Beer Production

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					Processing Line in Food Industry

  Beer Production

                         Nuno Trindade; 2008
Raw Materials
  Malt is one of the main ingredients
and is obtained from barley, which is
            subjected to a process of
        germination under controlled
   conditions. This operation (called
 malting) causes, towards the end of
          the production process, the
 development of carbohydrates and
      nitrogenous substances by the
          enzymes formed during the
                germination process.
        Varying conditions during the
  malting process (temperature and
   humidity) allows different types of
 malt to be obtained, giving different
    colours and flavours to the beer.
Other unmalted cereals
          Of the unmalted cereals
          normally used, corn is very
          common; the oils are
          extracted, then it is milled and
          called grits. Barley, rice or
          wheat may also be used.
          These cereals are used to
          reduce the percentage of
          proteins in the wort. Unmalted
          cereals give the beer a lighter
          colour and specific
          characteristics according to
          the type of cereal chosen.
          Hops (humulus lupulos)
  The hop (humulus lupulos) is
an aromatic plant that gives beer
      its flavour and bitterness. It
 contributes to the formation of a
 good froth and protects the beer
         against contamination by
microorganisms. Today, extracts
           from this plant are used
   industrially, obtained in such a
  way as to preserve its qualities.
    Hop varieties are classified in
  terms of bitterness and flavour,
      which vary according to the
    amount of resin and essential
                  oils they contain.
Production Process
         Preparing the Wort

    The first phase in the process of beer
production is the preparation of the wort. This
           process has four stages:
    Milling: In     Mashing: The flour from the cereals
 order for the     (malt and other unmalted cereals) is
 components        mixed with water and subjected to
 to be rapidly     certain processes to obtain a wort of a
extracted and      suitable composition for the kind of
   converted,      beer being produced (varying times,
    the malt is
       milled to   temperatures and PH). These
obtain coarse      conditions encourage the development
     flour. The    of complex starch molecules and
           other   proteins in other simpler ones by
  cereals are      means of enzymes formed during the
also milled to     production of the malt. Mashing lasts 2
        varying    to 4 hours and finishes with a
      degrees.     temperature of approximately 75 ºC.
   Filtration of the wort: After mashing, the whole volume is filtered in
  order to separate the spent grains (which is an excellent animal feed)
 from the wort itself. This is done by passing water through the mash at
the right temperature in a filter press or lauter tun, which lasts around 2-
             3 hours, conducted at a temperature of 75-80 ºC.

 Boiling the wort: The diluted and filtered wort is boiled for around 2
  hours. Hops are added at this stage. The purpose of boiling is to:
      Transform and make soluble the bitter substances in the hops;
               •Eliminate undesirable volatile substances;
                            •Sterilise the wort;
      •Provoke the precipitation of proteins of high molecular weight;
                •Establish the final concentration of wort.

After boiling, it is necessary to separate the precipitated protein and the
insoluble hop components from the hot wort. Separation may be carried
 out in a decanter using gravity or with centripetal force in a "whirlpool".

Before the hopped wort goes into the fermentation tanks, it is cooled to
     a temperature of around 9 ºC and aired in sterile conditions.

During fermentation, the wort sugars are converted by the
transformation of yeast into alcohol and carbon dioxide.
Fermentation begins when yeast of a culture selected for the
type of beer being produced is added to the cooled oxygen-
saturated wort.
Fermentation takes place at controlled temperatures and lasts
around 7 days. At first it is quite violent, then slows down
gradually until the yeast is deposited on the bottom of the tank.
     Maturation, the     The next
          phase after    operation is
 fermentation, is the    stabilisation.
  period in which the    This consists
   beer is allowed to    of letting the
      rest at suitable   beer stabilise
     temperatures in     at
         order for the   temperatures
 undesirable volatile    of between
 components, which       0ºC and - 2ºC,
might affect the final   to permit
    «bouquet» of the     colloidal
beer, to be released.    stabilisation.
     Clarification of the Beer

Clarification is the operation that gives the beer its clear
limpid quality, eliminating the last remaining traces of
clouding still in suspension. It consists of pumping the
liquid through a suitable filter. The filtered beer is then
stored in tanks, now ready to be bottled.

The final stage of the beer production process is transferring
the beer into different kinds of containers (bottles, barrels, cans
Before or after bottling, the beer needs to be biologically
stabilised. This operation may be carried out cold (sterilising
filtration) or hot (using pasteurisation, which may be done either
immediately before - flash pasteurization - or after the drink is
introduced into its container - tunnel pasteurisation). At the
bottling stage, the beer is inserted into different forms (bottle,
barrel, can etc) to enable it to be appreciated with moderation.
Raw Materials   Preparation      Transformation




                      and                                              Yeast
     Yeast            Maturation

Mill           Fermentation

Mashing        Clarification

Filtration     Bottling

Wort Boiling          Wort Production