GB2263071A

GB2263071A - Mixing dough

Info

Publication number: GB2263071A
Application number: GB9200139A
Authority: GB
Inventors: Michael Higgins
Original assignee: UNICREST INTERNATIONAL Ltd
Current assignee: UNICREST INTERNATIONAL Ltd
Priority date: 1992-01-06
Filing date: 1992-01-06
Publication date: 1993-07-14
Anticipated expiration: 2012-01-06
Also published as: GB2263071B; BE1003746A6; GB9200139D0

Abstract

Bread dough is prepared by delivering flour and water from a hopper 21 and tank 25 respectively into a closed batch mixing bowl 20 which has previously been loaded with dry ingredients (e.g. yeast, salt, soya flour, improver and vegetable fat). As the flour is delivered into the bowl 20 air displaced on introduction of the flour is released through an air duct 30 and delivered to the hopper 21 to speed up the delivery of flour into the mixing bowl 20. Mixing is then commenced and after about 12 to 20 seconds a vacuum is applied via a line 31 to maintain a steady vacuum level during mixing and to release pressure build up on <IMAGE>

Description

Bread Processing" The invention relates to a manufacture of bread. More particularly, the invention relates to a process for mixing and processing dough to form loaves of bread, and, more especially, to a process and apparatus for preparing bread dough.

In general, in terms of processing time, the most critical step in the manufacture of bread is generally the batch mixing of dry ingredients, flour and water.

The amount of ingredients present, the temperature of the ingredients and the mixing time are all critical elements in obtaining a uniform dough which can be readily worked.

Conventional processes for preparing bread dough involve the introduction of dry ingredients, flour and water into a batch mixer which is operated for a preset cycle time.

The cycle time is the determining factor in the supply of dough from the mixer to the other stages of the process.

This invention is directed towards providing an improved process for mixing and processing dough to form loaves of bread, more especially to an improved process for preparing bread dough with reduced cycle time over present arrangements.

According to the invention, there is provided a process for preparing bread dough comprising the steps of: introducing dry ingredients into a batch mixer, delivering flour and water into the mixer, simultaneously releasing air displaced on introduction of the flour into the mixer, commencing mixing of the ingredients in the mixer, and releasing air displaced during mixing.

In one embodiment of the invention, air released as flour is delivered into the mixer is used to assist the delivery of the flour into the mixer.

In a preferred arrangement, air released on introduction of the flour into the mixer is filtered prior to delivery to the top of a hopper from which flour is delivered into the mixer.

In one embodiment of the invention, the air displaced during mixing is released by vacuum.

In a preferred arrangement, water at a desired temperature is delivered into the dough mixer from a water blending tank having a chilled water inlet, a heated water inlet, and a normal water inlet, water from the inlets being delivered into the water tank through inlet pipe sections which extend into the water blending tank and are arranged to promote the mixing of water on introduction into the blending tank so that water is thoroughly mixed for delivery at a substantially uniform temperature into the mixer. Preferably, each inlet pipe section is provided with a plurality of spaced-apart outlet holes which are arranged to promote the thorough mixing of water from each inlet on introduction into the blending tank.

The invention also provides a process for mixing and processing dough to form loaves of bread, the method comprising the steps of: introducing dry ingredients into a batch mixer, delivering flour and water into the mixer, simultaneously releasing air displaced on introduction of the flour into the mixer, commencing mixing of the ingredients in the mixer, releasing air displaced during mixing, dividing the dough, handing up the dough, intermediate proving of the dough, moulding the dough into a desired shape, loading the shaped dough into a baking tin, final proving of the dough, cooking the dough to form loaves of bread; removing the loaves from the tins, and cooling the loaves.

In one arrangement, air released as flour is delivered into the mixer is used to assist the delivery of the flour into the mixer. Preferably, air released on introduction of the flour into the mixer is filtered prior to delivery to the top of a hopper from which flour is delivered into the mixer.

In one arrangement, the air displaced during mixing is released by vacuum.

In a preferred embodiment of the invention, water at a desired temperature is delivered into the dough mixer from a water blending tank having a chilled water inlet, a heated water inlet and a normal water inlet, water from the inlets being delivered into the water tank through inlet pipe sections which extend into the water blending tank and are arranged to promote the mixing of water on introduction into the blending tank so that water is thoroughly mixed for delivery at a substantially uniform temperature into the mixer. Preferably, each inlet pipe section is provided with a plurality of spaced-apart outlet holes which are arranged to promote the thorough mixing of water from each inlet on introduction into the blending tank.

The process preferably also includes the steps of slicing and packaging loaves of bread to produce packaged slice pans.

The invention also provides a batch mixing apparatus for use in the process of the invention, the mixing apparatus comprising: a mixing bowl, a flour hopper having an inlet for delivery of flour into the hopper and a flour outlet pipe for delivery of flour into the mixing bowl, a water tank having a water outlet pipe for delivery of water at a desired temperature into the mixing bowl, an air duct for release of air displaced on introduction of flour into the bowl, and a vacuum line for release of air during mixing.

In one embodiment of the invention, the air duct flour outlet pipes and water outlet pipes are provided with valve means which open substantially simultaneously for introduction of flour and water into the bowl mixer and for release of air displaced as the flour is introduced into the mixer.

In one arrangement, the outlet of the air duct is connected to an upper end of the flour hopper for delivery of released air into the flour hopper to speed the transfer of flour from the hopper into the mixer.

In a preferred arrangement, the water tank is a water blending tank having a chilled water inlet, a heated water inlet and a normal water inlet, inlet pipe sections extending from each inlet into the tank, the inlet pipe sections being arranged to promote the mixing of water on introduction into the blending tank so that water is thoroughly mixed in the tank for delivery into the batch mixture at a substantially uniform temperature.

Preferably, each inlet pipe section is provided with a plurality of spaced-apart outlet holes which are arranged to promote the thorough mixing of water from each inlet on introduction into the blending tank.

The invention will be more clearly understood from the following description thereof given by way of example only with reference to the accompanying drawings, in which: - Fig. 1 is a schematic view of a process for mixing and processing dough to form loaves of bread according to the invention; Fig. 2 is an elevational view of a batch mixing apparatus used in the process of the invention, Fig. 3 is a cross sectional view of a part of the apparatus of Fig. 2 in one process condition, and Fig. 4 is a cross sectional view similar to Fig. 3 in another process configuration.

The process for mixing and processing dough to form loaves of bread is schematically illustrated in Fig. 1.

Flour, water and additional conventional dry ingredients are loaded into a batch mixer 2 as will be described in more detail below. The mixer is then operated to form a dough which is divided in a divider apparatus 3. The divided dough is then handed up in step 4. The dough then goes through an intermediate proving stage 5 and a moulding stage 6 from which units of dough moulded into a desired shape are loaded into tins for final proving in a stage 7 prior to cooking in an oven 8. The hot bread loaves thus made are removed from their tins in a detinning step 9 and are subsequently passed to a cooler 10 and from there to a slicing step 11 prior to packaging 12.

Referring particularly to Figs. 2 to 4, the batch mixing apparatus for preparing dough by the process of the invention comprises a mixing bowl 20, a flour hopper 21 having an inlet 22 for delivery of flour into the hopper 21, and a flour outlet pipe 23 for delivery of flour into the mixing bowl 20. The apparatus also comprises a water tank 25 having a water outlet pipe 26 for delivery of water at a desired temperature into the mixing bowl 20.

An air duct 30 is provided for release of air displaced on introduction of flour 21 into the bowl 20. A vacuum line 31 is also provided for release of air from the bowl 20 during mixing. The flour outlet pipe 23, water outlet pipe 26 and air duct 30 are each provided with respective valves 35, 36, 37 for controlling the flow of material into and out of the bowl mixer 20.

In operation, the process for preparing bread dough according to the invention comprises introducing dry ingredients into the bowl 20 and, when the bowl is closed, delivering flour and water from the hopper 21 and tank 22 respectively, into the mixer. Simultaneously with introducing the flour and water, air displaced on introduction of the flour into the mixer is released through the air duct 30 and is delivered to the top of the hopper 21 to increase the pressure above the flour in the hopper 21 and hence speed up the delivery of flour from the hopper 21 into the mixer 20. To achieve this, when the bowl is closed the flour outlet valve 35, the water outlet valve 36 and the air duct valve 37 are opened substantially simultaneously to allow the ingredients to be introduced into the bowl while at the same time ensuring that displaced air is delivered out of the mixer.In this case displaced air is delivered to the top of the flour hopper 21 to assist in transferring flour from the hopper into the bowl mixer. When the desired amount of flour and water have been introduced into the mixer, the valves 35, 36, 37 are all closed and mixing is commenced. After about 12 to 20 seconds, the vacuum pump operates and maintains a steady vacuum level during the mixing procedure and releases the pressure build up on completion of mixing.

To achieve a good quality dough consistently, it is essential that the temperature of the water which is introduced into the mixer is substantially uniform. To achieve this, chilled water is introduced into the water blending tank 25 through a chilled water inlet line 40, normal water is delivered through a normal water inlet line 41 and heated water is delivered into the blending tank through a heated water inlet 42.Each of the water inlet lines 40, 41, 42 have pipe sections 43, 44, 45 respectively which extend into the tank 25 toward the bottom thereof and are each provided with a plurality of axially and radially spaced-apart outlet holes (not shown) which are arranged to promote the thorough mixing of water from each inlet on introduction into the blending tank 25 to ensure that a substantially uniform temperature is achieved in the blending tank so that all water delivered into the bowl mixer 20 is at substantially uniform temperature.

We have found, through extensive research development, that the process for preparing bread dough according to the invention achieves a quite dramatic and unexpected increase in cycle time. We have found that the cycle time can be reduced by up to 23 to 24% which gives an increase in productivity of up to 31 to 32%.

EXAMPLE To prepare a batch of 340Kg of dough, 192Kg of strong bakers flour, 125Kg of water at a uniform temperature of 300C are used.

23Kgs of dry ingredients comprising yeast, salt, soya flour, improver and vegetable fat are first loaded into the mixing bowl. When the bowl is closed, the valves 35, 36, 37 open simultaneously and the water and flour is delivered into the mixer in approximately 39 seconds.

The valves 35, 36, 37 are then closed and mixing/kneading is commenced. After about 12 to 20 seconds, the vacuum pump is operated to draw vacuum on the line 31.

The approximate average cycle time for the loading and mixing and kneading operation is approximately 4 minutes.

When mixing is complete, dough is discharged from the bowl mixer.

Once the valves 35, 36, 37 are closed after introduction of the air and water into the mixer, the hopper 21 and blending tank 25 are loaded with a fresh batch of flour and water respectively so that these vessels are charged when the bowl mixer is ready to receive another batch of ingredients. The cycle continues in this manner.

Many variations on the specific embodiment of the invention described will be readily apparent and accordingly the invention is not limited to the embodiments hereinbefore described which may be varied in both construction and detail.

Claims

1. A process for preparing bread dough comprising the steps of: introducing dry ingredients into a batch mixer, delivering flour and water into the mixer, simultaneously releasing air displaced on introduction of the flour into the mixer, commencing mixing of the ingredients in the mixer, and releasing air displaced during mixing.

2. A process as claimed in claim 1 wherein air released as flour is delivered into the mixer is used to assist the delivery of the flour into the mixer.

3. A process as claimed in claim 1 or 2 wherein air released on introduction of the flour into the mixer is filtered prior to delivery to the top of a hopper from which flour is delivered into the mixer.

4. A process as claimed in any preceding claim wherein the air displaced during mixing is released by vacuum.

5. A process as claimed in any preceding claim wherein water at a desired temperature is delivered into the dough mixer from a water blending tank having a chilled water inlet, a heated water inlet, and a normal water inlet, water from the inlets being delivered into the water tank through inlet pipe sections which extend into the water blending tank and are arranged to promote the mixing of water on introduction into the blending tank so that water is thoroughly mixed for delivery at a substantially uniform temperature into the mixer.

6. A process as claimed in claim 5 wherein each inlet pipe section is provided with a plurality of spaced apart outlet holes which are arranged to promote the thorough mixing of water from each inlet on introduction into the blending tank.

7. A process for preparing bread dough substantially as hereinbefore described with reference to the accompanying drawings.

8. Bread dough whenever prepared by a process as claimed in any preceding claim.

9. A process for mixing and processing dough to form loaves of bread, the process comprising the steps of: introducing dry ingredients into a batch mixer, delivering flour ånd water into the mixer, simultaneously releasing air displaced on introduction of the flour into the mixer, commencing mixing of the ingredients in the mixer, releasing air displaced during mixing, dividing the dough, handing up the dough, intermediate proving of the dough, moulding the dough into a desired shape, loading the shaped dough into a baking tin, final proving of the dough, cooking the dough to form loaves of bread; removing the loaves from the tins, and cooling the loaves.

10. A process as claimed in claim 9 wherein air released as flour is delivered into the mixer is used to assist the delivery of the flour into the mixer.

11. A process as claimed in claim 10 wherein air released on introduction of the flour into the mixer is filtered prior to delivery to the top of a hopper from which flour is delivered into the mixer.

12. A process as claimed in any of claims 9 to 11 wherein the air displaced during mixing is released by vacuum.

13. A process as claimed in any of claims 9 to 12 wherein water at a desired temperature is delivered into the dough mixer from a water blending tank having a chilled water inlet, a heated water inlet and a normal water inlet, water from the inlets being delivered into. the water tank through inlet pipe sections which extend into the water blending tank and are arranged to promote the mixing of water on introduction into the blending tank so that water is thoroughly mixed for delivery at a substantially uniform temperature into the mixer.

14. A process as claimed in claim 13 wherein each inlet pipe section is provided with a plurality of spaced apart outlet holes which are arranged to promote the thorough mixing of water from each inlet on introduction into the blending tank.

15. A process as claim ed in any of claims 9 to 14 wherein the loaves are sliced and packaged.

16. A process for mixing and processing dough substantially as hereinbefore described with reference to the accompanying drawings.

17. Loaves of bread whenever prepared by a process as claimed in any of claims 9 to 16.

18. A batch mixing apparatus for preparing dough by a process as claimed in any of claims 1 to 6, the mixing apparatus comprising: a mixing bowl, a flour hopper having an inlet for delivery of flour into the hopper and a flour outlet pipe for delivery of flour into the mixing bowl, a water tank having a water outlet pipe for delivery of water at a desired temperature into the mixing bowl, an air duct for release of air displaced on introduction of flour into the bowl, and a vacuum line for release of air during mixing.

19. Apparatus as claimed in claim 18 wherein the air duct, flour outlet pipes and water outlet pipes are provided with valve means which open substantially simultaneously for introduction of flour and water into the bowl mixer and for release of air displaced as the flour is introduced into the mixer.

20. Apparatus as claimed in claim 18 or 19 wherein the outlet of the air duct is connected to an upper end of the flour hopper for delivery of released air into the flour hopper to speed the transfer of flour from the hopper into the mixer.

21. Apparatus as claimed in any of claims 18 to 20 wherein the water tank is a water blending tank having a chilled water inlet, a heated water inlet and a normal water inlet, inlet pip sections extending from each inlet into the tank, the inlet pipe sections being arranged to promote the mixing of water on introduction into the blending tank so that water is thoroughly mixed in the tank for delivery into the batch mixture at a substantially uniform temperature.

22. Apparatus as claimed in claim 21 wherein each inlet pipe section is provided with a plurality of spaced apart outlet holes which are arranged to promote the thorough mixing of water from each inlet on introduction into the blending tank.

23. Apparatus substantially as hereinbefore described with reference to the accompanying drawings.