is a slow process and several weeks or more are
usually needed to produce an acceptable alcoholic drink.
The sugars for beer-making come from boiling barley in water. Hops are added to adjust the flavour
of the beer.
Problems with alcoholic drinks
Ethanol is a depressant - it slows down signals in the nerves and brain. Small amounts of alcohol help
people to relax, but greater amounts lead to a lack of self-control and loss of judgement. Drinkers
may put themselves in dangerous situations, and may not realise how much they are drinking. They
may fall ill, or become unconscious.
Ethanol is also toxic. Yeast are actually killed by the ethanol they produce. Long-term effects of
drinking excessive amounts of alcoholic drinks include damage to the liver and brain. It may also
cause weight gain, and is addictive.
People have been making beer for more than 8,000 years. Today brewers use science to help them to
improve the production process.
Beer is made using fermentation. Fermentation converts the glucose (a sugar) into alcohol and carbon
dioxide.
The fermentation reaction needs enzymes to make it go fast enough. A microscopic fungus called
yeast is added when you are making beer. The yeast makes the enzymes for the fermentation
process.
To make beer, the brewer mixes malted barley grains with warm water. Later, hops are added and
the liquid mixture of malt, hops and water (called a wort) is boiled. After heating, the liquid is then
cooled. It is run into the fermenter and the yeast is added. After a while, the air in the fermenter
runs out. This is necessary for fermentation. The yeast has all the conditions it needs to grow,
including a supply of glucose and a suitable temperature. The temperature is usually kept between 15°
C and 25° C. These are the temperatures at which the yeast´s enzymes produce the best beer. If
the fermentation temperature is too low, the enzymes will be inactive, if it is too high, the enzymes
will be destroyed. No fermentation reaction can take place above 55 C. The fermentation stops when
the glucose sugar runs out. The brewer then lets the beer mature and after that puts the beer into
barrels or bottles.
Tasks:
1. What is the main process the produces beer called?
2. List the conditions that yeast needs for fermentation.
3. What are the chemicals found in yeast that speed up the fermentation process?
4. What are the four main ingredients to make beer?
5. What is the chemical formula of glucose and ethanol?
6. What is yeast?