Grains Intake
/Pre –Treatment
There are two separate intake pits; one for the intakes of malt while the other is for
adjunct (raw/malted sorghum and maize grist). The grains are discharged into
the intake pit, which has a chain and a screw conveyor connected to its base,
these conveyors transport the grains horizontally through a magnet (removes
metallic objects from the grains). It is then conveyed to a drum sieve for
bigger object to be removed. From the drum sieve, the grains move downward to
the screen sieve shaker for object smaller than the size of the grains to be
removed. These grains are then discharged into the bucket elevator which
transport the grains vertically and empties into a chain conveyor at the top,
which then transfers the grains to
designated silo.
Storage
The per-treated
grains are then sent to their different silos for storage until the need arises
for its usage. During storage, the grains in the silos are checked for
infestation with insect and rise in temperature which is not expected to exceed
35°C otherwise the moisture content of the grains will rise beyond normal due
to rise in temperature and condensation
Treatment
When the grains
are needed for production, it will be discharged from the bottom of the silo to
the bucket elevator which conveys it upward to combi cleaner (destoner). This
machine removes stones of different sizes from the grains.
Milling
From the
destoner, it goes directly into the hammer mill where the beaters in the mill
crush the grains to smaller sizes. The discharge opening of the mill is covered
with a perforated metal screen of 2.5
mm which retains coarse materials for further
grinding while allowing the
properly sized materials to pass
through
Weighing
From the hammer
mill, the resulting grist will be
conveyed via a screw conveyor to the
weighing bin, which weighs the quantity
of the raw materials needed
The quantity of
the raw material required for one brew of maltina includes;
|
malt
|
Sorghum malt
|
Raw sorghum
|
maize grist
|
|
6 tons
|
2.4tons
|
6 tons
|
2 tons
|
Mashing
The weighed
grist is transported via a pneumatic conveyor (air blower ) into
a mashing Vessel where it is mixed with water the malt is mashed into the mash
tun while the adjunct is mashed into the mash copper and is allowed to under go protein rest, gelatinization rest, and liquefaction
rest before it is transferred into the
mash tun to mix with the malt and under go saccharification rest
together.
Mashing
Processes
The adjunct is
mixed with ambient water at about
32°c and hot water of about 85oc into the mash copper to achieve a pre mash
water of 50oc. After mashing-in into the mash copper, the
temperature is maintained at 50oc and left for 50mins protein rest
{breaking down of protein to amino-acids} at this point, Amylex is added. Here
the PH is checked and the norm should be b/w 5.2-5.6. Correction is made by
adding either lactic acid or calcium chloride. The mash is then heated up to 75oc
at 1oc rise per min. At about 73oc, mashing-in of malt
into the mash tun{MT} is done. Before the malt grist start droping into the
mash tun, lactic acid is added also PH is checked and correction {5.2-5.6} is
done where necessary. Protein rest is imposed into the mash tun at this point
too. At 75oc in the mash copper {MC}, the mash is allowed to rest
{gelatinization} for 40 Mins so as to expose the starch by liberating them from
the confines of the protein already broken down, After which it is heated to 93oc.
At 93oc, a rest (Liquefaction) for 10 mins is imposed; this makes
the starch soft and more exposed and ready for sugar conversion. The mash then
is transferred into the mash tun. Initially, the transfer is done directly and
when the temperature in the mash tun is 60oc. the transfer is done
via a cooler so as to bring the mash temperature to 66oc. Before
entering the mash tun, PH test is carried out to confirm it is between 5.5-5.7
otherwise, correction too is made. At the end of transfer, the mash is allowed
to rest {saccharification} for about 15 mins. At this point, starch is being
converted into sugar and a mash sample is taken for sacharification test.
Mash Filtration
After mashing,
the mash is pumped to a mash filter where the resulting liquid is strained from
the grains. sparge water is used to rinse the mash filter. The filtrate {wort}
is sent to the wort copper for boiling while the spent grains are sent to the
spent grain silo.
Wort Boiling
At this point,
the liquid {filtrate} is called wort. The wort is transferred into the wort
copper for boiling. During boiling, hops, sugar, caramelized dextrose maltase
{CDM}, calcium chloride {CalCl}, maltina complex is added. Wort boiling
processes serves as to;
i. Sterilize
the wort {some bacteria and moulds that could have survived the
brewing process so far are killed}
ii.
Terminate enzymatic processes
iii.
Coagulate proteins
iv.
Volatilize off flavours
v.
Isomerize hop resins {extract the
bittering substance from hops} hops gives the bettering taste to the beverages.
Wirlpool Rest
After wort
boiling, the wort will be send to a whirlpool vessel for the coagulated
proteins (trub) and other heavy materials to be separated from the wort. The
hot Wort is pumped in at an angle tangential to the whirlpool vessel. This
produces a force of in-flow that causes the trub particles to accelerate
towards the centre of the vessel. They form large flocs, which then settle down
at the center bottom line of the vessel to form a trub cone. The clarified wort
is run off from above the trub cone through senses of run off points on the
whirlpool vessel.
Wort Cooling
The clarified
wort which leaves the whirlpool around 85oC has to be cooled down to
0°C before carbonation. This is achieved by passing counter flows of cold water
against wort on either sides of the plate heat exchanger. The process of heat
transfer i.e heat loss by the wort and the heat gained by the water tends to bring the temperature down.
Filtration
The unclearified
malted drink is transferred to the KG filter for it to be filtered. As it is
moving to the KG filter, it will pass through a cooler which tends to maintain
the temperature at 00C from the cooler to a stabilizer (BK 75).
Here, the protein component of the beverages is coagulated to form bigger
particles. It is at this stage that
certain corrections like colour dosing,
hops dosing are made. It moves to the KG filter, this
KG filter contains different candle size that are coated with filter
powders (Keiselgur) to entrap the
coagulated protein particles while
it moves through a pipe to
the carbon blender for carbonation.
Carbonation
It moves from the KG filter to
carbon blender for addition of carbon (iv) oxide. O2 gives the soft
drink an appetizing taste (mouth feel)
and also increases the shelf life of the beverage. At this stage,
dilution of the original gravity (OG) is
carried out and it is done with deaerated water (DAW)
BBT Storage
The carbonated drink is send to
the BBT for storage until when the need arises it will be send to packaging
department for it to be bottled.
Packaging
When the drinks
are needed for bottling, it will be sent
from the bright beverage tank (BBT) to the bottling hall. Here the bottles are washed and inspected before they
are conveyed to the filler/crowner to be filled with the beverage. From the
filler/crowner, the bottle is conveyed to the full bottle inspector (FBI) that
inspects and removes under filled bottles, improper corked bottles from the
line. The bottles move on the conveyor to the pasteurizer where the
microorganisms are rendered inactive. From the pasteurizer, it goes to the
labeling machine where the maltina bottle is labelled then to the coding
machine that prints the production date, expiring date and batch no on the
labeled product. The labeled bottles moves on the conveyor to the packer where
they are packed into crates. From there to the full crate inspector (FCI) which
inspects and removes any crate that contains improper crating. From the (FCI),
the crate is conveyed to the palletizer where it is palletized after which it
is transported to the full bottle store where it is stored before its
distribution.