Method and apparatus for the production of a coffee tablet

Abstract

There is provided a method for the manufacture of a coffee tablet for brewing a beverage using a beverage preparation machine, the method comprising: (i) providing a mould comprising a first portion comprising a first pre-heated compaction surface and a second portion comprising a second pre-heated compaction surface, the first and second portions being movable relative to one another between a loading configuration and a compressing configuration, wherein the first and second pre-heated compaction surfaces are pre-heated to a temperature of from 30 to 125°C; (ii) loading the mould when in the loading configuration with from 4 to 20g of roast and ground coffee; (iii) moving the first and second portions into the compressing configuration to compress the roast and ground coffee between the first pre-heated compaction surface and the second pre-heated compaction surface to form a coffee tablet; wherein step (iii) applies a force of 20 to 120kg / cm2 to the roast and ground coffee for less than 15 seconds; and wherein in the compressing configuration the mould defines at least one vent between the first pre-heated compaction surface and the second pre-heated compaction surface for discharge of gas from the mould.

Description

[0001] Method and Apparatus for the production of a coffee tablet

[0002] The present invention relates to the provision of a coffee tablet comprising roast and ground coffee which is suitable for the preparation of a coffee beverage from a beverage preparation machine. In particular, it provides a method for the manufacture of a tablet that can be subjected to a brewing process to form a coffee beverage, where the tablet has excellent properties to avoid damage before use and provides a good extraction bed. The invention further relates to an apparatus for the manufacture of the tablet.

[0003] In order to a prepare a coffee beverage it is necessary to pass water, typically hot water, through a bed of coffee grounds. The water extracts soluble coffee components to produce a desirable coffee beverage comprising the dissolved coffee solids. While a barista in a cafe may produce a compacted coffee bed by manually loading coffee grounds into a filter and tamping them, it is commonplace to provide coffee capsules and cartridges so that consumers can make equivalent beverages at home from fresh ground coffee.

[0004] There is a wide variety in the form and nature of these capsules and cartridges for home use. These range from paper filter pouches to rigid plastic or aluminium cartridges. These generally have the benefit that, once the beverage has been produced, the coffee waste material is still enclosed within the cartridge and can be readily disposed of.

[0005] However, the disposal of these capsules and cartridges presents a waste issue. Such cartridges are often difficult to recycle since they are composed of different elements with different recycling requirements. For example, a capsule might have an aluminium body, the coffee grounds and a polymer-coated foil lid, or the capsule might have a laminated polymer shell to provide oxygen barrier properties. For complete recycling these different materials would need to be separated and this can be difficult, especially where different materials are laminated together. There has therefore been a recent push to provide more environmentally-friendly packaging alternatives.

[0006] The provision of roast and ground coffee in a compacted form, such as a tablet or toroid is known and has a long history going back to coffee components used in percolator coffeemachines. In such machines the tablets provided an advantage that the right amount of coffee could be dosed for a brew cycle.

[0007] An example of a ground roast coffee tablet is shown in US9756869. These coffee tablets can avoid the need for some aspects of the product packaging, but are also prone to a number of potential disadvantages. For example, the product is prone to chipping during manufacture and handling, and this can reduce the appeal for the end consumer. The coffee tablet can also be more exposed to the atmosphere potentially leading to staling or a loss of desirable aroma components.

[0008] Another patent which sought to address these shortcomings and provide a commercially viable coffee tablet product is EP2154987. This discloses a set of compaction conditions for ensuring a suitable tablet hardness to address strength and resilience issues.

[0009] A recent coffee product on the market for consumers is CoffeeB. This is a machine and capsule system where the capsule is in the form of a compacted ball of coffee. The coffee has a biodegradable coating applied around a pre-compacted sphere of roast and ground coffee. The sphere is crushed and pierced in use to form a bed and admit water to the coffee. This means that the coffee is somewhat protected from the environment before use. After the brewing cycle the biodegradable coating acts as a container to retain the wet coffee grounds. The coffee and biodegradable coating may be composted together, reducing the issue of waste packaging.

[0010] According to their press-releases, the coating in the CoffeeB is said to use alginate, a polymer derived usually from seaweed, combined with other components to form a stable, flavourless, and heat-resistant natural oxygen barrier.

[0011] US12059008 provides an example of an alginate-based coating system and discusses how this can be formed by immersing, spraying, or other coating techniques applied to a compacted coffee pellet.

[0012] WO2023242652A discloses a method for the production of coffee tablets.US2021 / 0259271 discloses an apparatus for manufacturing tablets for hot beverage brewing.

[0013] US2023 / 0345959 discloses a method for producing tablets for extraction of a liquid food product.

[0014] EP2154987 discloses a method for manufacturing a coffee tablet designed for preparing coffee therewith, wherein an amount of coffee starting material is compacted at a particular compressive pressure so that a coffee tablet with a particular hardness is obtained.

[0015] US2024 / 0166428 discloses a capsule for preparing a beverage, in particular a hot beverage, comprising a core material in the form of a compact or a bulk material.

[0016] US2013 / 0136843 discloses a portion of product to be infused to prepare a beverage characterised in that the said portion comprises a spherical shell made of compacted ground coffee and a core made of ground coffee.

[0017] JP2010142871 discloses a mold and method for powder compression molding.

[0018] US2018 / 0290415 discloses a powder compaction mold which includes a die and upper and lower punches configured to fit into the die and is configured to compress a powder between the upper and lower punches to manufacture a powder compact.

[0019] Accordingly, it is desirable to provide an improved method for the manufacture of a coffee tablet and / or one which addresses problems with the prior art, or which at least provides a commercially useful alternative. In particular, it is an object to provide an improved industrially scalable approach to producing coffee tablets that provides a consistent high-quality product.

[0020] Accordingly, in a first aspect the present invention provides a method for the manufacture of a coffee tablet for brewing a beverage using a beverage preparation machine, the method comprising:(i) providing a mould comprising a first portion comprising a first pre-heated compaction surface and a second portion comprising a second pre-heated compaction surface, the first and second portions being movable relative to one another between a loading configuration and a compressing configuration, wherein the first and second preheated compaction surfaces are pre-heated to a temperature of from 30 to 125°C;

[0021] (ii) loading the mould when in the loading configuration with from 4 to 20g of roast and ground coffee;

[0022] (iii) moving the first and second portions into the compressing configuration to compress the roast and ground coffee between the first pre-heated compaction surface and the second pre-heated compaction surface to form a coffee tablet;

[0023] wherein step (iii) applies a force of 20 to 120kg / cm2to the roast and ground coffee for less than 15 seconds; and

[0024] wherein in the compressing configuration the mould defines at least one vent between the first pre-heated compaction surface and the second pre-heated compaction surface for discharge of gas from the mould.

[0025] The present invention will now be further described. In the following passages different aspects of the invention are defined in more detail. Each aspect so defined may be combined with any other aspect or aspects unless clearly indicated to the contrary. In particular, any feature indicated as being preferred or advantageous may be combined with any other feature or features indicated as being preferred or advantageous.

[0026] The inventors set out to provide a method for obtaining a coffee tablet to avoid the need for excess packaging. They sought to provide a tablet which would be sufficiently robust for manufacture and distribution and explored the same type of tablet formation outlined in EP2154987. However, the inventors found that this form of compaction was dependent on a large number of factors, particularly characteristics of the coffee grind, which meant that a consistent method for handling different product flavour profiles was difficult to achieve. This reduced the commercial viability of the process, since the process would need to be adapted for every different coffee flavour profile or beverage size.The inventors surprisingly discovered that the dependency of the process on the characteristics of the coffee grind could be reduced by adopting a process in which the coffee grind was subjected to a hot compaction process. Initial bench trials used pre-heated moulds but took a long time for each moulding step to complete - longer than was considered commercially viable. These initial bench trials achieved a desirable tablet and allowed some optimisation of the pressure and temperature conditions. This found that there was a balance to be struck between achieving a desirable hardness of the product and a pressure drop in the brewing system. Overly hard and compacted tablets were associated with a high back pressure, such as more than 12 Bar, which would significantly impact the beverage preparation process.

[0027] However, when the inventors went to scale up the process they found that it was not sufficiently consistent and the product was prone to cracking. That is, the tablets formed would crack during or after production. This reduces the apparent quality of the product and leaves the inside of the tablet vulnerable to staling.

[0028] It was theorised that the high temperature under the shorter moulding times required for commercial viability were leading to this cracking because of gases trapped within the tablets. The inventors surprisingly found that this issue could be addressed by ensuring that the coffee was compacted between pre-heated compaction surfaces. This meant that the trapped gases could leave the coffee during compaction along the edges of the tablet disc and the cracking was avoided. In particular, the benefits seem to be tied to upper and lower surface heating only.

[0029] The inventors found that with this method they could provide an industrially capable process which could quickly provide a number of tablets having a desired hardness and internal structure. In particular, the combination of the temperature, the force and the timing meant that the tablet had a high surface hardness for resisting damage during handling on a production line and for subsequent coating steps. This involved the formation of a protective surface "crust".Moreover, it was surprisingly found that the properties of the outer surface or "crust" resulting from the method had a smoothness that improved the adhesion and conformal nature of such coating processes. This is a benefit tied to the reduced cracking, since the presence of gases leaving the tablet can disrupt the coating process, either providing bubbles in or under the coating and, again, compromising the appearance of the tablet. The inventors have found that the claimed method (i.e. the mould, the heat, the pressure and the time) encourages gas to leave during the tablet formation (and forms a protective crust), so that the gas does not compromise the tablet. The inventors have found that the crust is particularly formed on the heated upper and lower surfaces and less so (or not at all) around the peripheral edge of the tablet.

[0030] The present invention provides a method for the manufacture of a coffee tablet for brewing a beverage using a beverage preparation machine. That is, the method makes a tablet comprising and preferably consisting of roast and ground coffee particles. These are for introduction into a beverage preparation machine, such as a brewing chamber, so that water can percolate through the coffee in the tablet to form the final beverage.

[0031] The nature and design of suitable beverage preparation machines varies. Preferably the beverage preparation machine for use with the tablet comprises means for penetrating the tablet on an upper water receiving side and means for penetrating the tablet on a lower coffee beverage dispensing side. When the tablet has a conformal insoluble coating as discussed below, preferably these penetrating means are designed to penetrate through the coating to inject into or release fluid from the tablet. The beverage machine will typically comprise a water reservoir, a pump and an inline heater. The coffee brewing chamber which receives the tablet will collect the coffee extract and direct it to a beverage receptacle.

[0032] The method of manufacturing the tablet comprises a step (i) of providing a mould comprising a first portion comprising a first pre-heated compaction surface and a second portion comprising a second pre-heated compaction surface. The first and second portions being movable relative to one another between a loading configuration and a compressing configuration. The loading configuration allows the coffee to be loaded into the mould and the compressing configuration applies a desired compression to the coffee. Preferably thefirst portion is fixed and the second portion is movable; or the first portion is movable and the second portion is fixed; or the first portion and the second portion are both movable.

[0033] In the compressing configuration the mould defines at least one vent between the first preheated compaction surface and the second pre-heated compaction surface for discharge of gas from the mould. Preferably in the compressing configuration a periphery of the first preheated compaction surface is spaced apart from a periphery of the second pre-heated compaction surface to define the at least one vent. Preferably in the compressing configuration a periphery of the first portion is spaced apart from a periphery of the second portion to define the at least one vent.

[0034] Preferably the at least one vent comprises an annular gap between the first portion and the second portion and / or comprises an annular gap between the first pre-heated compaction surface and the second pre-heated compaction surface. Providing the gap around the periphery of the tablet allows for even gas escape. It is therefore preferred that the first portion and the second portion do not touch in the compressing configuration. Preferably in the compressing configuration they are substantially evenly spaced apart from each other at the rim (i.e. typically the point of closest approach) by a distance of at least 1mm, preferably at least 2mm and more preferably from 2 to 12mm, preferably 3 to 10mm. The exact spacing will depend on the size of the tablet being formed. However, preferably the spacing is at least 10% of the height of the tablet and more preferably at least 20%. This ensures a sufficient venting region at the periphery.

[0035] Preferably the mould further comprises a tube in which the first portion and / or the second portion are movable between the loading configuration and the compressing configuration. Preferably the tube defines a side wall of a mould cavity of the mould in the compressing configuration. In practice, the provision of the tube with the sliding first and / or second portions therein provides enough of a vent for the passage of the gases out of the tablet. The first or the second portion may be integrally formed with the tube, but preferably there are three parts to the mould - the first and second portions and the tube. That is, in order for the mould parts to slide within the tube there is enough space for the gases to escape. Therefore, preferably there is no gasket or seal between the mould parts and the tube.Alternatively, a vent may be provided in the side wall of the tube to further facilitate gas escape.

[0036] Preferably the manufactured tablet has a thickness (measured in its center), corresponding to a closest separation of the opposing first and second pre-heated compaction surfaces in the compressing configuration, of from 7 to 25mm, more preferably the thickness is from 8 to 23mm, preferably 9 to 22mm, preferably 10 to 21mm, more preferably 11 to 20mm. Preferred thicknesses are 9 to 12mm, preferably 10 to 11mm and 17 to 20mm, preferably 18 to 19.

[0037] Preferably the tube has a diameter of from 3 to 5cm, preferably 3.5 to 4.5cm, preferably 3.6 to 4.3cm, preferably 3.7 to 4.1cm and most preferably about 4cm. Preferably the tube has a circular cross-section, such that the final tablet is a disc having a circular top and bottom face. Alternatively, the cross-section may be oval. Cross-sections with vertices should be avoided to avoid chippable edges in the final tablet.

[0038] Preferably, in order to provide for gas to escape from the roast and ground coffee between the first and second portions and the tube (and not allowing the coffee material to escape), there is a clearance between these mould parts and the tube of at least 0.01mm, preferably 0.02 to 1mm preferably 0.1 to 0.2mm. The first and / or second portions may have a taper on those portions extending away from the first and second first and second pre-heated compaction surfaces, such as to encourage gas to escape.

[0039] Preferably the side wall of the tube is unheated. The inventors found that the method avoided cracking in particular, when the only sources of heat were applied to the top and bottom surfaces of the compacted coffee. The unheated side wall of the tube meant that the gases which could otherwise cause cracking were better able to escape the mould. This differed from the original trials in which the whole mould had been pre-heated. In some embodiments the side wall of the tube may be actively cooled, such as with forced air or water cooling, to ensure that there is a maintained temperature gradient between the first and second compaction surfaces.Preferably the first portion comprises thermal insulation between the first pre-heated compaction surface and the tube. Preferably the second portion comprises thermal insulation between second first pre-heated compaction surface and the tube. This thermal insulation helps to ensure that the tube does not heat up during use. It is preferred that the tube wall remains below 35°C and at least 10°C, preferably at least 20°C, more preferably at least 30°C and more preferably at least 40°C, cooler than the first and second pre-heated compaction surfaces.

[0040] The first and second pre-heated compaction surfaces are pre-heated to a temperature of from 30 to 125°C. The pre-heating will generally be achieved with ohmic heating elements within the first and second portions, although other suitable heating approaches, such as circulation of a heated fluid, would also be suitable. Preferably the first and second preheated compaction surfaces are pre-heated to a temperature of from 40 to 110°C, preferably 40 to 100°C, preferably 40 to 90°C, preferably 42 to 80°C, and most preferably 45 to 75°C. Preferably the pre-heated temperature is 50 to 70°C, preferably 55 to 65°C.

[0041] Preferably the first and second pre-heated compaction surfaces are pre-heated to substantially the same temperature, such as within 5°C, more preferably within 2°C and most preferably within 1°C. It is desirable to avoid a temperature difference as this can compromise the consistency of the internal structure.

[0042] Preferably one or both of the first and second pre-heated compaction surfaces is concave and has a substantially flat central portion for forming a tablet having a rounded perimeter profile. The first and second compaction surfaces are preferably only curved at the very edges, such as the outer 5mm, preferably 1 to 4mm. When discussing the closest separation of the first and second portions above, it is the distance between these curved rims that is relevant. The provision of a rounded perimeter profile avoids providing a sharp edge which would be prone to chipping. It also gives an improved appearance and feel when handled by the consumer.

[0043] The method further comprises a step (ii) of loading the mould when in the loading configuration with from 4 to 20g of roast and ground coffee. Preferably the mould is loadedwith from 5 to 12g of roast and ground coffee, preferably 6 to 11g, preferably 7 to 10g, preferably 8g to 9g.

[0044] Although the present process is better able to form a tablet from any roast and ground coffee grind, the inventors have applied their initial discoveries when trialling EP2154987 to the hot-moulding process and consider that these factors give rise to a more reliable tablet. These factors additionally help to offset the degassing (or lack thereof) discussed below.

[0045] Preferably the roast and ground coffee loaded into the mould satisfies at least two of the following:

[0046] (a) comprises at least 50wt% Arabica, preferably at least 70wt%, more preferably at least 80wt% and preferably at least 90wt% with 100wt% in some instances. A blend of arabica and robusta coffee, such as with at least 10wt% Robusta performed best for tablet formation;

[0047] (b) has an average oil content of from 11 to 17wt%, preferably 12 to 16wt% and more preferably 13 to 15wt%;

[0048] (c) has a surface colour of 70-100 CMU, preferably 80 to 90 CMU;

[0049] (d) has a moisture content of from 2 to 4.5wt%, preferably 2.5 to 4wt%;

[0050] (e) is roasted with a peak temperature of at least 210^C, preferably a peak temperature in the range of 215 to 230^C;

[0051] (f) has a particle size distribution D50 of from 250 to 500pm, preferably 300 to 450 and most preferably 350 to 400pm.

[0052] The surface colour is a function of the roasting process and therefore determines the extend to which the coffee has been roasted. Roasting affects a number of characteristics of the coffee which determines the surface properties which are key to adhesion and hardness on compaction. These improved properties are linked to the peak roasting temperatures as discussed above. In particular, darker, longer roasts seemed to provide improved performance.

[0053] Preferably the roast and ground coffee loaded into the mould satisfies at least 3, preferably at least 4 and most preferably all of the requirements (a) to (f).The roast and ground coffee may comprise less than 20wt% of a further component, such as a soluble coffee powder. Preferably this forms less than 15wt% of the tablet, preferably less than 10wt%, and more preferably less than 5wt% of the tablet. Preferably the tablet consists of roast and ground coffee.

[0054] The method further comprises a step of (iii) moving the first and second portions into the compressing configuration to compress the roast and ground coffee between the first preheated compaction surface and the second pre-heated compaction surface to form a coffee tablet. This step applies a force of 20 to 120kg / cm2to the roast and ground coffee for less than 15 seconds. Preferably step (iii) applies a force of 40 to 110kg / cm2, preferably 50 to 100kg / cm2, preferably 45 to 95kg / cm2, preferably 50 to 90kg / cm2, preferably55 to 85kg / cm2, preferably 60 to 80kg / cm2.

[0055] Preferably step (iii) applies the force for less than 10 second, preferably 0.1 to 5 seconds, more preferably 0.5 to 5 seconds, preferably 1 to 4 seconds, more preferably 2 to 3 seconds. There is a balance to be struck between shorter times for improved commercial throughput and providing sufficient compressive force to the tablet.

[0056] The combination of these pressures, times and temperatures were found to provide an optimal balance for the final tablet. The tablets had a good surface hardness and, when brewed, did not provide an undue pressure drop over the coffee bed. Ideally the pressure drop was less than 6 Bar, preferably less than 3 bar and the process could be optimised to ensure a pressure drop of between 0.5 and 2 bar, preferably 1 to 1.5bar.

[0057] In some embodiments the roast and ground coffee is pre-heated to a temperature of from 35 to 55°C, preferably 40 to 50°C and most preferably about 45°C, immediately before loading in step (ii). Pre-heating the roast and ground coffee helps to ensure thorough penetration of the heat through the roast and ground coffee and therefore greater adhesion of the final tablet. It is preferred that the roast and ground coffee is not pre-heated as this may otherwise reduce the formation of a desirable surface crust.Preferably the first and second pre-heated compaction surfaces are each independently at least 10°C, preferably at least 20°C, more preferably at least 30°C and more preferably at least 40°C, warmer than the pre-heated coffee. This ensures that the tablet has a "crust" layer at the outer surface. This is desirable because it improves the adhesion of any coating layer to the tablet. It also means that the "core" of the tablet is less compacted and better suitable for forming a coffee bed for beverage extraction.

[0058] Preferably the coffee tablet has a surface hardness of at least 50N, preferably at least 60, preferably at least 70N. Preferably the coffee tablet has a surface hardness of 50 to 200N, more preferably 55N to 150N, more preferably 55 to 100N, more preferably 65 to 90N and more preferably 70 to 80N. The measurement process for determining the hardness is set out in the examples below.

[0059] Preferably the method further comprises (iv) forming a conformal, insoluble coating around the coffee tablet. Suitable coating techniques are well-known in the art. Preferably the conformal, insoluble coating comprises alginate. Preferably the conformal, insoluble coating has a maximum thickness of less than 1.5mm, preferably less than 1.25mm, preferably less than 1mm, such as preferably 0.1 to 1mm, 0.2 to 0.9mm and 0.3 to 0.8mm.

[0060] Preferably the roast and ground coffee loaded into the mould has been degassed after grinding for at least 1 hour. Degassing is a well-known and commonly performed step in the art of coffee grinding. When coffee is roasted there is a production of a considerable amount of gaseous species initially trapped within the beans, such as carbon dioxide. The grinding step serves to release about half of the trapped gases, with finer grinding steps releasing a greater proportion of the gas.

[0061] The remaining gas in the ground coffee will gradually diffuse out of the beans and be lost. On the one hand this degassing is desirable since packaging a non-degassed coffee leads to problems with the packaging swelling and even bursting. However, degassing takes time which reduces the commercial viability of the process and can also be associated with flavour loss, due to volatile aroma species leaving the beans.It is therefore preferable in some embodiments for the roast and ground coffee loaded into the mould to have been degassed after grinding for at least 1 hour, preferably at least 10 hours and more preferably at least 24 hours. Degassing times beyond 48 hours are less commercially desirable. The degassing process does not remove all of the gas trapped in the beans, but does reduce the risk of tablet cracking.

[0062] Surprisingly the inventors have found that the method described herein still works when the roast and ground coffee loaded into the mould has been degassed after grinding for less than 10 hours. This is surprising because the trapped gas would be expected to give rise to cracking. However, the temperature, pressure and time conditions, coupled with the specific configuration of the mould, permit the use of these shorter degassing times. This is desirable for a number of reasons. Namely, the removal of a long degassing step means: 1) that the process is more commercially viable; 2) the product has an improved aroma with fewer lost volatiles; and 3) the final beverage may have an improved crema, since this may be a function of the trapped gases.

[0063] In these embodiments with reduced degassing, preferably the degassing time between the grinding and the moulding is from 1 hour to 10 hours, preferably 1.5 hours to 8 hours, more preferably 2 to 5 hours.

[0064] The inventors found that the reduced degassing was best paired with the preferred coffee characteristics discussed above. In particular, the inventors found that a finer grind, such as 250 to 500pm (D50), preferably 350 to 450 pm and most preferably about 400pm was beneficial. It is believed that the finer grinding encourages gas release during the grinding process, such that there is less gas to be lost during degassing and before compaction.

[0065] The first portion may comprise or consist of one or more first mould parts. The second portion may comprise or consist of one or more second mould parts.

[0066] In all embodiments one or both of the first and second preheated compaction surfaces may be provided with a surface texture, embossing or relief feature, such that the process produces a tablet having an additional surface detail, i.e. a ridge, a channel or a surfacepattern. Particularly preferred is that at least one of the first and second preheated compaction surfaces has an embossed feature, such as a line or curve, such that the tablet is formed with a surface channel.

[0067] According to a further aspect there is provided an apparatus for manufacturing a coffee tablet for brewing a beverage using a beverage preparation machine, the apparatus comprising:

[0068] (i) a mould comprising a first portion comprising a first pre-heated compaction surface and a second portion comprising a second pre-heated compaction surface, the first and second portions being configured to be movable relative to one another between a loading configuration and a compressing configuration;

[0069] (ii) means for pre-heating the first and second pre-heated compaction surfaces to a temperature of from 30 to 125°C; and

[0070] (iii) means for moving the first and second portions into the compressing configuration so as to compress roast and ground coffee between the first pre-heated compaction surface and the second pre-heated compaction surface to form a coffee tablet by applying a force of 20 to 120kg / cm2to the roast and ground coffee for less than 15 seconds; and

[0071] wherein the mould further comprises at least one vent configured for discharge of gas from between the first pre-heated compaction surface and the second pre-heated compaction surface during compression of the roast and ground coffee.

[0072] Preferably the mould further comprises a tube in which the first portion and / or the second portion are movable between the loading configuration and the compressing configuration;

[0073] and optionally the tube defines a side wall of a mould cavity of the mould in the compressing configuration;

[0074] and optionally the tube has a diameter of from 3 to 5cm.

[0075] Preferably the side wall of the tube is unheated, and optionally the side wall is in thermal contact with means for actively cooling the side wall.In an alternative aspect there is provided for a method as described herein wherein, rather than roast and ground coffee, a soluble beverage composition is provided. All elements described herein for the roast and ground coffee tablets can be applied equally to the soluble beverage ingredients as discussed herein, except as otherwise noted below (or where the above discussed features of the coffee per se such as degassing or Arabica content).

[0076] In this aspect it is an object to provide an improved method for the manufacture of a soluble beverage tablet and / or one which addresses problems with the prior art, or which at least provides a commercially useful alternative. In particular, it is an object to provide an improved industrially scalable approach to producing soluble beverage tablets that provides a consistent high-quality product.

[0077] In these embodiments the water, typically hot water, does not pass through the ingredients but rather dissolves them, flushing the dissolved solids out of the beverage preparation machine and into a receptacle. As a consequence, at the end of the beverage preparation cycle all of the beverage ingredients will have been dispensed. It is therefore desirable that any conformal coating is both soluble and food-safe. Such a coating does not need to be penetrated to admit water (and hence the associated beverage preparation chamber may just have a water inlet and a beverage outlet). In use, water entering a beverage preparation chamber simply dissolves first the coating and then the ingredients, leaving behind an empty chamber. Therefore, while it is possible to provide and rely on an insoluble coating that needs to be penetrated, it is preferred for this aspect that the conformal coating is soluble. An exemplary material for such a coating comprises cellulose.

[0078] In these embodiments the hardness of the tablet represents an aspect of its suitability for use. if the tablet is not sufficiently hard, then it may fragment and break before use. If it is too hard then it may have poorer solubility. The hardness discussed herein therefore represents a suitable balance that provides a desirable beverage tablet and which is less likely to crack.Suitable soluble beverage ingredients for use in this aspect comprise one or more powdered beverage ingredients selected from soluble coffee, creamer, milk solids, foaming agents, sugar, sweeteners, flavourings, colourings, cocoa or chocolate, or a mixture of two or more thereof. Preferably the tablet is formed from a single beverage ingredient or a blend of ingredients. The ingredients may also be provided in layers or zones in the tablet. These powders may be spray-dried, freeze-dried or agglomerated as necessary (such as for milk powders) or finely ground in other instances (such as cocoa powders).

[0079] Typically, the powder form ingredients will have a particle size of less than 3mm, more preferably from 2.5mm to 10 microns, more preferably from 1 mm to 300 microns and more preferably about 500 to about 700 microns. Such particles are well known in the art.

[0080] The invention will now be described in relation to the following non-limiting figures, in which:

[0081] Figure 1 shows a compacted coffee tablet.

[0082] Figure 2 shows a compacted coffee tablet having a conformal insoluble coating layer.

[0083] Figure 3 shows a mould in a loading configuration.

[0084] Figure 4 shows a mould in a compressing configuration.

[0085] Figure 1 shows a coffee tablet 1. The coffee tablet 1 consists of roast and ground coffee 5 compacted in accordance with the method described herein. The coffee tablet 1 has an upper planar surface 10, and lower planar surface 15 and a cylindrical peripheral surface 20. There is a rounded edge 25 between each planar surface 10,15 and the peripheral surface 20.Figure 2 shows a coffee tablet 2 having an insoluble conformal coating 30 applied around all surfaces.

[0086] Figure 3 shows a mould 100 in a loading configuration. The mould 100 comprises a first portion 105 comprising a first pre-heated compaction surface 110 and a second portion 115 comprising a second pre-heated compaction surface 120. The first and second portions 105, 115 are movable relative to one another between a loading configuration and a compressing configuration (shown in Figure 4). The first and second portions 105, 115 are arranged to move snuggly within the tube 122, although as shown the first portion 105 has been removed from the tube 122 to permit loading. Alternatively loading could be achieved through an inlet in the tube 122. A similar opening of the tube 122 will be required for recovery of the final tablet. The tube 122 is unheated.

[0087] The first portion 105 is provided with an ohmic heater 125 for pre-heating the first preheated compaction surface 110. The second portion 115 is provided with an ohmic heater 130 for pre-heating the second pre-heated compaction surface 120.

[0088] The first and second pre-heated surfaces 110, 120 have curved edge portions 110a, 120a for providing the final tablet 1 with a curved edge profile.

[0089] The mould 100 is shown with an amount of roast and ground coffee 135 loaded and resting on the first pre-heated compaction surface 110.

[0090] Figure 4 shows the mould 100 in a compressing configuration. Here the first and second portions 105,115 have been driven towards each other within the tube 122. This compresses the roast and ground coffee 135. During compaction gases can escape from the roast and ground coffee 135 through the side vent portions 140. The corresponding portions of the tube 122 are unheated and may be subjected to cooling. The closest approach between the first and second portions 105, 115 is at least 2mm as measured at the closest point, i.e. at the rims.

[0091] ExamplesThe invention will now be described further in relation to the following non-limiting examples.

[0092] Measurement of surface hardness

[0093] Surface hardness is measured as the peak force before breaking using a Floyd tensile tester using a lkN loadcell. A coffee tablet is placed in such a way that the 7.5mm probe will touch it in the centre when it comes down

[0094] • Probe will come down at set pre-speed,

[0095] • As soon as the probe touches and the force analysed, exceeds 5N, the speed at which the probe comes down will be increased to lOOmm / min

[0096] • The force is analysed and the breaking force is defined as the maximum force needed to break the tablet.

[0097] Setings:

[0098] • 7.5mm diameter cylinder

[0099] • Pre-speed: lOmm / min

[0100] • Triggerforce > 5N, start measurement

[0101] • Test speed: lOOmm / min

[0102] • Max distance: 5mm

[0103] • Max. force used as unit

[0104] Exemplary breaking forces are given in the table:

[0105]

[0106]

[0107] Unless otherwise stated, all percentages herein are by weight.

[0108] The term "comprising" is intended to be inclusive and mean that there may be additional elements other than the listed elements. The term "consisting of" is intended to mean that no other elements may be present other than those listed. The term "consisting essentially of" is intended to mean that no other elements may be present other than those listed unless the other elements do not materially affect the basic and novel characteristics of the invention.

[0109] Although preferred embodiments of the invention have been described herein in detail, it will be understood by those skilled in the art that variations may be made thereto without departing from the scope of the invention or of the appended claims.

Claims

Claims:

1. A method for the manufacture of a coffee tablet for brewing a beverage using a beverage preparation machine, the method comprising:(i) providing a mould comprising a first portion comprising a first pre-heated compaction surface and a second portion comprising a second pre-heated compaction surface, the first and second portions being movable relative to one another between a loading configuration and a compressing configuration, wherein the first and second preheated compaction surfaces are pre-heated to a temperature of from 30 to 125°C;(ii) loading the mould when in the loading configuration with from 4 to 20g of roast and ground coffee;(iii) moving the first and second portions into the compressing configuration to compress the roast and ground coffee between the first pre-heated compaction surface and the second pre-heated compaction surface to form a coffee tablet;wherein step (iii) applies a force of 20 to 120kg / cm2to the roast and ground coffee for less than 15 seconds; andwherein in the compressing configuration the mould defines at least one vent between the first pre-heated compaction surface and the second pre-heated compaction surface for discharge of gas from the mould.

2. The method according to claim 1, wherein the first and second pre-heated compaction surfaces are pre-heated to a temperature of from 35 to 120°C, preferably 45 to 75°C.

3. The method according to claim 1 or claim 2, wherein in the compressing configuration a periphery of the first pre-heated compaction surface is spaced apart from a periphery of the second pre-heated compaction surface to define the at least one vent.

4. The method according to any preceding claim, wherein in the compressing configuration a periphery of the first portion is spaced apart from a periphery of the second portion to define the at least one vent.

5. The method according to any preceding claim, wherein the at least one vent comprises an annular gap between the first portion and the second portion and / or comprises an annular gap between the first pre-heated compaction surface and the second pre-heated compaction surface.

6. The method according to any preceding claim, wherein the mould further comprises a tube in which the first portion and / or the second portion are movable between the loading configuration and the compressing configuration.

7. The method according to claim 6, wherein the tube defines a side wall of a mould cavity of the mould in the compressing configuration.

8. The method according to any preceding claim, wherein the tube has a diameter of from 3 to 5cm.

9. The method according to claim 7 or claim 8, wherein the side wall of the tube is unheated.

10. The method according to any preceding claim, wherein one or both of the first and second pre-heated compaction surfaces is concave and has a substantially flat central portion for forming a tablet having a rounded perimeter profile.

11. The method according to any preceding claim, wherein the manufactured tablet has a thickness, corresponding to a closest separation of the opposing first and second preheated compaction surfaces in the compressing configuration, of from 7 to 25mm.

12. The method according to any preceding claim, wherein the mould is loaded with from 5 to 12g of roast and ground coffee.

13. The method according to any preceding claim, wherein step (iii) applies a force of 40 to 80kg / cm2.

14. The method according to any preceding claim, wherein step (iii) applies the force for 0.1 to 5 seconds.

15. The method according to any preceding claim, wherein the roast and ground coffee is pre-heated to a temperature of from 35 to 55°C immediately before loading in step (ii).

16. The method according to any preceding claim, wherein the method further comprises:(iv) forming a conformal, insoluble coating around the coffee tablet.

17. The method according to any preceding claim, wherein the conformal, insoluble coating comprises alginate and / or has a maximum thickness of less than 1.5mm, preferably 0.1 to 1mm.

18. The method according to any preceding claim, wherein the coffee tablet has a surface hardness of at least 50N, preferably 55 to 200N.

19. The method according to any preceding claim, wherein the roast and ground coffee loaded into the mould satisfies at least two of the following:(a) comprises at least 50wt% Arabica;(b) has an average oil content of from 11 to 15wt%;(c) has a surface colour of 70-100 CMU;(d) has a moisture content of from 2 to 4.5wt%;(e) is roasted with a peak temperature of at least 210^0;(f) has a particle size distribution D50 of from 250 to 500pm.

20. The method according to claim 19, wherein the roast and ground coffee loaded into the mould satisfies at least 3, preferably at least 4 and most preferably all of the requirements (a) to (f).

21. The method according to any preceding claim, wherein the roast and ground coffee loaded into the mould has been degassed after grinding for less than 10 hours.

22. The method according to any preceding claim, wherein the roast and ground coffee loaded into the mould has been degassed after grinding for at least 1 hour.

23. Apparatus for manufacturing a coffee tablet for brewing a beverage using a beverage preparation machine, the apparatus comprising:(i) a mould comprising a first portion comprising a first pre-heated compaction surface and a second portion comprising a second pre-heated compaction surface, the first and second portions being configured to be movable relative to one another between a loading configuration and a compressing configuration;(ii) means for pre-heating the first and second pre-heated compaction surfaces to a temperature of from 30 to 125°C; and(iii) means for moving the first and second portions into the compressing configuration so as to compress roast and ground coffee between the first pre-heated compaction surface and the second pre-heated compaction surface to form a coffee tablet by applying a force of 20 to 120kg / cm2to the roast and ground coffee for less than 15 seconds; andwherein the mould further comprises at least one vent configured for discharge of gas from between the first pre-heated compaction surface and the second pre-heated compaction surface during compression of the roast and ground coffee.

24. Apparatus as claimed in claim 23, wherein the mould further comprises a tube in which the first portion and / or the second portion are movable between the loading configuration and the compressing configuration;and optionally the tube defines a side wall of a mould cavity of the mould in the compressing configuration;and optionally the tube has a diameter of from 3 to 5cm.25 Apparatus as claimed in claim 23 or claim 24, wherein the side wall of the tube is unheated, and optionally the side wall is in thermal contact with means for actively cooling the side wall.

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