Enzymes play an important role in brewing beer. During the mashing process, enzymes from malted barley break down starch into fermentable sugars. However, commercial enzymes from other sources can supplement the malt enzymes to improve efficiency, allow use of cheaper adjuncts like barley, and optimize the brewing process. These exogenous enzymes are added at various steps like mashing, fermentation and maturation to speed up production, increase capacity and consistency, and produce beers with unique flavors not possible using just malt enzymes. Their use has grown in the brewing industry as a way to cut costs and adapt to changing raw material availability and prices.

2.  Enzymes work the same way as catalysts do, they can work with only one substrate and they can be
used more than once.
 Enzymes have a structure that is called active site. Only one substance can fit into the active site to be
digested, and it is the only substrate that this particular enzyme works with.
 The figure above shows the function of enzymes:
 The substrate enters the active site of the enzyme.
 The reaction takes place.
 The substrate exits the enzyme as two simpler products.
 You can also think of the way enzymes work as a key and a lock, the key is the substrate and the lock
is the enzyme. The key should be exactly the right shape to fit in the lock, so does the substrate to fit in
the active site of the enzyme. The key could only open only one lock, and the lock could be unlocked
by only that key.
 Enzymes are two types, Builders and Breakers. Builder enzymes do the opposite of breaker enzymes.
Breakers break large molecules into smaller simpler ones, builders combine smaller ones to make large
molecules.
 Breaker enzymes are used in the digestive system to break down large insoluble molecules into simpler
soluble ones to be used by the body. They are also present in cells that respire to break down sugars
and oxygen into carbon dioxide, water and energy. Builder enzymes are present in plants to be used
in photosynthesis, the opposite of respiration, in photosynthesis, oxygen and water are combined
together to form carbon dioxide and sugars.
 Naming enzymes depends on the substrate they work on. For example:
The sucrase enzyme works on sucrose.
The maltase enzyme works on maltose.
 Enzymes are reusable and are only affected by the change in temperature and pH

3.  A catalyst is a substance that speeds
up the chemical reaction without
getting used up or altered.
 Are proteins by nature.
 Functions as biological catalyst.


6.  Affect of temperature on the enzyme’s activity:
 Each enzyme has an optimum temperature, this is the temperature at
which the enzyme is most active, below this temperature the activity of
the enzyme decreases until it becomes inactive at low
temperatures, above this optimum temperature the enzyme becomes
denatured and can no longer work.
 At low temperatures the enzyme is and the substrate are moving very
slowly and collide weakly, the enzyme is said to be inactive and doesn’t
work. As the temperature increases, the enzyme and substrate gain
more kinetic energy and move faster colliding more, the enzyme
becomes more active and the reaction takes place. When the enzyme
reaches it’s optimum temperature, it is in its most active mood, if the
temperature crosses the optimum the enzyme begins to die and
become denatured. The enzymes become denatured when the shape
of their active site changes as a result of high temperature, thus the
substrate cannot fit into the active site and the enzyme is useless.
 Each enzyme has its own optimum temperature, enzymes in humans
have optimum temperatures of around 40 degrees. Plants have
enzymes with optimum temperature of about 25 degrees.

8.  As in temperature, enzymes have an
optimum pH. The pH is a scale measuring
the acidity or alkalinity of a substance or
solution. The scale runs from 1 to 14. pH 7 is
neutral, below that it is acidic and above
that it is alkaline.
 Each enzyme has an optimum pH, if this pH
changes, the shape of the active site of the
enzyme is changed, thus the substrate will
not be able to fit in it, and the enzyme
becomes useless.

9.  `Seeds grow into plants by germinating. Seed germination
involves enzymes breaking the materials stored in the seed down
to be used in growth, energy and building cells. The seed
contains stored substances such as:
 Starch: Starch is broken down by amylase enzyme into
maltose, maltose is then broken down by maltase enzyme into
glucose which is used in respiration.
 Proteins: Proteins are broken down into amino acids by Protease
enzyme, amino acids are used in building up cells and growth.
 Fats: Fats are broken down into fatty acids by lipase
enzyme, they are used in making cell membranes.
 In order for a seed to germinate, some conditions must be
present:
 Water: To activate the enzymes.
 Oxygen: To be used for respiration.
 Warm Temperature: For providing the best conditions for
enzymes to work and optimum temperature.

11.  Washing powders contain detergents that help in cleaning
clothes by dissolving stains in water. Some stains are made of
insoluble substance, these cannot be removed by normal
washing powders, instead, a biological washing powder is used.
 Biological washing powders contain enzymes that break down
the insoluble stain into smaller soluble substances, which are then
dissolved in the water.
 For example, if your shirt gets stained by egg yolk or blood, there
is an enzyme called protease in the washing powder that will
break down the insoluble protein into amino acids, which are
dissolved in the water and sucked away. Thus the shirt becomes
clean.
 The best removal of stains is maintained by providing the
optimum temperature for enzymes, presoaking to leave time for
the enzymes to digest, putting the suitable amount of the
powder.

12.  Use Of Enzymes In Food Industry:
 Enzymes are often used in the manufacturing of different foods.
 Baking – Brewing – Cheese Making:
 In baking, both yeast and sugar are used. Yeast cells contain enzymes that ferment sugar by
anaerobic respiration producing carbon dioxide bubbles which causes the dough to rise as in the
photo.
 Brewing is the process of making wine or beer. In this process fermentation is Involved producing
alcohol which and carbon dioxide that gives wine and beer its sparkle.
 In making cheese, an enzyme called rennin extracted in enzymes, helps by clotting milk.
 Making Juices:
 In fruits such as apples or oranges, a substance called pectin holds the cells together making it
hard to squeeze them. An enzyme called pectinase digests pectin making it much easier to squeeze
the fruit and to make the juice more clear than cloudy.
 Making Baby Foods:
 It is hard for new born babies to digest food such as high protein foods. That is why foods like that are
treated with proteases to break down protein to amino acids, making it easier for newborns to absorb
and assimilate them.
 Making Sugar:
 Sugar producing companies get sugar from starch by using the amylase enzyme to digest starch into
maltose. For dieters a sugar called fructose is very useful because it provides a sweater taste than
other sugars from a less quantity. Fructose can be obtained by using the isomerase enzyme to convert
glucose to fructose.
 Meat And Leather Production:
 Proteases are used to make meat less tough and acceptable for consumers by treating cuts of meat.
 In leather industries hairs are removed from animal skin by digesting them using protease enzymes.

13.  Enzymes Extraction:
 The Enzymes used in the industries are taken from either
fungi or bacteria. This takes place in a Fermenter, this is a
large sterilized container with a stirrer, a pipe to add
feedstock and air pipes.
The following steps take place:
 The micro-organisms and the feedstock are added and
the liquid is maintained at 26 degrees and pH of 5-6.
 The micro-organisms produce two types of enzymes, either
extra-cellular or intra-cellular.
 Extra-cellular enzymes are extracted from the feedstock
by filtering.
 Intra-cellular enzymes are extracted by filtering the micro-
organisms from the feedstock, crushing them, wash them
with water then extracting them from the solution.

14.  Enzymes And Antibiotics:
 Antibiotics are powerful medicines that fight bacterial infections. Micro-organisms are used for the
production of antibiotics.
 Some Antibiotics, like bactericides, fight bacteria by damaging its cell walls causing them to burst and
die. Other antibiotics interfere with the protein synthesis and stop the bacteria growing.
 Antibiotics have no effect on human cells because human cells have no cell walls and the structures
involved in protein production are different than that of bacteria.
 Antibiotics are obtained from sources like:
 Bacteria (Actinobacterium Streptomyces): this bacterium produces the antibiotic strepmycin.
 Fungi (Penecillum fungus): penicillin, the first antibiotic discovered is produced by thing fungus.
 Different types of penicillin are produced by different species of the fungus. They are chemically
altered in lab to make them more effective and make them able to work with different diseases.
 Steps of production:
 The Fermenting tank in filled with nutrient solution of sugar (lactose) or corn liquor which contain sugars
and amino acids,
 Minerals are added,
 pH is adjusted around 5 or 6,
 Temperature is adjusted about 26 degrees,
 The liquid is stirred and air is blown through it,
 The micro-organisms are added and allowed to grow for a day or two in sterile conditions,
 When the nutrient supply is decreased, micro-organisms secrete their antibiotics,
 The fluid containing the antibiotic is filtered off and the antibiotic is extracted.

15.  Even for an old industry like beer brewing new
industrial processes benefit from using enzymes
developed from microbial sources. In the last
years quality issues like flavour control, beer
stability and general cost savings in the industry
go hand in hand with efficient solutions of
environmental problems. Future aspects focus
on a wider application of enzymes to brew
with high amounts of inexpensive raw materials
like barley. Alternative beer processes for
production of wort and beer with higher
productivity and reduced amounts of waste
and by-products are under development.

16.  Introduction
 Beer and wine are both alcoholic beverages which
have been part of our social life for thousands of
years. Both beverages are produced by yeast
fermentation of sugars. Wine is based on grapes, and
beer is traditionally based on barley. The matured
grapes already contain the sugars needed for the
fermentation, while barley contain starch that has to
be broken down to fermentable sugars before the
yeast can make alcohol. Therefore, traditional
brewing contains and extra step compared with
wine-making, namely malting in which enzymes
needed for the degradation of starch into
fermentable sugars are produced.

17.  Malt is germinated barley or other cereals like
wheat and sorghum: First the grains are
"steeped" bringing the water content from
about 12% to 45%, then they are allowed to
germinate for 4-6 days and finally the
germination is stopped by heating (kilning)
reaching a final moisture content of about 4%.
Some enzymes are already present in the
barley, e.g. β-amylases, but the majority of
enzymes are produced during the
germination, e.g. α-amylases and
proteases, and in the final malt all the enzymes
needed for the conversion of "grains" into a
fermentable liquid (wort) is present (Figure 1
and 2)

18.  In former days, production of malt was an integrated part of every brewery, but to day
most malt is produced outside the brewery in large malt factories, and malt has
become a purchased raw material, like other raw materials. This means that the
breweries to day are more flexible in the use raw materials, and for that matter for the
source of enzymes.
 The malt enzymes do have some limitations. They can only work at certain
temperatures, pH values etc., and the activities might be too low to do a proper job in
proper time. In contrast, commercial exogenous enzymes can be designed to work at
preferred temperatures and pH values, to have more enzymatic power, or to express
wanted enzyme activities that are not present in malt. Addition of exogenous enzymes
at various steps during the brewing process can therefore make brewing easier, faster
and more consistent. It gives the brewmasters extra flexibility in the choice of raw
materials due to less dependence on malt enzymes, as well as providing opportunity to
create new products, which is not possible to make with malt enzymes alone. Also the
possibility to improve beer quality by avoiding off-flavours is possible with commercial
enzymes. The increasing concern on resources and CO2- emission has also put the use
of commercial enzymes within the brewing industry in focus. By the use of exogenous
enzymes more can be extracted from the raw materials, more local raw materials can
be used, and more unmalted grains can be used, saving significant amounts of energy
and transport

19.  The brewing process
 Traditionally, beer is produced by mixing crushed barley malt and hot water in a mash copper to
perform the mashing. Besides malt, other starchy cereals such as maize, sorghum, rice and barley, or
pure starch itself, can be added to the mash. These are known as adjuncts.
 The standard mashing for pilsner type beer consists of several temperature steps, each favouring
different malt enzyme activities. The lowest temperature (45 ºC) is the optimal temperature for cell wall
degrading enzymes, β-glucanases. The proteases works best at 52 ºC, the β-amylase best at 63 ºC and
the α-amylase at 72°C. The last step in the mashing is inactivation of the enzymes at 78 ºC (Figure 3).
 Figure 3: The traditional mashing temperature profile is determined by the temperature optima for the
various malt enzymes. Larger version
 If β-glucan and protein are properly broken down during malting, single temperature mashing at 65-
71°C has shown to be sufficient, as in the case of traditional ale brewing.
 During mashing the starch is degraded to dextrin and fermentable sugars. α-amylase liquefy the
gelatinized starch by hydrolysis of the α-1,4 linkages at random. β-amylases are exo-enzymes which
attack the liquefied starch chains resulting in successive removal of maltose units from the non-
reducing end.
 After mashing, the mash is sieved in a lauter tun or on a mash filter. The resulting liquid, known as sweet
wort, is then transferred to the copper, where it is boiled with hops. The hopped wort is cooled and
transferred to the fermentation vessels, where yeast is added. In normal wort 2/3 of the carbohydrates
are fermentable sugars. After fermentation, the so-called ‘green beer' is matured before final filtration
and bottling. Fig. 4 shows a diagram of the brewing process and where external enzymes are used for
process aids.

20.  Commercial enzymes from exogenous sources
 The traditional source of enzymes used for the conversion of
cereals into beer is barley malt. If too little enzyme activity is
present in the mash, there will be several undesirable
consequences: the extract yield will be too low; wort separation
will take too long; the fermentation process will be too slow; too
little alcohol will be produced; the beer filtration rate will be
reduced; and the flavour and stability of the beer will be inferior.
 Exogenous enzymes are used to supplement the malt's own
enzymes in order to prevent these problems.
Furthermore, industrial enzymes are used to ensure better
adjunct liquefaction, to produce low-carbohydrate beer (‘light
beer'), to shorten the beer maturation time, and to produce
beer from cheaper raw materials.
 The various steps of the brewing operations, where microbial
enzymes are occasionally added, are shown in table 1.
Enzymes, enzymic action and their functions are summarized.

21.  Enzymes at work
 Quality and supply constraints on malt, and doubling of malt
prices have given increased interest for enzyme solutions in 2007
and 2008. Many breweries has run programs within the last two
years in order to increase efficiency and optimize raw material
usage, and many of them have focused on commercial
enzymes to shorten the production time, increase capacity, and
to allow use of raw material alternative to malt. Three important
examples are mentioned:
 Exchanging part of the malt with barley has been popular
because using barley in combination with commercial enzymes
gives the same beer quality as with malt.
 Introducing a higher content of starch hydrolysing enzymes offer
the possibilities of producing "light beer" also called "low calorie
beer".
 An enzyme solution for diacetyl control after fermentation
improves vessel utilization, save energy and ensures a high beer
quality after a reduced maturation time

22.  Enzymes to improve fermentation
 Small adjustments in fermentability can be achieved by adding
amyloglucosidase alone or in combination with debranching enzymes
at mashing-in or a fungal α-amylase at the start of fermentation.
 To describe to which extent the extracted sugars are fermentable
brewers define degree of attenuation, which is synonymously with
degree of fermentation or fermentability.
 Figure 6. Total fermentable sugar production with different dosages of
Attenuzyme® (kg per ton malt) and extended mashing at 63°C
 Beer types with very high attenuation ("light beer" or "low calorie beer")
are most often produced using amyloglucosidase alone. Extended
mashing at 63°C and high dosages of enzymes is necessary to produce
extremely high attenuated beer (see figure 6).
 Fungal α-amylases are used to produce mainly maltose and dextrins
whereas amyloglucosidase produces glucose from both linear and
branched dextrins