Note: Descriptions are shown in the official language in which they were submitted.
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The present invention relates to the field of brewing.
More specifically, the present invention pertains to a
process for monitoring and controlling the lautering process in
brewing, thereby to economize the brewing process and optimize the
quantity of brewed alcoholic beverages obtainable from a given
quantity of starting materials.
To brew beer (which will in the disclosure and claims
appended hereto mean any brewed alcoholic beverage including ale,
lager, stout, porter, neutral brewed alcoholic beverages and so
on) one begins with water, barley and optionally, other cereal
adjuncts. The barley is first malted; that is, it is permitted to
germinate so that the naturally occurring enzymes of the barley
convert the starch in the barley into fermentable or non
fermentable sugars. The thereby obtained malt i5 then ground and
mixed with water which has been purified and treated, as is known
generally in the brewing art, to obtain the proper chemical
balance ~or brewing beer. The other cereal adjuncts may be added
at this time. These adjuncts include corn and rice.
The mixture of water, ground malt and cereal adjuncts,
known as mash, is heated to obtain a wort, which is a solution of
water and solids extract. The wort is then transferred to a
lauter tun which is a large generally cylindrical vessel with a
false bottom which is provided with an abundance of perforations
so that the solids can settle while extractable solids are
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extracted from the wort. This process of extraction of wort i5
known as lautering.
The wort is then withdrawn from the lauter tun, via a
system of piping which draws solution from a number, typically
three, approximately equal zones in the tun. Taking a three~zone
tun as an example, zone one is the centre of the tun, zone two is
the middle band surrounding zone one, and zone three extends
around zone two, about the periphery of the tun~ For each zone,
there is a circle of piping underneath the false bottom.
The concentration of extract of the solution which is
drawn from each zone is monitored as the solution is drawn from
the tun and transferred to a wort kettle. This is because it i5
essential to know when all o the extracts which can practicably
be obtained from the mash have been obtained. After most of the
wort solution has been withdrawn from the tun, the malt is rinsed,
or sparged, with sparge water which is showered into the tun to
dissolve as much extract of the malt and cereal adjuncts as
possible.
As the concentration of extract of the solution which is
O withdrawn decreases, maximum yield of sugar and other extractable
solids in the solution withdrawn is obtained by ensuring that the
solids content in the solution drawn from each zone is as nearly
equal as possible. Accordingly, as the wort solution is withdrawn
from the lauter tun, its concentration of extract, in degrees
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Plato, i~ checked with a saccharameter on a zone by zone basis.
The process of checking with a saccharameter takes about ten
minutesj because a quantity of the warm solution must be tapped by
hand into a vessel, and then cooled to 20C before it is checked.
If it is found that the solution from a zone is of a relatively
low density, the sparge water will be given greater residence time
in that zone to increase the sugar and extractable solids content
thereof~ Thi~ is e~sentially a hit and mi~ procedure which
depends for its success upon the skill and experience of the
LO brewmaster. Generally, a good run using this technique will
result in a final sugar content of about ~.5 to 3.0~ Plato before
the ground malt and cereal adjuncts will be considered to be
exhausted of solids which are economically obtainable.
The object of the present invention is to provide a method
and apparatus of obtaining a much greater yield of sugar and other
extractable solids from mash in the lautering process. It has
been found that using the present invention, a final solids
content of 1 Plato can be obtained on a f airly consistent basis.
In one broad aspect, the present invention relates to a
method for monitoring and controlling the e~tractable solids
concentration of wort in a brewing process, including the steps
of: ~a) introducing a mash including ground malt and water into a
lauter tun having a least two concentric extraction zones, there
being extraction pipes for extracting wort from each of said zones
in said lauter tun; b) extracting saccharified wort from said
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lauter tun, via said extraction pipes from said zones, said pipes
leading to a wort kettle, and adding sparge water to said lauter
tun as said wort is extracted to extract further solids from said
ground malt; c) monitoring the extractable solids in the
extraction pipe from each said zone by sequentially passing
samples of wort from each said pipe via sampling lines, through a
densimeter, to obtain density readings of the wort from each said
zone; and d) adjusting the flow of wort from the extraction pipe
from each said zone in response to said density readings by
automatic flow adjustment means in said extraction pipes to obtain
a flow of wort in each said extraction pipe having app.roximately
the same extractable solids concentration.
In another broad aspect the present invention relates to an
apparatus for monitoring the quantity of extractable solids
extracted during lautering in a brewing process, including:
(a) sampling lines connected to extraction pipes leading from .. :~
concentric zones of a lauter tun; (b) a densimeter connected to
said sampling lines, for determining density, and thereby the
extractable solids content of the wort in each said extraction
pipe; tc) flow adjustment means in said extraction pipes; and
(d) means for automatically adjusting said flow adjustment means
~c) depending on the reading of said densimeter (b) to obtain an
approximately equal extracted solids content in each of said
extraction pipes.
In drawings which illustrate, by way of example, the
present invention:
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Figure 1 is a schematic of a lauter tun piping system
embodying the present invention;
Figure 2 is a side view of the densimeter used in the
present invention; and
Fiyure ~r is a top view o~ the densimeter used in the
present invention.
Referring to Figure 1, it will be seen that small pipes
11,12,13, lead from each of the three zones 1,2,3 of the lauter
tun 4 (indicated generally) to a densimeter 5. It will be
understood specifically that a three zone lauter tun is described
herein for illustrative purposes only. It will be clear that the
present invention is equally workable on lauter tuns having any
number of zones.
These small pipes 11,12,13 are branches from large pipes
or "zone lines" 21,22,23 which lead to the wort kettle 5
(generally). Downstream (i.e. toward the wort kettle) o the
point at which each small pipe branches off of the large pipe,
there is an electronically controlled zone valve 31,32l33. By
varying the degree to which each valve is opened, the relative
quantity o wort extracted from each zone can be varied.
The total quantity of wort flowing through the main valve
7 to the wort kettle will, of course, be 100~ at any given time,
so the quantity flowing through any of the three zone valves
31,32,33 can be expressed as a portion of 100, with the total
flowing through the three valves equalling 100.
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~ s the malt and cereal is sprayed with sparge water, and
wort is drawn out of each o~ the zones 1,2,3 of the lauter tun by
zone lines 21,22,23, small valves (the general locations indicate~
at 41,~2,43) in each o~ the three small or "monitoring" lines
11,12,13 will open and close in sequence, permitting wort ~rom a
particular zone, one, two or three as the case may be, to flow
through the densimeter 5 and to the main llne leading to the wort
kettle 60
After the wort from one zone has flowed through the
densimeter 5 so as to flush out the wort from the zone previously -~
flowing through same (a process which takes about 45 seconds to
ensure that only wort from a given zone is present) a reading from
the densimeter is taken for about 15 seconds, to very accurately
gauge the extracted solids content of the wort from a zone.
Depending on the reading taken, the corresponding zone valve
31,32,33 will be opened more or closed more either to withdraw
more wort, if the density reading in a zone is higher than the
other zones, or to withdraw less wort (and thereby give the sparge
water more residence time to take extractable solids into
solution) i~ the reading in that ~one is lower than other zone.
As the density readings are checked, zone by zone, one
zone per minute, the extracted solids content in each zone can be
kept at very consistent levels. Beariny in mind that all sparge
water that is sprayed into the lauter tun must be withdrawn, the
present invention thereby ensures that no solution is withdrawn
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which is practically devoid of extracted solids. Also, no wort
with acceptable extracted solids content will be left in the
lauter tun, as was often the case previously if a quantity of very
low density wort was, because of the time necessar~ to take
readings, allowed to fill the wort kettle. However, if it does
happen that after the wort kettle is full, appreciable qu~ntities
of wort can still be withdrawn from the lauter tun (and this will
happen, because of the economy of the present invention) this
"sweet water" solution can be kept in a holding tank and added ~o
the next run in the lauter tun. Alternatively, a larger wort
kettle (meaning a greater quantity of end product beer) can be
used. Either of these two possibilities was un~easible with the
prior method o~ checking sweetness by hand, because of the time
involved and the undesirability of obtaining and storing from a
zone, water with practically no extracted solids, even though soma
solids could be extracted from the other zones. Such extraction
would have tied up equipment and labour for too long a time.
As noted above, the present invention utilizes a
densimeter 5. A suitable densimeter is a DENS-ELI~, made by Valmet
Instrument Works of Tampere, Finland. To the best of the
Applicant's knowledge, a densimPter has never before been used in
a process like that of the present invention. A thorough
description of a DENS-EL~ is to be found in the technical
specifications for same, available from Valmet Instrument Works.
A brief discussion of the device, relevant to the present
invention, follows.
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The DENS-EL~ is an electronic density transmlt~er
operating on the force-balance principle. Referring now to
Figures 2 and ~a, the DENS-EL~ density transmitter is a balance
comprised of a U-tube 51 through which the wort flows. The U-tube
is hingedly connected, via a bellows 52, to a main body 33. The
U-tube moves about an axis. Change in the density of the wort
flowing through it (which will be caused by a change in the
extracted solids content of the wort) causes a change in the
vertical forces acting on the tube, causing it to move about its
axis. This vertical change is electronically measured and
transmitted to a central processing unit, which converts the
reading from the densimeter to a measurement in degrees Plato of
the sweetness of the wort passing through the tube. This
measurement is compared to the latest measurement of the sweetness
of the wort from the other zones, and -the zone valve 31,32,33 of
the zone line from which wort is being drawn fractionally or
wholly opened or closed accordingly.
It will be understood, then, that each of the three zone
line valves is controlled by the central processing unit which
receives the readings from the densimeter.
It will further be noted that a temperature compensator
is installed in the densimeter. This is basically a tensioning
line attached to the U-tube. As the densimeter reads the
temperature of the warm wort passing through it, the tension of
this line is increased or decreased accordingly, so that a true
reading of the sweetness of the wort can be made, regardless of
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the temperature thereof. In this way, a fur-ther draw-back of the
prior art method of lautering (i.e. sugar ex*rac-tion) - that of
having to cool the wort before each measurement - is obviated.
It is to be understood that the methods and apparatus
described above are not meant to limit the scope of the present
invention. It is expected that numerous variants will be obvious
to the person skilled in the brewing art, without any departure
from the spirit of the present invention. The appended claims,
properly construed, form the only limitation upon the scope of the
present invention.
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