GB2537764A

GB2537764A - Tea capsule

Info

Publication number: GB2537764A
Application number: GB1610319.4A
Authority: GB
Inventors: Gort-Barten Leslie; Gort-Barten Alex
Original assignee: Individual
Current assignee: Individual
Priority date: 2013-10-31
Filing date: 2014-10-31
Publication date: 2016-10-26
Anticipated expiration: 2034-10-31
Also published as: GB2519871A; GB201321235D0; GB2537764B; GB201408970D0; GB2519871B; GB201610319D0; GB201319227D0; GB201419471D0

Abstract

A beverage capsule 1 for use in a high pressure espresso machine is arranged so that the pressure of the water and/or extracted beverage exiting the capsule is less than 2 bar. The capsule has a generally frusto-conical form with an upper surface and a lower surface comprising an annular flange 4 and a foil 3 being attached to the flange to close the capsule. The foil may be provided with a plurality of preformed perforations and the capsule may also contain a plurality of filters, a first filter 10 is attached to flange between the foil and the flange and another filter may be placed between the beverage to be extracted and the foil. The foil may be formed from paper or polypropylene. The capsule may be used for making tea, the reduction in pressure enabling the high-pressure machine to produce a pleasant, non-frothy tea.

Description

Tea Capsule he-in:on relates to a capsule for making ffea, using a high pressure'E espresso machine.

Powered espresso 'machines are Well known. The conventional espresso machine comprises a water ehanther, a heating element adapted to heat the water to around 951H. 98 C, which is then pumped under high pressure of 15 to 19 bar to a filter holder or portafilter. Lower pressure systems also exist. The filter holder typically comprises a handle portion and a holder portion provided with two or three lugs that are adapted to engage in the installed position with the machine brewhead to where the water is pumped. The holder portion is adapted to receive a filter, which is usually -a metal to Tiber of perforations through its bottom. In use, the filter is filled with coffee and the water is forced through the coffee at the high pressure tieuerated bypump to produce the espresso coffee which is collected in a cup placed under the er holder.

The classic coffee machine suffers from two pot tat drawbacks from the point of view of user convenience when preparing espresso. The first drawback is that ground coffee starts to lose its freshness and flavour after a few days and so liar the optimum espresso, the user will also need to have a coffee grinder. The other drawback is that the used espresso coffee has to be removed from the filter, which can lead to mess as the grinds are fine. Such machines can also only be used for making espresso.

ibis lead to the development Sit coffee pods, which can be used in many espresso machines. Coffee pods ese generally individually wrapped to maintain freshness and consist of a small pod made of a perforated filter paper which contains the coffee. The pod is placed in the filter holder and then disposed of after use.

Coffee pods convenient but have to fit the filter holder and be placed correctly' otherwise water leak around the edge.

This leaf to the development of high pressure capsule machines, of which the most well known are the Nespresso® system. The coffee capsules for these machines are completely sealed. The capsule machines do not use the conventional filter holder. A capsule machine typically has a two part mechanism. The first part receives the capsule and is provided with an extraction surface upon which the capsule rests. The second part is provided with a locking lever which is used to make t and second parts integral. In use, the, second part cuts the upper surface of the capsule to allow water to enter the capsule and percolate down through capsule, where it exits through the lower surface of the-capsule at multiple locations determined by the geometry of the extraction surface. An example of such a machine is disclosed in EP 0870457 or W02005/004683. Capsules in the known capsule coffe nachines are, in use, inserted into a capsule cage of the machine which holds the capsule in position.

In use, the caps ale is clamped into position in the Lachine unit r a capsule cage part holding the capsule so that it can be cut by three prongs to enable water under pressure to enter the coffee capsule, The coffee extracted in the capsule then passes through a filter plate on the other side of the capsule and as a result of this process the coffee acquires the crema which is important in an espresso. In a traditional espresso machine, the crema forms due to emulsification of the oils in the coffee, suspending them in tiny bubbles of air. Ti Nespresso type machines, a slightly different process OMITS.

in a 'espresso type machine, hot water is pumped under pressure at between 9 and 18 to the brewing chamber via the inlet in the injection assembly connected by a channel through the injection assembly to the hole at the centre of the rear of the capsule cage. On entering the brewing chamber the water moves into and around the capsule. A nonwoven plastic filter evenly disperses the water inside the capsule. The crater moves through the ground coffee and once it has reached the aluminium foil membrane of the Capsule it pushes against the membrane. This in turn presses against the pyramidal protrusions on the extraction plate. As more water enters the Capsule the pressure starts L build. The increase in pressure compacts the coffee grounds, which causes a greater resistance to the flow of water and increases the pressure in the system.

When the pressure reaches between 3 to 8 bar, aluminium foil membrane against the pyramidal protrusions. The tearing of the aluminium foil membrane causes the pressure in the system to drop slightly. However, the pressure quickly starts o build again as water continues to be pumped into the brewing chamber as the flow resisted first by the small entry points into the capsule itself and the packed coffee in capsule. The holes on the extraction plate in a "'espresso machine are asymmetric resulting in greater cavitation, i.e. the formation of tiny bubbles, in the coffee gar moting the formation of the crema.

However, although it is possible to put tea system capsule, the resultant cup is undrinkable due to the froth.

The present invention seeks to provide capsule for a g tea in a lug pressure espresso machine, in particular a machine based on the Ne.spresso system.

According to thenon there is provided a capsule adapted for ttse =n a high pressure espresso machine, having an extraction plate, which plate is provided with a plurality of shaped exit holes adapted to assist in the formation of a crema, wherein the capsule has a generally frusto-conical form with an upper surface and a lower surface, an annular flange being provided at the lower surface, a foil being attached to the flange to close the capsule, wherein the capsule is provided with a beverage to be extracted, wherein, in use, water is pumped under pressure into the capsule, the capsule being adapted so that the pressure of the water andlor extracted beverage exiting the capsule is less than 2 bar.

Preferably the pressure of the water and/or extracted tea exiting the capsule is less than 1.2 bar more preferably I bar. Preferably the relative pressure drop across the capsule after an extraction of 6 seconds or longer is at least 7 bar, more preferably 8 bar.

Preferably the foil is attached to the flange between the thi Pre ably a f pen 'd d between d the foil.

Preferably the filter is bonded to the foil Preferably, a further filter is provided between the tea and the first filter.

Preferably, the foil is provided with a plurality of preiformed perforations.

Preferably, the or each filter comprises a plurality of pores such that the pores of the further filter in the installed position are substantially not in alignment with the pores of the first filter. It is thought that this may be creating a depth filter by combining 2 or more surface filters. If the filter is less likely to block, then there is a reduced pressure drop across them, thus less cavitation.

Preferably, the capsule contents comprise dried milk. Preferably, two separate filters are attached to the front of the capsule which can be of the same porous material or a mixture of mesh and paper. Preferably the filters are formed from paper based material or polypropylene.

The invention farther provides for a method of manufacturing a tea capsule.

It has surprisingly been found that the provision of the filter results in a drop of pressure across the capsule. As a result of this, the tea passes more slowly through the filter plate of the coffee machine and does not acquire any froth as it exits the machine, The filter paper also eliminates the occasional passage of tea leaves from the capsule which would otherwise impair the tea.

Exemplary embodiments of the invention will now be described with reference to the drawings, in which: Fig.l shows a perspective view of the capsule Fig, 2 shows a side view of the capsule Fig. 3 shows an alternative embodiment with an additional filter Fig, 4a and 4b show alternative capsule forms Figure 1 shows a perspective side section of capsule I having a generally frustoconical form. The upper end of the cone frustrum has a smaller diameter than the lower end The surface; of the upper end of e cone is provided cone of weakness in the form of an annular groove 7 on the outer surface of the capsule. In use, cutting members of the capsule machine will sit just above the surface of the groove but do not pierce the capsule so that in use the water pressure bursts the weakened section and creates the path for the water to ingress the top of the capsule and into the interior of the capsule. In a manual machine that does not have cutting members, the water will simply tear or break the capsule at the zone of weakness.

The lower end 2 of the capsule is provided with a foil seal 3, whit pressed against a filter element typically comprising a plurality seal, in use, is le upstanding truncated pyramids and adapted to assist in the tearing of the foil in use so that the tea can percolate out of the capsule, A filter 10 is provided between the foil and tlic interior aaf the capsule. filletfil et i0 may be attached to the rim of the ca between the foil and the rim r g, altei hatively, tray simply it on top of the foil in the capsule but not he bonded to the capsule. The fbil may be macki of aluminium or more preferably, paper or polypropylene.

Fiume ws schematically a further embodiment in which er paper 10 is fixed between the foil and the capsule interior and d'fitrtherE filter then placed on the tea,shown,sehematicaliy as i2 in the capstile.

The interior of the capsule is provided with several strengtherring ribs to reduce the likelihood of the capsule collapsing under the pressures to which it is subjected in use. The pressure on the inside of the capsule is typically in the range of 3 to 8 bar depending on the coffee machine and the packing density of the tea in the capsule. This pressure is sufficient to cause the foil to tear against a filter plate in the coffee machine.

The capsule is provided with a flange 4 at its lower end, which flange 4 is adapted to co-operate with a retaining mecnanism o a coffee machine in use:at the capsule can be held in the correct position when in use in the coffee machine. The flange is provided with first and second annular upstanding walls spaced from one another. In use the capsule cage walls bear against at least one of the upstanding walls. It would also be possible for the first and second walls to be cut from the surface of a thicker flange. The upstanding wails are generally around 0.5-0.6nam high The capsule does not have a regular conical outer diameter over its entire length. The outer diameter of the upper part of the capsule is initially vertical and increases at a first rate until it reaches shoulder 6 when the outer diameter increases by a small amount to provide a shoulder to the rim of the capsule.

Figures 4a and 4b show alternative capsule designs. The design of Figure 4a shows a plurality of perforations or blind holes. The design of Figure 4b is a closed capsule.

Alternatively, it would be possible to have the outer diameter of the capsule increase at a second rate greater than the first rate until the rim of the capsule.

in use the capsule can be inserted in a conventional machine and the arrangement of the annular zone of weakness enables the upper surface of the capsule to be torn by water pressure from the espresso machine without the need for a cutting device. The capsule is therefore suitable for use in conventional espresso machines as well as capsule machines as the pressure of the water will force the foil against the filter plate of the espresso machine to enable the brewed tea to percolate out of the capsule. The capsule may further or alternatively be pre-piereed with 3 or more holes to assist in the pressure drop across the capsule.

In an alternative embodiment to that described above, the tea may be packed into a small bag of filter material which is inserted into the capsule, The small bag is preferably shaped to fit the interior of the capsule.

In a further embodiment, the foil is pre-perforated with a plurality of 0.3 to 1.2 mm holes or alternatively a plurality of slits.

In general it should be noted that the tea is packed less densely in the capsule than a conitsponding capsule for coffee. This allows for the expansion of the tea when it becomes wet, Around 2.2 to 2.3 g of tea is suitable for a capsule for use in an unmodified Nespresso machine. In machines adapted to work at higher water temperatures a lower weight 1.5g is possible and for ions a higher weight of up to 3.5g would he suitable.

The in in also pro ides for a method of manu tre es' tea'eapsule. he body of the capsule 1 is provided as a preformed capsule and is placed in a holder with the lower end 2 open facing upwards. The capsule is then indexed through a filling machine where the appropriate quantity of tea is placed in the capsule. The open capsule now with further indexed through the machine where in a first step, a filter paper is adhered to the Then without moving the capsule, a second filter paper is adhered to the first filter paper in the region of the satle. The filter paper pores are generally not aligned with the pores on the nd paper. The sealed capsule is then indexed out of the machine, It mild also he possible lude some dried milk iax interior of the capsule so that a white tea can he produced. Tea in the context of the application also includes us, herbal or fruit teas such as peppermint and camomile. The beverage to he extracted can include coffee to make an American°.

The filtermaterialhigh n starch, woven paper, PET (polylactic acid). Exemplary Is are polyester micron 52% open area or polypropylene 150 micron 34% open area and filter paper having a weight of 26,6.mi and a porosity greater than 1000, preferably 1300 An's.

Exemplary 'espresso machines include the Esse Citiz, latti.ssinta U, Pix stria sue (.tats: Comparative examples of the tea produced ssenza maachine using capsules manufactured by I3isio10 with single and double filter papers are provided below. In these examples, the relative pressure drop across the capsule after an extraction seconds (when the pressure has risen again to a generally steady value) is at least 7 bar, usually 8 bar. Relative pressure drop in this context is the pressure drop from the e bottom of the capsule. in other words from where the water impinges on the capsule to the point at which itithe extraction has exited the capsule.