AUTOMATIC MICROMALTING SYSTEM

Abstract: An apparatus and process for the micromalting of cereal grains particularly barley in which the grain is supported in a controlleds condition tank through the various sequentially applied malting steps to ensure repeatability. The grain is agitated during malting by being supported in cylinders on rollers in the tank.

Description: AUTOMATIC MICROMALTING SYSTEM This invention relates to a process and apparatus for the micromalting, that is, the malting in small batches of cereal grains such as barley. The production of reproducible micro malts is an essential part in assessment of barley for malting quality. This is particularly so in the assessment of new barley lines which are continually being developed. Also maltsters and brewers require a micromalting system to test barley before it is used for commercial malting and brewing to optimize production conditions for given allotments of barley grain to meet the malting quality specification. Also barley breeders and cereal chemists require the production of suitable and reproducible malts of given quality to allow the selection of superior breeding lines of barley following chemical analysis of the malts produced therein. In the past micromalting has been done only on the basis of manually moving samples of malt from one chamber to another through the various stages of malting and this has meant that reproducibility and operational efficiency is not as accurate as is desirable. It is the object of this invention therefore to provide a micromalting system which will provide reproducible results so that different barleys, tested at different times, can be accurately compared. There is provided therefore according to this invention in one form, apparatus for the micromalting of cereal grains comprising a controlled condition tank, means to support a plurality of perforated micromalting containers within the tank and means to control the conditions in the tank in accordance with the predetermined schedule to malt the grain. In a preferred form of the invention the means to support the micromalting containers may include means to agitate the container to mix any contents therein. Such a means to support the micromalting containers may comprise at least one parallel pair of rollers spaced apart to support a cylindrical container thereon and with the rollers adapted to rotate whereby to rotate the cylinder and to agitate any contents in the cylinder. The means to control the conditions in the tank may include means to circulate and condition air and water supplied into the " tank. There may also be means to supply heated air to the tank for the kilning stage of the micromalting process. Such air may be heated in the range of 10 degrees to 100 degrees depending upon the stage in the malting process. There may be further included a secondary reservoir in which water and air may be conditioned before adding at controlled temperature and condition to the micromalting tank. There may be further provided weir arrangements to control water level in the tank such that at a first level containers when supported in the tank are immersed and at a second -lower level the water level in the tank is below the level of the containers when supported in the tank. In a further form the invention may be said to reside in a process for the micromalting of cereal grains comprising the steps of supporting a plurality of samples of barley in perforated containers in a controlled condition tank, agitating the containers, and controlling the conditions in the tank according to a predetermined sequence to steep and germinate the grain whereby to malt the grain in the containers. The process may further include the steps of kilning the cereal grain after steeping and germination. It will be seen that by this invention there is provided a micromalting system which because of a controlled sequence of events which occur in a single enclosed tank reproducibility of results may be obtained. The top tank, the micromalting tank of the system may be of a rotating drum design incorporating interchangeable bed and drum assemblies enabling a single machine to be used for multiple batch sizes. Water levels may be fully adjustable for steeping, air resting, germination and the like using a controlled weir system and the kiln and air flow and heat capacities may be adjustable and fully integrated. In a preferred form, the system may use a reverse cycle refrigeration plant for cooling and heating of water and air and may also use auxiliary heating perhaps of the immersion type for heating liquid medium used to maintain the desired temperature in the bottom or reservoir tank. The liquid medium may be circulated at precise rates employing water circulating pumps to the top tank. An air circulation system may maintain a precisely controlled temperature and humidity environment for the germinating grain, the air being circulated by a fan and water circulation and adjustable water sprays being provided to humidify to the desired extent. A kilning system may be driven by a fan and heating by electrical kiln air heating elements for the purpose of drying the grain to a desired moisture content. The amount of recycling of moisture may be varied as desired. In one preferred form the containers to contain the cereal grains may be stainless steel perforated mesh canisters of various sizes from a diameter of 50 millimetres to 250 millimetres and of varying lengths depending upon the volume of grain to be malted and these may be rotated at precise speeds by rotating rollers throughout the steeping, germination and kilning processes. In a preferred embodiment the rollers may be run at speeds of 0.1 to 10 revolutions per minute. All of the functions of the micromalting system such as temperature, humidity and timing controls may be controlled by a programmable microprocessor via precision sensors and other suitable interface devices. The production of reproducible micromalts is an essential part in the assessment of new barley lines for malting quality. The basic design and control of the micromalting system of the present invention may use a digital process controller to provide fully automatic multiple program schedules on all functions including steeping, germination and kilning. These functions may all be performed in the one unit with minimum handling. A rotating drum design is a preferred embodiment of the invention and ensures malt sample uniformity and assists in maximizing repeatability. Numerous sample sizes and numbers may be possible by varying drum sizes and roller configurations, typically 80 samples of 30 grams each, or 12 samples of 1500 grams may be processed in each run. In a preferred embodiment the machine may have a capacity to accommodate 18 kilograms of grain enabling its use as a pilot malting facility. Programming versatility allows for a wide range of malting and research conditions. There may be further provided inlets for the addition of gases such as carbon dioxide or nitrogen to the micromalting tank to vary conditions. Production of special purpose malts can be achieved by controlled application of other materials such as the production of peat malt by smoke induction via a special kiln inlet port. This then generally describes the present invention but to assist with understanding the invention reference will now be made to the accompanying drawings which shows a preferred embodiment of the invention and a particular example to show the process of the present invention. The preferred embodiment of the micromalting machine of the present invention consists of two fully insulated stainless steel tanks, an upper malting tank 1 and a lower water and air preconditioning tank 2. In the upper tank 1 a pair of rollers 3 support cylindrical containers 4 in which the grain to be malted may be placed. The size of the cylindrical container 4 will depend upon the amount of grain to be malted. The roller 3 may be driven by motor 5 through drive 6 to continuously agitate the grain within the containers 4. The motor 5 may be a variable speed controllable motor to control the amount of rotation and the speed of rotation in the roller 3 and hence the amount of agitation in the containers 4. An air entry duct 7 is provided into the malting tank -1 and vents under a perforated diffusion plate 8 so that essentially an equal flow of air is achieved throughout the length of the tank 1. Humidifier sprays 9 are provided in the tank to spray water into the tank to control the humidity during the germination stage of the malting process. Water inlet 10 is provided to the tank to fill water into the tank during the wash, rinse and steeping stages of the micromalting process. Upper weir 11 provides an upper water level for the steeping stage and lower water weir 12 provides a lower water level so that some water remains in the tank during the germination stage. Drain 13 is provided to completely drain the malting tank as required. A recirculating air duct 14 is provided to recirculate air into the micromalting tank 1 and includes a heater arrangement 15 to heat air for the kilning stage and for controlling the air temperature during the various preconditioning stages. A controllable vent 16 is provided to provide for a certain amount of recycling of air depending upon the stage in the malting process. Fan 17 driven by motor 18 is provided for recycling of the air. An auxiliary inlet duct 41 controlled by valve 42 is provided to add special atmospheres such as carbon dioxide, nitrogen or smoke for particular malting tests. A water jacket 19 is provided under the micromalting tank to provide auxiliary temperature control of the conditions within the tank 1. Temperature sensor 20, humidity sensor 21 and level sensors 22 and 23 are provided in the micromalting tank 1 to monitor and control conditions in the tank. The bottom reservoir or tank 2 is provided to condition air and water before they are directed into the micromalting tank. The reservoir 2 includes a reverse cycle refrigeration coil 24 to heat or cool the contents of the reservoir as necessary and also an auxiliary electric heater 25 if necessary. Temperature sensor 26 is provided to determine the air or water temperature in the tank and humidity sensor 27 is provided to determine the humidity of air in the tank. Three level sensors 28, 29 and 30 are provided in the bottom tank. In ascending order level sensor 28 provides a safety point for water in the lower tank and with less than that level covered, no systems will operate. Level 29 provides a lower level and level 30 provides an upper level in the tank. Float valve 31 is provided as a safety back-up to maintain the water level at a desired level if other systems fail. Water spray 32 is provided to humidify air in the lower reservoir as required. Drain 33 is provided to drain water from the tank. Recirculating pump 34 is used to direct water into the micromalting tank and into the water jacket as desired and return lines 35 and 36 return water from the micromalting tank. Water inlet is at 37. Duct 38 controlled by valve 40 conducts air from the reservoir 2 into the micromalting chamber and duct 39 is provided to return air from the micromalting chamber. A suitable air circulation system (not shown) for ducts 38 and 39 is provided. This then generally describes the various components of one embodiment of a micromalting system according to the present invention. As discussed earlier the programmable controller arrangements may be provided to provide a micromalting process with reproducible results with various arrangements of steeping and germination and kilning. The controlled parameters may be entered for each cycle depending upon the tests being carried out. These may include the timing of the various stages, the temperature, the amount of agitation by the rollers and the humidity in the main micromalting tank. A typical schedule is shown in the following table 1. Cycle No. Stage Hours Minutes Temp. X Roller on % HUMIDITY 2 Rinse 0 30 16.5 100 0 3 Wβter Precond 1. 0 45 17.0 0 0 4 Steep 1 6 0 17.0 10 0 5 Air Rest 1 8 0 17.0 20 -100 6 Steep 2 6 0 17.0 10 0 7 Air Rest 2 96 0 17.0 20 100 8 Steep 3 0 0 17.0 10 0 9 Air Rest 3 0 0 17.0 20 100 10 Steep 4 0 0 17.0 10 0 1 1 Air Rest 4 0 0 17.0 20 100 12 Steep 5 0 0 17.0 10 0 13 Air Rest 5 0 0 17.0 20 100 14 Steep 6 0 0 17.0 10 0 15 Air Rest 6 0 0 17.0 20 100 16 Kiln 1 6 0 50.0 100 0 17 Kiln 2 8 0 55.0 100 0 18 Kiln 3 10 0 63.0 100 0 19 Kiln 4 k 0 70.0 100 0 20 Tank Drain The washing cycle is designed to clear the extraneous matter from the malting tank. Mains water pressure distributed via a multiple nozzle spray system. During this cycle also mains or other water enters the preconditioning tank. Refrigeration or heating is turned on only when a predetermined water level is reached and the water is conditioned to the desired temperature. The rinse cycle is effectively a steep cycle used for washing foreign matter, dust etc. from the grain. During the rinsing water rises in the malting tank to the upper steeping level and is continually circulated. During the last five minutes of the process 35 to 40 litres of water out of a total of 140 litres is dumped to reduce the accumulation of dissolved matter. A high water volume to grain volume ratio precludes the need to dump all of the steeping water. During the air rest cycle the fan is used to circulate air through the malting tank. During the water preconditioning cycle water is added to the bottom tank until the correct level is reached. The temperature of water must reach the programmed temperature and correct water level must be attained before the controller will proceed to the first steeping stage irrespective of the time taken. Water is continually recirculated in the tank in parallel with the air circulation humidificatioπ system permitting optimal heat transfer efficiency and uniform temperature. During steeping, temperature controlled water is pumped to the malting tank and continually circulated via the pump 34 and with the solenoid set in the correct manner. The water level in the malting tank being controlled by the weir arrangement to just cover the malt containers to a desired level. During the air rest process in which germination occurs the water level in the upper tank is lowered to the lower controlled level at the lower weir and humidified air is circulated across and through the grain. Further moisture control is achieved by program operation of spray nozzles 9 in the micromalting tank. Additional air may be circulated from the air in the lower chamber or from the fan 17 in the kiln chamber. It will be noted from the table that a number of steeping and resting stages may be used before the kilning stage. Kilning is commenced automatically on completion of germination. At this stage the air rest damper is closed to stop air entering from the lower reservoir and the kiln damper is automatically positioned via a controller. Kilning air enters beneath the malt bed through the diffusion plate 8 and is recycled by means of fan 17 with a desired amount of recycling. The position of the damper to determine the amount of recycling is set during each kilning cycle to a predetermined position by means of a microprocessor using feed¬ back control. The positioning of the damper controls the proportion of recirculated and fresh air during kilning. Typically the damper is 20 per cent closed for kiln stage 1, 40 per cent for kiln stage 2, 75 per cent for kiln stage 3 and 90 per cent closed for kiln stage 4. During all non-kiln cycles the damper is fully closed. Upon the completion of kilning the malt tank is fully sealed to maintain the malted samples in their malted condition for testing. It will be seen that by this invention there is provided a micromalting system to give easily reproducible results.

Claims: THE CLAIMS DEFINING THE INVENTION ARE AS FOLLOWS: 1. Apparatus for the micromalting of cereal grains comprising a controlled condition tank, means to support a plurality of perforated micromalting containers within the tank and means to control the conditions in the tank in accordance with a predetermined schedule to malt the grain. 2. Apparatus as in claim 1, wherein the means to support the micromalting containers includes means to agitate the containers to mix the grain therein. 3. Apparatus as in claim 1, wherein the means to support the micromalting containers comprises at least one parallel pair of rollers spaced apart to support a cylindrical container thereon and adapted to rotate whereby to rotate the cylinder and agitate any contents therein. 4. Apparatus as in claim 1, wherein the means to control the conditions in the tank, includes means to circulate and condition air and water in the tank. 5. Apparatus as in claim 1 , including means to supply heated air to the tank for kilning of the grain. 6. Apparatus as in claim 5, further including means to heat air in the range of 10 degrees to 100 degrees centigrade. 7. Apparatus as in claim 1 , further including a secondary reservoir in which to condition water and air before adding at a controlled temperature and condition to the tank. 8. Apparatus as in claim 1, further including weir arrangements to control water level in the tank such that at a first level containers when supported in the tank are immersed and at a lever second level, the water level in the tank is below the level of the containers when supported in the tank. 9. Apparatus for micromalting substantially as hereinbefore described with reference to the drawings. 10. A process for the micromalting of cereal grains comprising the steps of supporting a plurality of samples of barley in perforated containers in a controlled condition tank, agitating the containers and controlling the conditions in the tank according to a predetermined sequence to steep and germinate the grain whereby to malt the grain in the containers. 1 1. A process as in claim 10, including the step of kilning of the cereal grain after steeping and germination. 12. A process for the micromalting of barley substantially as hereinbefore described with reference to the example.

Inventors: CLEARY JAMES GERARD, CLEARY, JAMES, GERARD
Applicants: MICROMALTING SYSTEMS PTY LTD, MICROMALTING SYSTEMS PTY. LTD.
Application year: 1987
Main classification: C12C1
IPC codes: C12C1