Fermented beverages

1. FERMENTED BEVERAGES –BEER
Submitted by
M.Reshma
II.M.sc., Microbiology

2. Contents:
• Beer-Introduction and definition
• History of beer
• Beer composition
• Brewery process
• Types of beer
• Factors affecting beer quality
• Top companies involved in beer production
• Worldwide impact of brewing industry
• Benefits and disadvantages of beer
consumption

3. Beer-Introduction
• The BEER gets its named from Anglo Saxon word called BEER means
Barley.
• There is evidence that brewing process was established in Babylon
in 6000 B.C. Egyptian improved upon the process and Roman started
its first commercial production. The term BEER covers drink like
lager ale ,stout etc.The addition of HOPS started in the middle of 6th
century.

4. BEER- DEFINITION AND ITS HISTORY:
• Beer is defined as a fermented, alcoholic beverage made from barley,
wheat, rice,potato and flavoured with HOPS .
HISTORY:
• 4000BC – in the middle east,the sumar people were fermenting a form of
bread to make a fermented pulp which had an intoxicating effect.
• 3000BC– The early beer was cloudy and unfiltered and was usually drunk
through a straw to avoid drinking the solids from the brew, which could
be very bitter.
• 1550BC– the Egyptians were also keen brewers.Beer and malt have been
found buried in the tombs of the Pharaohs to provide sustenance for the
afterlife.

5. History: ( contd..)
• The middle ages: the largest brewers were the monasteries.
• From 1000AD: Most beer was bittered with wild herbs.
• From 1150AD: the addition of hops slowly spread throughout Europe
reaching Britain by the middle of the 15th century.
• The Reinheitsgebot (German Purity Law)of 1516: The law stipulated that
beer could only be brewed from water ,hops, and malt and that the use
of yeast would come later,after after it had been identified as the
organism responsible for fermentation.
• The Free Mash Tun Act of 1880: The new law enabled ‘ the brewer to
brew from what he pleases and have a perfect choice of his materials and
methods.

6. History: (contd)
• 1882- 1895: Louis Pasteur,a French scientist, discovered that there were
different types of yeasts that could be used in different types of fermentation
hence producing distinct beer flavours.
• Today: Beer occupies the 1st ranking order in terms of the mostly consumed
alcoholic drink around the world.
BEER COMPOSITION:

7. Water:
• Make up 90 percent of volume of beer.
• It is obtained from well or spring or tap water might also be used .
• Its purity is maintained to obtain good beer.
• Its salts and minerals contents is monitored and adjusted.
• If water contains too much of sulphur ,the brew becomes bitter.
• Malt:
• Sugar coming from malted grains such as barley,wheat ,oats, maize and rice
.
• Soaking of grains in water allow germination amd enzymes activation.
• Conversion of starch and proteins into sugars and amino acids (malting).
• Heat drying of grains to deactivate enzymes.
• Enzymes produce maltose sugar which is boiled with hops and yeasts to
produce beer.

8. Barley:
• Mainly the barley (Botanical name: Hordium
vulgare) is used but can be produced from
wheat,rice combination of grains.
• The small amount of grain added along with
the barley is termed as ADJUNCTANS.
• Adjunct can be added up to 35 percent but
higher the adjunct,lower cost,body and flavour.
• German beer are made from 100percent barley
and production process is governed by law
enacted in year 1909 called REINHEITSGEBOT
means PURITY COMMAND.

9. Hops:
• Are cone like flowers Obtained from the Hop vine
plant.
• Grows in regions like North America, Europe and
Asia.
• Humulones found in lupulin:
1. Gives the beer it’s bitterness.
2. Increases the beers shelf life.
• Hops contains resins and oils
1. The resins gives bitterness to the beer.
2. The oils enhances the flavour and aroma of the
beer.

10. Yeasts:
• Are unicellular microorganisms.
• Convert sugars into alcohol and carbon
dioxide.
• Are added after water and malt
altogether is boiled and cooled.
• Two types of yeasts are usually used :
1. Ale yeast ( Saccharomyces cerevisiae)
2. Lager yeast (Saccharomyces uvarum)

12. Brewing –defintion:
• The production of beer is called brewing.
• Which involves the fermentation of starches,mainly derived from
• Cereal grains-most commonly malted barley.

13. Brewery process:
1. Malting:
• The grains are soaked in water tanks for 2-3 days
at 10-15°C (steeping).
• They are allowed to germinate for 6-15 days
(humidity:45 percent, temperature:12-21°C)
• Enzyme cystase converts insoluble starch to
soluble starch.
• Enzyme diastase converts the soluble starch into
sugars.
• Conversion of starch into sugars (maltose)is
known as malting.
• The malt is then hot air dried at about 55°Cin past
houses.

14. MILLING:
• After drying and heating ,the rootlets from the malt is
removed.
• These malt culms are then sold to provide feed for
cattle.
• The grains are then grinded coarsely in roller
mills,forming grists.
• MASHING:
• The grist is mixed with hot water.the mash is cooked
for upto 6hours at low temperature.
• Enzymes in the malt convert startch into sugars
producing wort.
• The wort is then boiled for about an hour and a half.
• Factors like: temperature,time and ph is adjusted.

15. • LAUTERING:
• Refers to the seperation of wort (sugar solution) from
the undissolved part of the grain.
• Water is sparged through the grains.this process is
done in tanks is known as lauter tun which contains a
giant sieve.
• BOILING:
• The wort is then transferred into boiling tanks
(kettle).
• Hops are added at this stage.
• Boiling:sterilizes the wort,inactivates
enzymes,coaglulates proteins present and forms
flavour compounds from added hops.
• Hops and precipitated proteins are separated from
wort after boiling is done.
• Resulting liquid is cooled in a plate heat exchanger to
the fermenting temperature.

16. • HOP SEPARATION AND COOLING:
• Proteins and hops are then removed from the wort.
• The wort is oxygenated during cooling.
• The wort then goes to the hot wort tank.
• It is then cooled in a plate cooler where the coolant
flow in opposite direction to the wort.
• The wort’s temperature drops from boiling to about
10-20°C in a few seconds.
FERMENTATION:
• Fermentation is a process which convert sugar into
alcohol and CO2.
• CO2 stored in a different tank.
• This process takes 7-14days.
• During the fermentation a thick layer of yeast is
formed which protects the beer.

17. Vessels used: square open or conical
The Function of the fermentor:
• To contain a maximum amount of wort.
• To allow evacuation or collection of carbon dioxide.
• To have a proper cooling system.
• To monitor pH and pressure inside vessel.
• Fermenting temperature depends on yeasts being used.
• Antifoam agents used when foam production is high.
• At the end of the fermentation, the yeast is removed and saved for reuse in
the next batch.

18. Four main factors affecting the rate and quality
of beer fermentation:
• Fermentation temperature.
• Volume of yeast used at the start of fermentation.
• Volume of oxygen in the wort at the start and during
fermentation.
• Level of nutrients in wort.

20. • LAGERING:
• LAGERING: storing and conditioning stage of beer.
• Beer is kept about 0°C in stainless steel tanks after fermentation has
occurred.
• Beer is stabilized and matured to produce desired flavour.
• It is either pasteurised or filtered once or twice before bottling.
• This process takes 1-3weeks or months depending on the type of beer
produced.
• BOTTLING AND PRESERVATION:
• Packaging done in : bottles, cans and barrels.
• The container is kept free of oxygen.
• The beer is then pasteurized.
• This kill the remaining yeasts.
• Beer can also be preserved using special microfilters.
• When bottling ,the beer is also subjected to carbaonization process.

23. Real ale and pale ale:

24. Stout and Mild ale:

25. Wheat and Lager:

26. Factors affecting beer quality:
• Activity of yeast cell during fermentation influence character of
beer.
• Factors affecting quality of beer produced:
• Non fermentable components: have an impact on the medium.
• Fermentable sugars: converted also to some
• Inner yeast cell released components: released from the yeast cell
when it is inactive.
• Surface active components: adsorbed into the yeast cell wall
• Contamination: has huge impact on fermentation.

27. Top companies involved in the beer
production:

28. Worldwide impact of brewing industry:
• Global consumption of BEER- increased significantly these last 10
years.
• In US only, more than 424,000 jobs,with more than 115,000 jobs
directly at breweries and prewpubs are provided.
• Scientific claiming: the price of beer is likely to rise die to climate
change that affect production of grains.

30. Benefits and drawbacks of beer consumption:
Benefits:
• Provides vitamins,minerals and flavonoids.
• Lowers risk of coronary heart disease (CHD).
• Helps produce good cholesterol.
• Reduces risk of kidney stones.
• Reduces sensitivity to insulin.
• Strengthens the immune system.
• No significant relationship with weight gain and beer consumption.

31. Disadvantages of beer consumption:
• Impairment of driving –related skills and slow reaction time.
• Damage of organs.
• Increase risk of cancer.
• Withdrawal symptoms.
• Heart burn.
• High blood pressure.
• Intoxication
• Dehydration.