NL1018628C2 - Baking bread from frozen dough pieces and preparation of such dough pieces. - Google Patents

Description

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Short description: Baking bread from frozen dough pieces and preparation of such dough pieces

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FIELD AND BACKGROUND OF THE INVENTION

The invention relates to a method according to the introductory part of claim 1. Such a method is known from European patent application 0 114 451.

Traditionally, bread is prepared at night and during the night in order to complete the baking as shortly as possible before the bread is offered for sale and to obtain a product that is accepted as fresh until the end of the day. In addition to unpleasant working hours for the persons who carry out the bread-making process, this approach entails the problem that the demand for bread must be predicted prior to a day in order to bake or order the correct quantity, so that on the one hand in the course of the day there is no shortage of bread and on the other hand no residual supply of bread remains at the end of the day.

In order to also be able to bake bread during the day and to respond to variations in the demand for bread as well as the demand for different types of bread, it has long been known to freeze dough and bake the bread from the prefabricated dough. In general, the dough is frozen in the unfermented state and thawed and fermented prior to baking, because when freezing the dough in the fermented state and frozen baking problems arise with the texture of the dough, in particular unevenly distributed cavities. This is explained by the poorer cold-resistance of yeast cells in fermented dough compared to the cold-resistance of yeast cells in unfermented dough.

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However, defrosting and proofing the bread prior to baking requires a considerable amount of time, depending on the type of bread, roughly one to two hours. Baking then also takes a considerable time, so that additional demand for bread 5 can only be responded to with a large delay. This means that from about three hours before closing time it is no longer useful to respond to any large demand for bread by removing extra bread from the freezer, allowing it to thaw and rise and then bake.

Many proposals have already been made to prepare a dough which is deep-frozen in a, at least to a significant extent, fermented state and does not have to be thawed and fermented prior to baking, but in which the aforementioned negative effects on the texture of the bread at least to a large extent avoided.

These proposals focus, inter alia, on increasing the amount of active yeast after freezing, for example by adding another yeast after fermenting at low temperature and then immediately freezing (U.S. Pat. No. 3,894,555), addition of substances which stimulate the activity of yeast (U.S. Pat. No. 3,901,975). Other proposals mention, among other things, the addition of alcohol (French patent specification 2 077 037, European patent application 0 384 539) and the use of special dough compositions with a lot of protein (European patent application 0 115 108) or a lot of gluten (French patent application 2 344 229) . European patent application 0 384 539 also mentions a large number of other measures that contribute to the quality of bread baked directly from risen and frozen pieces of dough. In the initially mentioned European patent application 0 114 451 it is proposed to add a freezing point reducer to the dough, which freezing point reducer can also be an alcohol.

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SUMMARY OF THE INVENTION

It is an object of the invention to improve the structure of bread that is directly baked starting from pieces of dough that have been deep-frozen in at least a substantially fermented state.

This object is achieved according to the present invention by performing the baking of a dough piece as set out in claim 1.

The invention can in principle also be applied in combination with various measures already known for improving the structure of bread that is directly baked from dough pieces which have been deep-frozen in at least a substantially fermented state.

Particularly advantageous elaborations of the invention are described in the dependent claims.

In the following, the invention is further illustrated and elucidated on the basis of an exemplary embodiment with reference to the drawing.

BRIEF DESCRIPTION OF THE DRAWING

Figs. 1-3 are examples of room temperature-time diagrams concerning freezing,

FIG. 4 is a schematic top view of a carousel freezer with dough pieces, FIG. 5 is a schematic frontal view of applying decorative material to a dough piece, and

Figs. 6 and 7 are graphs which are examples of temperature changes over time in the baking of dough pieces according to the present invention.

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DETAILED DESCRIPTION

For preparing dough pieces using an example of a method according to the invention, for example, a conventional recipe for a bread dough with flour, yeast, lukewarm water, bread cream and salt can be used. Depending on the desired type of bread, other recipes can of course also be used.

First, the ingredients are mixed into a malleable dough. This is followed by kneading the dough, the composition of the dough changing as a result of, inter alia, absorption of water by the flour and reaction with oxygen from the air. A proofing process of, for example, around 40 minutes can then follow. The dough is then beaten and divided into balls. The dough balls then undergo a bulb gray of approximately 30 minutes. This is followed by shaping or lengthening the dough pieces. Finally, the proofing follows. The duration of the proofing is normally about 60 minutes, but when the invention is applied, the dough pieces are preferably placed in a freezer before the proofing is completed in order to freeze them. The proofing step immediately prior to freezing (including the prior cooling) is preferably at least 60% and preferably at least 70% and preferably at most 90% and preferably at most 80% complete when freezing is completed started. Said percentages can thereby express, for example, the percentage of the duration of the full speed rise of the volume increase or of the height increase in the bread tin. Depending on the type of bread being prepared, other formats of proofing may also be chosen. For example, pre-proofing can be skipped prior to the final proofing.

Freezing takes place at a temperature that is lowered after the dough has closely approached or has reached the freezing point of the dough. When the dough piece is cooled to this freezing point, a re- formation occurs

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5 relatively flat temperature gradient from the outer surface to the core of the dough. As a result, the core of the dough has already cooled to close to the freezing point of the dough when outer portions of the dough begin to freeze. Due to the small temperature difference between the core and the outside of the dough piece at the moment that the freezing of the dough starts substantially and the subsequently reduced temperature, the freezing of the dough proceeds from the outside to the inside at a relatively high speed. The explanation of the better bread structure that is obtained thanks to this method of freezing must probably be sought in a more evenly distributed moment of freezing.

It is noted that it is possible that the dough as a mixture when frozen does not show a freezing point, but a freezing range during which the temperature falls. This freezing process will, however, be short in practice and in this context is also understood by the term freezing point.

Fig. 1 shows an example of the temperature trend of the dough during freezing. The dough piece is frozen in a space in a freezer, which space is cooled by a heat exchanger.

The temperatures lowered during freezing are, according to this example, the temperature of the heat exchanger and the room temperature in the freezer.

In the diagram shown in Fig. 1, the temperature change of the dough pieces is indicated by a line D. Three phases can be distinguished therein. Firstly, the phase I of cooling the dough pieces to the freezing point, secondly, the phase II during which the dough piece freezes, and thirdly, the phase III in which the frozen dough piece cools to the storage temperature. In phase II the temperature of the dough piece remains approximately constant, unless there is a freezing process, but even then the temperature will only drop very slowly compared to the decrease in phases I and III. The temperature reached in phase III is preferably 1018628 6 lower than -29 ° C. In particular, about -30 ° C is a suitable end temperature. The storage temperature after distribution to the retail trade is preferably lower than -18 ° C.

According to the method proposed in Fig. 1, the temperature in the space (line L) during phase I preferably remains higher than -10 ° C and more preferably higher than -7 ° C. The freezing point of bread dough is at -5 ° C to -6 ° C, so that when the temperature of the bread dough approaches its freezing point, the room temperature is equal to or only slightly lower than the freezing point temperature. The temperature gradient is therefore very flat when the freezing point is reached. To achieve this effect, it is also possible to initially set the room temperature very low and to increase it during cooling of the bread dough, so that the temperature gradient in the dough becomes flatter as the temperature thereof approaches the freezing point.

Upon transition from phase I to phase II, the room temperature is preferably lowered to less than -25 ° C and preferably less than -29 ° C (in this specific example -30 ° C). Due to this low temperature during the actual freezing of the dough pieces, the freezing front runs relatively quickly from the outside to the inside through the dough piece. As a result, the dough piece freezes evenly. In addition, the rapid passing of the freezing front probably has a favorable effect on maintaining a homogeneous water distribution in the dough and on preventing unfavorable crystal formation when the water in the dough freezes.

The room temperature is kept constant after the reduction.

This offers the advantage that a maximum heat dissipation is achieved that is possible without the temperature falling below a value where the degrading effect on the yeast in the dough increases strongly.

Fig. 2 describes a diagram with alternative temperature variations, wherein the temperature is also lowered during freezing before the dough temperature has reached the freezing point. This has the effect, r4 (Π> 4 pp O .0 · 7) that the temperature gradient in the dough remains flat during the entire cooling process in phase I. In particular if the dough is frozen before it has been eaten and development continues during the cooling process This offers the advantage that the activity and thus the gas development in outer layers of the dough does not decrease much earlier than in inner layers, so that a more uniform structure is obtained and gas accumulations within relatively dense outer layers are prevented.

This effect is realized in a particularly effective manner if, as in this example, the difference between on the one hand the room temperature and the temperature of the heat exchanger and on the other hand the temperature of the dough is kept approximately constant during phase I.

FIG. 3 shows a simplified variant of the proposed method in which the temperature of the space and of the heat exchanger in phase I is gradually lowered and then kept constant until shortly before the end of phase III.

A particular advantage of the proposed method of freezing is that frozen pieces of dough lying against each other have considerably less tendency to stick to each other for up to one or two hours after they have been taken out of the cooled deep-freeze storage and can therefore still be handled for decorate and bake or possibly put back in the freezer storage.

Fig. 4 shows a carousel freezer 1 with a number of dough pieces 2 therein. The dough pieces stand on a circular plateau 3, which can rotate in a circular sense 4. It is noted that it is also possible to use a freezer for continuous processing. In it, the dough pieces move through different temperature zones, so that they can each undergo a variation of the room temperature over time, as shown for example in the diagrams discussed above.

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In such situations, the circular tray 3 is often designed as a helical path over which the dough pieces 3 move through the freezer 1.

For an even cooling and freezing of the dough pieces 5, it is advantageous if, as is the case when using the freezer 1 according to the example shown, the dough piece 2 is frozen in at least one air stream 5.6 and wherein the direction of that air stream 5, 6 relative to it varies. The air flows 5, 6 are cooled by heat exchangers 7, 8.

With the proposed carousel that rotates in a direction of rotation 4, this is realized in that the air flows 5, 6 are directed in a first section 9 of the carousel along with the direction of rotation 4 of the carousel and in another section 10 of the carousel carousel is directed against the direction of rotation 4.

In FIG. 5 shows a holder 11 containing a granular decorative material 13, such as sesame seeds, poppy seeds or wheat flakes. Above the holder 11 is a piece of dough 2 which is held upside down and which can be moved back and forth in directions indicated by a double arrow 12.

By, after freezing, exposing at least an upper part 14 of the dough piece 2 to moisture-containing air, which may for example be ambient air, moisture from the air condenses against the dough piece 2 and the dough piece 2 becomes sticky. It is also possible to moisten the dough piece for this purpose with, for example, a sprayer. By subsequently bringing the dough piece 2 into contact with the granular decorative material 13, particles of the granular decorative material 13 adhere to the dough piece and a decoration is obtained on the top side 14 of the dough piece 2. These operations are preferably carried out immediately before the bread is baked. This makes it possible to determine in a very simple and rapid manner directly before baking the bread the type of decoration that the bread must be provided with. Thus, with a very short response time .1018628 9, it is possible to respond to fluctuations in the demand for bread with different decorations. It is noted that this method of decorating can also be advantageously applied in a method in which freezing is carried out differently than that proposed in this patent application.

The application of the granular decorative material is preferably effected, as in the example shown, by pressing the dough piece 2 from above against the granular material 13. The grains are then pressed firmly against the surface 14 of the dough piece 2 to be decorated.

Because, with the proposed freezing method, the frozen dough pieces show little tendency to stick together, even after they have been outside the freezer storage for a longer period of time, it is also possible to place pieces of dough decorated with granules back into the freezer storage. Reduction of the shelf life and quality is thereby particularly limited if the application of the grains takes place without allowing the pieces of dough to thaw to a significant extent. Dough pieces that have been frozen in the manner proposed above can be exposed to room temperature outside the freezer for up to about two hours and then stored further deep-frozen without substantial loss of quality occurring.

Starting from a frozen piece of dough - in particular a piece of dough frozen according to a method as proposed - it is then intended to obtain a bread with a crispy crust and an evenly distributed, fine structure of cavities within the crust and without sticky portions. To this end, when baking a bread without completely or at least substantially defrosting the dough piece prior to baking - and possibly without any defrosting of the dough piece - the baking time is divided into at least two phases. These are a heating phase in which the oven temperature in the oven space is between 110 ° C and 160 ° C and a confection phase after the heating phase, during which confection phase the oven temperature is substantially higher than during the heating phase. It is noted that freezing at a temperature that is lowered after the dough has closely approached or has reached its freezing point makes a particularly effective contribution to a good bread structure if the baking is carried out as described above and below, but that the The proposed method of freezing also yields a better bread structure and better handling of partially thawed dough pieces if the dough piece is baked in a different, for example, per se known manner.

Table 1 shows a number of examples of the proposed method of baking bread from frozen dough pieces. Depending on the type of bread, the composition of the dough and the size of the dough piece, the temperatures and the oven can vary the duration of the different phases.

Phase Bread 400 g Bread 800 g Müsli or currants 400 g

1. Warm-up 1 *, temp: 160 ° C temp: 160 ° C temp: 160 ° C

one catch steam: on steam: on steam: on part steam valve: closed steam valve: closed steam valve: closed __ duration: 2'.30Μ__ duration: 2'.30 "__ duration: l'.OO" _ overheating: off heating: off heating: off

gang temp: to 135 ° C temp: to 135 ° C temp: to 145 ° C

part steam valve: closed steam valve: closed steam valve: closed descending duration: Γ.30 "__ duration: Γ.30" duration: 1'.30 "_

2nd temp: 135 ° C temp: 135 ° C temp: 145 ° C

steam part: half steam: half steam: half steam valve: closed steam valve: closed steam valve: closed __________ duration: 8 'duration: 10' duration: 6 '

2. I temp: 180 ° C temp: 175 ° C temp: 160 ° C

steam clothing: off steam: off steam: off steam valve: closed steam valve: closed steam valve: closed __ duration: 22 '__ duration: 18' __ duration: 27'_

II temp: 190 ° C temp: 195 ° C temp: 170 ° C

steam: off steam: off steam: off steam valve: closed steam valve: closed steam valve: closed __ duration: 8 '__ duration: 15' __ duration: 8'_

III temp: 200 ° C temp: 200 ° C

steam: off steam: off fume valve: open fume valve: open _______ ______ duration: 4 'duration: 4' _______________

Table 1 15 4018028 11

To promote deep penetrating heating, the first part of the heating phase preferably covers at least 1% of the cooking time. For this purpose it is favorable if the minimum oven temperature during the first part of the heating-up phase is at least 140 ° C and preferably at least 150 ° C.

On the other hand, the dough piece should not be over-heated during the heating-up phase. To this end, the duration of the first part of the heating-up phase preferably comprises at most 10% of the baking time. It is furthermore advantageous for this purpose if the temperature during the first part of the heating phase is at most 180 ° C and preferably at most 170 ° C. Furthermore, it is advantageous for this purpose if the lowest oven temperature during a second part of the heating-up phase is at least 15 ° C and preferably at least 20 ° C lower than the (preferably highest) oven temperature that is reached during the first part of the heating phase. heating phase is achieved, the second part of the heating phase covering at least 10% of the baking time. According to this example, the first part of the heating phase is followed by a transition phase during which the oven temperature falls to a temperature which is subsequently kept constant during the second part of the heating phase.

For achieving a uniform temperature distribution during the second part of the heating-up phase, it is advantageous if the second part of the heating-up phase covers at least 10% of the baking time. For this purpose it is furthermore advantageous if the lowest oven temperature during the second part of the heating-up phase is at least 120 ° C and preferably at least 130 ° C.

On the other hand, a too long second part of the heating phase can lead to too much drying out of the dough piece and yarn with little crust formation. Therefore, the second part of the heating-up phase preferably covers at most 30% of the baking time. For this purpose it is furthermore advantageous if the highest oven temperature during the heating phase is at most 155 ° C.

For promoting crust-like and crispiness of the crust in combination with a soft core of the bread, the confection phase preferably covers at least 60% of the baking time. On the other hand, for achieving a uniform structure of the bread with evenly and finely divided cavities, such as with bread being baked without the dough pieces being deep-frozen, it is advantageous if the confection phase covers up to 90% of the baking time.

The oven temperature during the confection phase strongly depends on the type of bread, as the examples in Table 1 illustrate. For crust formation and crispiness of the crust, the lowest oven temperature during the confection phase is preferably at least 150 ° C and preferably at least 155 ° C.

Due to the heating of the dough piece during the heating-up phase, the oven temperature during the confection phase may be slightly lower than usual. The highest oven temperature during the ready-to-wear phase is preferably at most 220 ° C and preferably at most 210 ° C. In addition, in the case of baking unfilled bread, it is advantageous to divide the confection phase into three sections with increasing temperatures.

To shorten the baking time, the dough piece can also be heated during the confection phase by the action of a microwave field in the oven space. By performing this (preferably exclusively) during the ready-to-wear phase or at least after completion of half or preferably three-quarters of the heating-up phase, the additional heating of the dough piece by the action of the micro-wave field has an effect on heating the relatively core of the dough piece containing much water, the temperature of which remains relatively far and long when baking bread from frozen dough pieces. The total baking time is then in most cases shorter than when baking bread without additional heating by a microwave field. In the first example in Table 1, a baking time of a total of approximately 35 minutes is then sufficient. The additional heating effect on the relatively large water-based core of the dough piece and, when baking, starting from deep-frozen condition, the core of the dough piece lagging behind is also achieved if the baking is carried out with a different temperature variation than previously proposed in the most general sense and additional heating. is started after a crust area of the bread in the hot oven has become relatively poor in water relative to the core. However, the risk that the additional heating results in the formation of local, relatively large cavities is then greater.

According to the described example, steam is introduced into the oven space during the warming-up phase to prevent bread from drying out during the heating-up phase and to promote effective heat transfer to the coldest parts of the dough piece. This is preferably done by introducing a "shot" of steam for a short time.

The measure applied according to the examples described in Table 1 that a fume damper is kept closed during the heating-up phase is also advantageous for preventing the dough piece from drying out. In order to subsequently promote crust formation and crispiness of the crust, the methods according to the examples shown in Table 1 open the -20 steam valve during at least one final part of the ready-to-wear phase.

Figures 6 and 7 show alternative temperature variations during baking. According to the method shown in FIG. 6, the temperature during a first initial part of the heating phase is more than 155 ° G and decreases during a subsequent part of the heating phase to approximately 135 ° C and then gradually rises to subsequently rise further during the confection phase. According to the method shown in FIG. 7, the initial temperature is 150 ° C and the oven temperature falls during the first part of the heating phase 30 to approximately 140 ° C and then rises again to more than 150 ° C. The heating of the dough piece by generating a microwave field in the oven space takes place for the first time during the second part of the heating-up phase. To compensate for the action of the microwave field, the oven temperature falls again to 140 ° C during the confection phase and baking takes about 8 minutes less than without additional heating by a microwave field.

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Claims (27)

Method for baking a bread in an oven space, starting from a frozen dough piece (2) without completely defrosting the dough piece prior to baking, characterized in that the baking takes place during a baking time divided into at least two phases, comprising: a heating phase covering at least 10% of the baking time, during which heating phase the oven temperature is between 110 ° C and 160 ° C, and a confection phase after said heating phase, during which confection phase the oven temperature is substantially higher than said oven temperature during the heating-up phase. A method according to claim 1, wherein the heating-up phase comprises at most 40% of the baking time. 3. Method as claimed in claim 1 or 2, wherein during a first part of the heating-up phase a first minimum oven temperature prevails in the oven space; wherein during a subsequent portion of the heating phase the oven temperature is substantially lower than said first minimum oven temperature and falls to a second minimum temperature, and wherein during the confection phase the oven temperature is substantially higher than said second minimum temperature. The method of claim 3, wherein the second portion of the heating-up phase covers at least 10% of the baking time. A method according to claim 3 or 4, wherein the second part of the heating-up phase comprises at most 30% of the baking time. 6. A method according to any one of the preceding claims 3-5, wherein the oven temperature during the second part of the heating phase is at least 15 ° C and preferably at least 20 ° C lower than the highest oven temperature during the first part of the heating-up phase, wherein said second part of the heating-up phase covers at least 10% of the baking time%. A method according to any one of the preceding claims, wherein the confection phase covers at least 60% of the baking time. A method according to any one of the preceding claims, wherein the confection phase comprises at most 90% of the baking time. 9. Method as claimed in any of the foregoing claims, wherein the lowest oven temperature during the heating-up phase is at least 120 ° C and preferably at least 130 ° C. A method according to any one of the preceding claims, wherein the highest oven temperature during the heating-up phase is at most 155 ° C. 11. A method according to any one of the preceding claims, wherein the lowest oven temperature during the clothing phase is at least 150 ° C and preferably at least 155 ° C. A method according to any one of the preceding claims, wherein the highest oven temperature during the clothing phase is at most 220 ° C and preferably at most 210 ° C. 13. Method as claimed in any of the foregoing claims, wherein the dough piece is co-heated during the confection phase by the action of a microwave field in the oven space. 14. A method according to claim 13, wherein the co-heating of the dough piece by means of a microwave field in the oven space is only effected after at least 50% and preferably at least 75% of the duration of the heating-up phase has elapsed. A method according to any one of the preceding claims, wherein steam is introduced into the oven space during the heating-up phase. A method according to any one of the preceding claims, wherein during the heating-up phase a fume valve of the oven is kept closed and the ice; ü O (Ci extractor valve is open during at least one last part of the confection phase. 17. Method as claimed in any of the foregoing claims, further comprising: preparing a frozen dough piece (2), comprising: mixing ingredients including flour, yeast and water into a malleable dough, kneading the dough, allowing fermentation of the dough, forming the dough into the dough piece (2) and freezing the dough piece (2) at a temperature that is lowered after the temperature of the dough piece (2) has close or has reached its freezing point. A method according to claim 17, wherein freezing takes place in a space in a freezer (1), and wherein the temperature that is lowered during freezing is the room temperature in the freezer (1). A method according to claim 17 or 18, wherein said temperature is kept constant after said reduction thereof. A method according to any one of claims 17-19, wherein said temperature is lowered at least once during freezing before the dough temperature has reached the freezing point. A method according to claim 20, wherein the difference between said temperature and the dough temperature is kept constant during cooling of the dough to the freezing point. A method according to claim 19 and optionally another of claims 17-21, wherein the room temperature in the freezer (1) for said reduction is higher than -10 ° C and preferably higher than -7 ° C. A method according to any one of claims 17-22, wherein the dough piece (2) is frozen in at least one air stream (5,6) and wherein the direction of said air stream (5,6) relative to said dough piece (2 ) varies. 24. Method according to claim 23, wherein the dough piece (2) is frozen in a carousel (3) that rotates in a direction of rotation, and wherein said airflow (5,6) in a first section of said carousel (3) with the rotational direction of the carousel (3) is also directed and is directed in another section of said carousel (3) against said rotational direction. % A method according to any one of claims 17-23, wherein the fermenting comprises a proofing step immediately prior to freezing, which proofing step 5 is at least 60% and preferably at least 70% and also at most 90% and preferably at most 80% completed when freezing is started. 26. Method as claimed in any of the claims 17-25, further comprising after freezing exposing at least an upper part of the dough piece (2) to moist air, wherein moisture from the air condenses against the dough piece (2) and subsequently applying granular decorative material (13) to at least the said upper part of the dough piece (2). 27. Method as claimed in claim 26, wherein applying the granular decorative material (13) is effected by pressing the dough piece (2) from above against said granular material. 1018628