MXPA96004285A - Process for the continuous ebullicion of mo - Google Patents

Abstract

The present invention relates to a process for the continuous boiling of wort, which comprises feeding the wort that has not been boiled, to a wort heater, where it is heated to a temperature between 75 and 125 ° C, introducing the heated wort in a plug flow reactor, preferably a rotating disk contactor, followed by treatment of the wort obtained from the countercurrent reaction with steam in a distillation column.

Description

PROCESS FOR THE CONTINUOUS BLOWING OF MOSTO DESCRIPTION OF THE INVENTION This invention relates to a process for the continuous boiling of must, as well as to a process for fermenting beer from said boiled wort. When beverages are prepared from cereals, particularly when beer is fermented, must is used. A conventional preparation of the must occurs by mixing the initial materials, which comprises grain without malt (corn) and water. The solid materials are first pulverized and then mixed with the water. The resulting suspension is held for some time at a temperature of about 40 ° C in the presence of an enzymatic source, for example, malt. With this occurs gelatinization and liquefaction. In a subsequent step the enzymatic conversion of the mixture (dough) is continued after the supplementary addition of the malt and / or an external source of enzymes. It is also possible to prepare the must based on malt and water. Afterwards, the first step is omitted. The product obtained in this way consists mainly of water, insoluble components of the raw materials, as well as the soluble components thereof, such as sugars and fermentable and non-fermentable proteins. In the conventional method this mixture REF: 23218 is filtered to eliminate the insoluble components, the spent grain. The filtrate or extract is the must. For the distillation of beer, the hops are then added to the wort, which is boiled. The turbid mixture is removed, and the must is cooled to approximately 8 ° C and fermented. The objective of this wort boil operation covers a variety of goals: extraction of the bitter components of the hops, - deactivation of the enzymes and proteins, formation and agglomeration of the turbid mixture for the subsequent separation, - sterilization of the must, the elimination of volatile components that impart foul odor and evaporation of excess bubbling water. Normally the effectiveness of the boiling process is determined by three parameters. Duration, intensity (for example, evaporation) and boiling temperature. The necessary duration of boiling to complete all the desired effects is determined by the evaporation rate and the boiling temperature. The reletically slow isomerization of the hops is the step of determining the proportion or speed. At atmospheric pressure and at approximately 100 ° C, a good isimerization of the hops takes a minimum of 45 minutes. At higher temperatures and pressures the isomerization can be completed in times as short as two to three minutes. In addition to effecting the homogeneity of the boiling, the boiling vigor is of special importance for the elimination of volatile materials. The more vigorous the boiling, the better will be the elimination of ß sulfur substances that impart a bad odor. Sulfur compounds especially, such as dimethyl sulfide (DMS) have a very low taste threshold in the final beer, and can only be eliminated during boiling. The concentration of this compound will in fact increase again during the final fermentation of the must by the excretion of the yeast. The effect of boiling depuration is determined by the total evaporation during boiling, and by the geometry of the boiler of the wort to obtain a good "rotating" boil. Evaporation rates typically of 6-8% / hour are used in the brewing industry. Due to the large amounts of water that have to be evaporated to achieve the desired reduction in materials that impart a bad odor, the boiling stage is one of the most energy consuming processes in a brewing industry. Although the boiling process can be significantly accelerated at elevated temperatures, either through external heat exchangers or pressure cooking or the use of multiple effect evaporators (known as HT: boiling of High Temperature Wort)It is known that the overheating of the must has undesired effects on a number of quality aspects of the final beer, among which are color and head retention. Although this HTW process is a continuous process, with the inherent advantages thereof, this process is not acceptable due to two reasons: (a) Adverse effects on the quality of the beer, through the use of temperatures in the range of 120 at 130 ° C, which are significantly higher than what is currently used in the brewing industry, such as 100 - 108 ° C. (b) The occurrence of severe fouling by protein precipitates in the HTW retention tubes. This requires a long and intensive cleaning, which does not conform to the requirement of a continuous operation.

It could be "advantageous if the wort could be boiled continuously, such as a step that could then be incorporated into a continuous wort production process.This process could for example include the process steps described in European Patent Application No. 563,283 and 565,608, the content of which is incorporated by reference herein In order to make it possible to operate continuously, it is a requirement to have only short or negligible interruptions for cleaning and boiling under atmospheric conditions as is currently used in most The boiling operations are widely adapted in the industry The object of the present invention is to provide a continuous boiling process, which can be part of a continuous brewing, wherein the disadvantages of the prior art methods have been minimized , and whose process is able to produce a boiled must from which it can be ferme Bite a beer that has a beer quality that is comparable to the traditional batch process. The present invention relates to a process of continuous boiling of wort, said process comprising feeding the unboiled wort to a wort heater, where it is heated to a temperature between 75 and 125 ° C, introducing the heated wort into a wort. piston-type expenditure reactor, preferably a rotary disk holding reactor, followed by the treatment of the wort obtained from said reactor in countercurrent with steam in a scrubbing column. The heat sink or heat exchanger is preferably a plate or heat exchanger of shell and tube heated with steam. In this heater the incoming wort is heated from the filtration temperature (typically 75 ° C) to the boiling temperature. Due to the continuous flow, the required heating area is smaller than the 5 conventional heat exchangers. Also applicable for this purpose could "- to be an evaporator (for example of the falling film type), which could be used to heat the must as well as to produce the steam for the final purification section 0. The must is then transferred to a maintenance column, which It operates at a temperature of 75 to 125 ° C and a pressure of 1 to 2 bar, to obtain the residence time required for the various reactions to take place at temperatures close to the boiling temperature. rotary disc contactor) is equipped with a rotating shaft set with a large number of discs.The discs serve two purposes: (1) apply gentle agitation to aid coagulation and agglomeration of turbid particles and keep them in suspension, preventing this way the excessive soiling of the internal part of the column (2) obtain a controllable residence time distribution, so that all the must is subjected to the same duration at higher temperatures. As the piston-type flow-through reactor, various types of reactors can be used in whose connection it is of special importance that no unacceptable backmixing and / or pre-mixing of the components occurs. Examples thereof are tubular reactors and cascades of tank reactors more or less ideally agitated. A preferred type of reactor is the so-called rotary disk contactor, which is a known type of vertical column reactor, as described, e.g. ex. , in Kirk-Othmer, Encyclopedia of Chemical Techonology, Third edition, Vol. 9 page 702. Such a reactor generally consists of a vertical column provided with a central agitator shaft which has 10 or more discs or plates attached thereto. These discs or plates cover at least 80% of the cross section of the column. In general, this surface does not exceed 95%. By the rotation of the shaft and the discs in the column an appropriate dispersion of the solid material in the liquid occurs. The use of a contactor instead of an arrangement of holding tubes, has the advantage that due to the action of agitation, when the must passes the retention tubes at low speed (necessary to obtain an acceptable type of residence), the proteins and enzymes denatured, agglomerated, united with the resins of the hops, or the polyphenols of malt or hops, will not settle. In the past, this precipitation caused residues in the tubes at high temperatures at long times, which form an impenetrable deposit that requires a perfect cleaning action using alternating cleaning cycles with hot and cold water to "undo" the deposits from the surface of the tube. The contactor of the rotating discs prevents the formation of deposits by agitation, the absence of gates ensures a minimum of dead spots within the column. The volume of the piston-type expenditure reactor and more particularly the rotating disk contactor, is chosen to achieve a residence time of 45-75 minutes, during which time all the desired reactions will have proceeded sufficiently. In the third stage of the process the must is fed to a distillation type purification column, operating at a temperature of 75 to 125 ° C and at a pressure of 1 to 2 bar. The column is adjusted with trays on which the must is purified, preferably countercurrent with fresh saturated steam. Due to the large number of trays (at least 5 trays) and the subsequent equilibrium stages, the volatile components are removed in a very short time at a high efficiency. The residence time in the column is typically only 10 seconds to 10 minutes, preferably 0.5 to 2 minutes. Due to the high efficiency, the use of purification steam is smaller than the net evaporation during the traditional boiling of the must. The gain in energy consumption is therefore significant. The continuous operation makes possible the reutilization of the purification steam to heat the incoming must.

Optionally, the must is heated and partially evaporated in an evaporation unit, the vapors generated serving as the purification medium in the purification column. As a purification section, various types of purification and / or distillation equipment can be used, such as a column of trays or packed, as by example MR using the so-called Sulzer packing, or a column with gates. A scrubbing column will preferably have 5 or more trays or a packed height of at least 2 meters. The tray type column or plate with descent tubes ensures good mixing of the steam and the must, and has a wide operating range. Since the volume is very small, this type of column can be easily cleaned by filling and successively draining the column, either in normal flow or in reverse flow. It must be taken care of during the filtration of the pulp or dough before the must is boiled, since the particles that result from improper separation of the dough can block the sperm trays. Saturated steam is fed through a lower inlet below the lower tray or packing. Due to the highly efficient mass transfer, the steam flow can be adjusted as low as 4 to 6% by weight mass flow of the wort. A good isolated column is necessary to maintain the balance between the temperature of the must and the vapor, to prevent the vapor from condensing in the must resulting in undesired dilution of the must and the use of inefficient steam. The use of a retention column in combination with a purification column offers a number of unexpected benefits from a technological point of view of the process. As one of the most important components that impart unpleasant odor, dimethyl sulfide (DMS), is formed from a precursor or volatile, the maintenance or retention stage ensures that a maximum amount of the precursor is transformed into DMS that enters the debug section. This means that the resulting level of dimethyl sulfide will be very low, since the same DMS is removed with high efficiency in the purification section. The purified wort leaving the evaporator can now be further treated either in a continuous manner or in a traditional manner (separation of the turbid components through centrifuges or by vortex, cooling of the wort and aeration and fermentation). An additional continuous treatment of the wort leaving the boiling section means that the retention time, at high temperatures, can be shortened even a couple of minutes by separating the turbid substances in a continuous manner with a centrifuge. Traditionally, the use of a whirlpool means that the must is subjected to prolonged retention times in the interval of 20 to 100 minutes at 95 - 100 ° C, which are beneficial for the quality of the must. The cooled must may be fermented, optionally after the residence time in an intermediate storage vessel. The invention therefore relates to a process for distilling beer using the wort as described above. The process of the present invention consequently offers the following advantages: continuous operation atmospheric boiling conditions - optimal formation of turbid substances by low-cut conditions depuration of substances that impart highly efficient malodor, replacing the high evaporation ratios - efficient high energy, which makes it possible - i: high heat recovery favorable conditions of low oxidation, since there is no contact with the air a well-defined residence time in the complete set-up, which does not result in improper mixing effects or localized overheating low volume equipment enables effective cleaning and less use of cleaning agents small equipment area requirements, compared to traditional boilers, the subsequent reuse and condensation of the scrubbing steam containing the substances that impart a bad odor, prevents the emission into the atmosphere of reduced heat load on the wort, due to the shorter processing times. The invention will now be illustrated with reference to the accompanying drawing which shows an example of the process scheme according to one embodiment of the invention. The figure shows the process according to the invention, which comprises a boiling section of three elements consisting of a must entry 1, which receives the must from the filtration of the dough or the intermediate storage container of the dough This must having a temperature of 75 ° C, is heated using heat exchangers 2 and 3, which are a heat exchanger type shell and tube, spiral or a plate. The heating medium in the exchanger 2 is the steam leaving the scrubber, and the heat exchanger 3 is fed with fresh steam. In the heat exchangers the must is heated to a temperature of 100 ° C or slightly higher (1 to 3 ° C) to counteract • heat loss in the retention column 4. The must is fed to column 3 through of a pump 6 necessary to overcome the static head of the column. The holding column 3 is of the vertical rotating disk type, equipped with a rotary stirring shaft driven by a gear motor. The holding column 4 can be fed either from the upper or lower entry, the lower entry being chosen in this mode, as in this case the scrubbing column 5 is fed from the upper part, making possible a downward flow. by gravity. The residence time in the retention column can be adjusted by adding exits to selected heights in the column. The purification section 5 is fed from the bottom with saturated steam, controlled by a pressure reduction valve and a mass flow measurement coupled with a flow regulation valve. The flow velocity of the steam is adjusted as a fixed percentage of the must flow entering the debugging section, to obtain an optimal operating regime, preventing the condensation or flooding regimes on the trays. The steam that leaves the scrubber, which contains high concentrations of the cleaned components is either discharged through a chimney or can be partially condensed (by heating the incoming wort, with the exchanger 2) or it can be fully condensed by the use of the exchanger 2 in conjunction with a condenser 6, after which the condensate can be treated in the waste water processing plant. With the help of the manometer 7 and the regulating valve 8 it is possible, although not necessary, to operate the array at high pressures and temperatures, offering the opportunity to run the array at higher yields. This is of course limited only by the possible maximum flow within the operating regimes of the debug column. The wort leaving the down tube from the lower tray can be pumped 9 to the separation section 10 of the turbid material and to the subsequent processing of the wort. When the arrangement is used at high pressures the must leaving the purification section will have to be boiled to ambient conditions in a separate intermediate vessel. A level controller at the bottom of the scrubbing column separates the highest pressure in the column from atmospheric pressure in the receiving and / or boiling vessel. The invention will now be illustrated by an example, but is not limited thereto.

EXAMPLE AND COMPARATIVE EXAMPLE A must was filtered in a conventional manner, the dough having been produced by an infusion scheme, whose dough is subsequently filtered by means of a lautertun. The must entering from la.tertun had a temperature of 74 ° C. The filtrate collected from the lautertun, which has a gravity of 12.5 ° P, was sent to a heat exchanger by shell and tube, in which the must was heated, using fresh steam on the side of the shell, at the temperature of 103 ° C. ° C. The must leaving the heat exchanger was introduced to the bottom of a rotating disk contactor, with a volume of 600 liters at a flow rate of 1200 1 / h. This contactor had a vertical rotation axis provided with 40 disks. In the retention reactor (rotary disk contactor) the s-t i 1 m e t i o n i n (SMN) was satisfactorily converted to dimethyl sulfide (DMS). The must was subsequently fed to the upper section of the column with trays, equipped with 12 trays and descending tubes. The retention volume of the column was approximately 20 liters. Fresh saturated steam was fed to the lower section of the column, representing a purification ratio of 5%. The boiled wort was subsequently fed to a separator for the removal of turbid materials, and cooled. This must was further processed into beer, and bottled. The DMS level was determined at various stages of the process.

After filtration: 74 μg / 1 After the contactor 195 μg / 1 After the debugger < 10 μg / 1 * After the separator and cooling 20 μg / 1 Final beer 40 μg / 1 - *: the limit of detection is 10 μg / 1 **: well below the taste threshold As a comparison, a part of the filtrate arriving from the lautertun was boiled in a boiling boiler for conventional wort, in batches, and further processed to a beer. An analytical and organoleptic comparison showed no significant differences, except for the slightly darker color of the beer obtained by the conventional process. This can be attributed to the longer residence times at high temperature, which is known to cause wort darkening.

It is noted that in relation to this date, the best method known to the applicant to carry out the aforementioned invention, is that which is clear from the present description of the invention.

Having described the invention as above, property is claimed as contained in the following:

Claims (12)

• CLAIMS

1. A process for the continuous boiling of wort, characterized in that it comprises feeding the must without boiling it to a wort heater, where it is heated to a temperature between 80 and 110 ° C, introducing the heated wort in a piston-type expense reactor , preferably a rotating disc holding column, followed by the treatment of the wort obtained from said reactor in countercurrent with the steam in a scrubbing column.

2. A process according to claim 1, characterized in that the piston-type expense reactor has multiple outlets for controlling the residence time of the wort to an inflow flow f ij or.

3. The process according to claim 102, characterized in that the piston-type expense reactor operates at a pressure of 1 to 2 bar, and at a temperature of 75 to 125 ° C.

4. A process according to any of claims 1 to 3, characterized in that the wort heater is indirectly heated with the steam leaving the scrubbing column.

5. A process according to any of claims 1 to 4, characterized in that the pellets of the hop and / or hop extracts optionally p? They are added before or after the wort heater.

6. A process according to any of claims 1 to 6, characterized in that the scrubbing column is operated at a pressure of 1 to 2 bar, and at a temperature of 75 to 125 ° C.

7. A process according to any of claims 1 to 6, characterized in that the cleaning steam is used as the heating medium in the wort heater and / or to heat other process flows.

8. A process according to any of claims 1 to 7, characterized in that the must coming from the scrubbing column is rapidly boiled in an intermediate vessel.

9. A process according to any of claims 1 to 8, characterized in that the must is heated and partially evaporated in an evaporation unit, the vapors generated serving as the purification medium in the scrubbing column.

A process according to any of claims 1 to 9, characterized in that the boiled wort, optionally after clarification, is cooled and fermented.

11. A process for distilling beer, comprising the fermentation of the must obtained using the process according to any of claims 1 to 10.

12. The beer obtained by the process according to claim 11.