RELIABLE CAPSULE BEVERAGE DISPENSING SYSTEM Field of the Invention The present invention relates to a machine and a system including a seat by which a capsule can be held and where the capsule is processed so that beverage is reliably dispensed. For the purpose of the present description, a “beverage” is meant to include any human-consumable liquid substance, such as tea, coffee, hot or cold chocolate, milk, soup, baby food, etc… A “capsule” is meant to include any pre-portioned beverage ingredient, such as a flavouring ingredient, within an enclosing packaging of any material. The capsule can form an airtight packaging, e.g. a plastic, aluminium, recyclable and/or biodegradable packaging, and of any shape and structure, including soft pods or rigid cartridges containing the ingredient. The capsule material may be cellulosic, cellulose-based or a cellulosic material, such as wood pulp or wood pulp-based or paper-based or cardboard-based material. The material may be natural cellulosic material e.g. reconstituted or regenerated cellulosic material. The capsule material can be wet or dry formed. The material can be biodegradable or a biodegradable material. The material can be compostable, such as home compostable or industrially compostable. The capsule may contain an amount of ingredient for preparing a single beverage serving or a plurality of beverage servings. Background Art Certain beverage preparation machines use capsules containing ingredients to be extracted or to be dissolved and/or ingredients that are stored and dosed automatically in the machine or else are added at the time of preparation of the drink. Some beverage machines possess filling means that include a pump for liquid, usually water, which pumps the liquid from a source of water that is cold or indeed heated through heating means, e.g. a thermoblock or the like. Especially in the field of coffee preparation, machines have been widely developed in which a capsule containing beverage ingredients is inserted in a brewing device. The brewing device is tightly closed about the capsule, water is injected at the first face of the capsule, the beverage is produced in the closed volume of the capsule and a brewed beverage can be drained from a second face of the capsule and collected into a receptacle such as a cup or glass. Brewing devices have been developed to facilitate insertion of a "fresh" capsule and removal of the capsule upon use. Examples of such brewing devices are disclosed in EP 1 646 305, 1 767 129, WO 2009/043630, WO 2005/004683 and WO 2007/135136, WO 2014/056821. It is known to secure brewing chambers using a hook system, as for example disclosed in WO 2006/005755 and WO 2006/005756. The opening of capsules using a capsule opener is for example known from EP 0 512470, EP 2 068 684, WO 02/00073, WO 02/35977, US 3,260,190, US 5,649,472, CH 605 293, EP 512 468, EP 242 556, WO 2013/026845, WO 2014/076041, WO 2015/022342, WO 2015/022344, WO 2015/022345 and WO 2015/144356. The preparation of a beverage by using centrifugation is also known. Examples of centrifugation processes and corresponding devices are disclosed in WO 2008/148601, WO2008/148650, US 5,566,605, WO 2013/007776, WO 2013/007779 and WO 2013/007780. It has also been proposed to facilitate the handling of capsules by systems for extracting them, in particular by motorizing the opening and/or closure of the extraction system for inserting and/or removing a capsule. Examples of such systems are for example disclosed in EP 1 767 129, WO 2009/113035, WO 2012/025258, WO 2012/025259, WO 2012/041605, WO 2013/127476, WO 2014/096122, WO 2014/096123 and WO 2017/046294. Beverage preparation by centrifugation includes: providing a beverage (flavoring) ingredient, e.g. as powder and/or leaves, in a capsule; circulating liquid into the capsule and rotating the capsule at sufficient speed to ensure interaction of the liquid with the ingredient while creating a gradient of pressure of liquid in the capsule. Such pressure increases gradually from a centre towards a periphery of the capsule and undergo a swirling flow relative to the capsule while extracting the ingredient and forming a liquid extract flowing out at a periphery of the capsule. Examples of such systems are disclosed in WO 2008/148601, WO 2013/007776, WO 2013/007779, WO 2013/007780, WO 2017/046294, WO 2017/068134 and WO 2017/202746. WO 2021/122502 discloses a centrifugal beverage machine with a rotatable valve arrangement for controlling a flow of water towards a centrifugal beverage mixing chamber. The capsule can be secured between facing capsule handlers that are secured by a fastening device, e.g. as disclosed in WO 2012/007293, WO 2013/007776, WO 2013/007779, WO 2013/007780 and WO 2014/102048. WO 2008/148646 and WO 2008/148650 describe a beverage preparation device wherein a flow restriction is created downstream of the receptacle, in particular a capsule, for example, by a valve which opens or enlarges under the pressure created by the centrifuged liquid leaving the receptacle. The higher the rotational speed, the more the valve opens or enlarges. The valve can be formed by a mobile restriction part of the device which is elastically urged against a rim portion of the capsule. In WO 2017/068134 the centrifugal brewing chamber is fitted with an outlet valve that can be controlled by an inertia body of the machine rotating with the centrifugal brewing chamber. The valve leads into a collector forming a crema chamber in which the beverage upon undergoing a pressure drop at the valve is refined for dispensing into a user-recipient, e.g. a cup or a mug. Such collection chamber is typically arranged around the centrifugal brewing chamber, as for example disclosed in WO 2020/201469. Capsule centrifugation to prepare coffee has been commercialized under the brand VERTUO® by NESPRESSO®. It has been proposed to prepare beverages by centrifugation along a horizontal axis. WO 2015/173123 and WO 2015/173124 disclose a centrifugal brewing chamber formed between two enclosing parts that are relatively translatable between an open position and a closed position. The enclosing parts cooperate with a pair of jaws that are movable between a capsule holding position to hold a capsule between the enclosing parts in the open position and a capsule release position to release the capsule. The jaws are actuated by a first actuator and a second actuator that are activated by the enclosing parts during their the relative translation. The jaws guide a capsule into a position between the enclosing parts in the open position and immobilize the capsule thereinbetween. Then, when the enclosing parts are translated together to enclose the capsule, the jaws release the capsule so that the brewing chamber is formed about the capsule. The enclosing parts are rotated about a horizontal axis to centrifuge the capsule for preparing the beverage with the ingredient in the capsule. At the end of beverage preparation, centrifugation stops and the enclosing parts are relatively translated to the open position whereby the used capsule is allowed to drop from the enclosing parts. Then the jaws are brought back into their capsule holding position. Further centrifugal beverage machines are disclosed in EP2021201687.7, EP2021202356.8, EP2021216919.7, EP2021216927.0, EP2021216930.4, EP 21216965.0, EP2021216970.0 and EP2021216976.7. Summary of the Invention It is therefore an object of the present invention to alleviate at least some of the abovementioned problem, in particular to provide a system for processing and reliable dispensing beverage from a capsule. It is a preferred object of the present invention to provide a system for processing and reliable dispensing beverage from a capsule made of a soft and sticking and/or tearable material, such as a material that becomes soft and sticking and/or tearable by exposure to the extraction liquid e.g. to water. For example, the capsule material is cellulosic, cellulose-based or cellulosic material, such as wood pulp or wood pulp-based or paper- based or cardboard-based material. The material may be natural cellulosic material e.g. reconstituted or regenerated cellulosic material. The capsule material can be wet or dry formed. The material can be biodegradable or a biodegradable material. The material can be compostable, such as home compostable or industrially compostable. The invention thus relates to a machine for preparing a beverage from an ingredient contained in a capsule by supplying an extraction liquid, e.g. water, into such capsule. The extraction liquid may be supplied from a liquid source via a liquid driver and thermal conditioner. The machine includes: a machine outlet configured to dispense beverage externally towards an area for placing a user-recipient, such as a cup or a mug; and a seat for holding such capsule during beverage preparation. The seat has: a seat liquid inlet configured for delivering the extraction liquid to such capsule, such as a liquid inlet associated with one or more capsule inlet openers; and at least one seat outlet at the capsule during beverage preparation, the seat outlet(s) being configured to guide beverage from the capsule, the seat outlet being associated with a capsule outlet opener, e.g. an opener delimiting a peripheral beverage passage and/or an inside beverage passage. For instance, the machine is a coffee, tea, chocolate, cacao, milk or soup preparation machine. For example, the machine is arranged for preparing, a beverage by passing hot or cold water or another liquid through the capsule containing the ingredient and held by the seat. Typically, the ingredient is or contains a flavouring ingredient of the beverage to be prepared, such as ground coffee or tea or chocolate or cacao or milk powder. Such beverage preparation typically includes the mixing of a plurality of beverage ingredients, e.g. water and milk powder, and/or the infusion of a beverage ingredient, such as an infusion of ground coffee or tea with water. One or more of such ingredients may be supplied in loose and/or agglomerate powder form and/or in liquid form, in particular in a concentrate form. A carrier or diluent liquid, e.g. water, may be mixed with such ingredient to form the beverage. Typically, a predetermined amount of beverage is formed and dispensed on user-request, which corresponds to a portion (e.g. a serving). The volume of such a serving may be in the range of 15 to 1000 ml such as 25 to 600 ml for instance 40 to 250 ml, e.g. the volume for filling a cup or mug, depending on the type of beverage. Formed and dispensed beverages may be selected from ristrettos, espressos, lungos, cappuccinos, café latte, americano coffees, teas, etc... For example, a coffee machine may be configured for dispensing espressos, e.g. an adjustable volume of 20 to 60 ml per serving, and/or for dispensing lungos, e.g. a volume in the range of 70 to 200 ml per serving, and/or for dispensing americanos, e.g. a volume in the range of 150 to 750 ml. The seat may be connected to a motor to drive during beverage preparation the seat in rotation to centrifuge the capsule so as to mix the ingredient and the extraction liquid to form the beverage. The centrifugation process for preparing a beverage is known for example from EP 2000 062, EP 2155 020, EP 2 152 128, WO 2008/148646, WO 2009/106175, WO 2009/106589, WO 2010/026045, WO 2010/026053, WO 2010/066736, WO 2008/148650, WO 2008/148834, WO 2010/066705, WO 2010/063644, WO 2011/023711, WO 2014/096122 or WO 2014/096123. The machine includes a beverage passage extending from the seat outlet(s) up to the machine outlet, said at least one seat outlet. The beverage passage and the machine outlet form an outflow path having a direction of beverage flow extending therealong and a flow cross- section transverse to the direction of flow along the outflow path. The flow cross-section along the direction of flow has a smallest cross-section, e.g. at such at least one seat outlet, with a surface area of at least 4.5 mm2, such as at least 5 mm2, for example at least 7 mm2, e.g. at least 9 mm2. Typically, this surface area is of less than 20 mm2, such as less than 15 mm2, for example less than 12 mm2, e.g less than 11 mm2. The capsule may have or be made of a soft and/or tearable material, such as a material that becomes soft and sicking and/or tearable by exposure to said extraction liquid e.g. to water. Thus, by properly adjusting the smallest flow cross- section, clogging with small ingredient particles from the capsule, e.g. coffee fines, may be prevented. The release of such particles may typically result from using the soft and/or tearable capsule material, the dimensions of which upon opening in a moist environment can vary significantly. At the same time, the flow cross-section can be kept sufficiently small to retain the capsule material at the seat whereby clogging by capsule material is avoided. Prior art smallest flow cross-sections typically have a surface area of 3 mm2 or even less. Such cross-sections may get clogged by coffee fines. This requires proper confinement of coffee fines within the capsule and thus reliably filtering capsule outlet(s) that neither unduly hinder the flow nor insufficiently filtering the flow. However, using capsule materials that are significantly softened by the passage of extraction liquid entail the risk of unreliably sized capsule outlets and thus some outflow of coffee fines. This in turn requires a system that is able to cope with the fines downstream the capsule. Further possible implementation details of the capsule holding seat are disclosed in WO 2023/3118244, WO 2023/3118245, WO 2023/3118246, WO 2023/3118247, WO 2023/3118248 and WO 2023/3118249. The machine may include a (stationary) frame and/or an outside housing in which and/or to which the machine’s components are mounted or fixed or assembled. Exemplary beverage preparation architectures are for example disclosed in WO 2009/074550 and WO 2009/130099. Typically, the machine includes one or more of the following components: a) a fluid system in fluid communication with the capsule during beverage preparation; b) an in-line heater and/or cooler for thermally conditioning a flow of liquid circulated into the capsule or a batch heater and/or cooler for circulating thermally conditioned liquid from the batch heater and/or cooler to the capsule; c) a pump for pumping liquid to the capsule, in particular a low pressure pump e.g. within the range of 1 to 5 bar, such as 1.5 to 3 bar; d) a motor for driving the capsule in rotation during beverage preparation; e) an electric control unit, in particular comprising a printed circuit board (PCB), for receiving instructions from a user via an input user-interface and for controlling the heater and/or cooler, pump and motor(s); and f) one or more sensors for sensing at least one characteristic selected from characteristics of fluid system, the heater and/or cooler, the pump, a liquid tank, an ingredient collector, a flow of the liquid (e.g. by a flowmeter), a pressure of the liquid and a temperature of the liquid, and for communicating such characteristic(s) to the control unit. The machine may include a control unit for controlling at least one electric machine components, such as a liquid driver, thermal conditioner, user- interface, actuator of the extraction seat, actuator of a seat member (when the seat member is movable relative to the seat) etc… Examples of control units and user- interfaces are disclosed in WO 2008/138710, WO 2009/043851, WO 2009/043865, WO 2009/092745, WO 2010/003932, WO 2010/037806, WO 2010/046442, WO 2011/020779, WO 2011/026853, WO 2011/054889, WO 2011/067156, WO 2011/067157, WO 2011/067181, WO 2011/067188, WO 2011/067191, WO 2011/067227, WO 2011/067232, WO 2011/144719, WO 2012/032019, WO 2012/072761, WO 2012/072764, WO 2012/072767 and WO 2012/093107. The seat for holding the capsule can be fluidically connected to a machine outlet and to a liquid supply, e.g. water supply, such as a liquid tank or an external liquid delivery line. The liquid supply and the seat may be fluidically connected together via a liquid driver, e.g. a pump, and/or a thermal conditioner for liquid, e.g. a heater and/or cooler, such as a thermoblock or thick film heater. Examples of pumps in beverage machines are disclosed in WO 2006/005425, WO 2009/024500, WO 2009/150030, WO 2010/108700 and WO 2011/107574. A suitable heater may be a boiler, a thermoblock or an on demand heater (ODH) e.g. a thick film heater, for instance an ODH disclosed in EP 1 253 844, EP 1 380 243 and EP 1 809 151. Other heaters are disclosed in WO 2009/043851, WO 2009/043865, WO 2009/092746 and WO 2011/157675 and WO 2012/007260. The heater may be associated with the seat, e.g. as disclosed in WO 2023/118245. The machine may include a plurality of the above seat outlets, such as a number of seat outlets in the range of 5 to 40 for example 10 to 35 e.g. 20 to 30. For example, the plurality of seat outlets are connected to the same machine outlet e.g. via the same beverage passage. The or each capsule outlet opener can have a capsule opening blade configured to form a corresponding outlet slit in the capsule, e.g. a blade extending in a straight plan to form a straight outlet slit in the capsule. For example, the capsule blade forms a cutting edge that has at least one cutting ramp e.g. a pair of cutting ramps in a symmetrical or asymmetrical V-configuration. The cutting edge may have a height in the cutting direction of at least 1 mm, such as at least 1.5 mm. The or each capsule outlet opener may be sized and positioned in the seat to form a corresponding outlet slit in the capsule, the formed slit having: a length of at least 1.5 mm, such as at least 1.75 mm, for example at least 2 mm, e.g. at least 2.25 mm; and a width of at least 0.2 mm, such as at least 0.3 mm, for example at least 0.4 mm, e.g. at least 0.5 mm. The or each capsule outlet opener can be sized and positioned in the seat to form a corresponding outlet opening in a membrane of the capsule. The or each capsule outlet opener may project out of the associated seat outlet towards and into the capsule so as to form a corresponding outlet opening in such capsule when held by the seat during beverage preparation. The or each capsule outlet opener, such as a or the abovementioned opening blade, can have a foot in the corresponding seat outlet, the foot being located behind a capsule opening extremity that is configured to enter the capsule, the opening extremity having a maximum cross-section that is larger than a maximum cross-section of the corresponding seat outlet. For example, the or each capsule outlet opener is substantially spear-shaped or halberd-shaped. The or each capsule outlet opener may project at a distance from the seat outlet(s) so as to form a corresponding outlet opening in such capsule when held by the seat during beverage preparation. For example, such opener is a frusto conical or frusto pyramidal piercer, the piercer being optionally provided with a concave base. Typically, a concavity or concavities in such base may be used to guide beverage out of the capsule. The seat around the above at least one seat outlet can be configured to hold counter-outflow a capsule wall, such as a capsule membrane, of the capsule around the capsule outlet opener during beverage preparation, such seat outlet having a surface area at the capsule wall in the range of 9 to 12 mm2 e.g. 10 to 11 mm2. The seat liquid inlet and the above at least one seat outlet can be positioned in the seat to face a same face, e.g. a same membrane, of the capsule when held by the seat. For example, the seat liquid inlet is associated with the above one or more capsule inlet openers. The seat liquid inlet may be associated with the capsule inlet opener(s), such as with 2 to 6 e.g. 3 to 4 inlet openers e.g. surrounding the seat liquid inlet. The capsule inlet opener(s) may be sized and positioned in the seat to form a corresponding inlet opening in a or the above membrane of the capsule. The seat typically includes a first capsule enclosure part and a second capsule enclosure part movable relative to each other between a proximate position for enclosing in an enclosure formed by the parts the capsule to process it so as to prepare a beverage therefrom and a distant position for inserting the capsule into the enclosure and removing the capsule from the enclosure e.g. towards a used capsule collector. The first and second capsule enclosure parts may be movable relative to each other by an actuator, such as a motor or a handle. One enclosure part of the first and second enclosure parts can bear the above seat outlet(s) associated with the capsule outlet opener and optionally the seat liquid inlet e.g. associated with the above capsule inlet opener(s). The machine typically has a passage for evacuating the capsule upon preparing a beverage from such capsule in the machine. Such evacuation passage may lead to a capsule collector associated with the machine. The machine may include an actuator, such as a motor or a handle, to move relatively the first and second enclosure parts between the proximate and the distant positions. The enclosure parts may be moved relatively to each other via a transmission, such as a gear transmission and/or an articulated lever transmission typically including pivotally connected levers. Examples of such actuators and transmissions are disclosed in WO 2005/004683, EP1767129, WO 2007/135136, WO 2009/043630, WO 2011/144719, WO 2012/093108 and WO 2020/064984. The first capsule enclosure part and the second capsule enclosure part in their proximate position may be connected to a motor to drive the enclosure parts in rotation so as to centrifuge in the enclosure the capsule to mix the ingredient and the extraction liquid to form the beverage. The centrifugation process for preparing a beverage is known for example from EP 2000 062, EP 2155 020, EP 2 152 128, WO 2008/148646, WO 2009/106175, WO 2009/106589, WO 2010/026045, WO 2010/026053, WO 2010/066736, WO 2008/148650, WO 2008/148834, WO 2010/066705, WO 2010/063644, WO 2011/023711, WO 2014/096122 or WO 2014/096123. The machine may have a capsule removal arrangement for assisting removal of such capsule when the first and second parts are brought from the proximate to the distant position, the first capsule enclosure part having a first cooperating face configured to extend over a first capsule face and/or the second capsule enclosure part having a second cooperating face configured to extend over a second capsule face. For example, the capsule has a lateral face extending between the first and second capsule faces, e.g. a cylindrical and/or conical and/or spherical lateral face. The capsule removal arrangement may include a first pusher with a first pusher face for contacting and pushing the first capsule face away from the first cooperating face and/or a second pusher with a second pusher face for pushing the second capsule face away from the second cooperating face. For example, the first cooperating face extends around the first pusher face and/or the second cooperating face extends around the second pusher face. At least one face of the first and second cooperating faces can be fixed to one or more of at least one capsule inlet opener and at least one of capsule outlet opener, the corresponding pusher face being configured to move or be moved beyond the opener(s) while pushing the capsule face away from such one face. In the proximate position of the first and second capsule enclosure parts, the first pusher face and the first cooperating face may have a surface area ratio of at least 0.1, for instance at least 0.33, such as at least 0.5, optionally at least 0.5, e.g. at least 0.66 or at least 0.75; and/or at most 10, for instance at most 5, such as at most 3, optionally at most 2, e.g. at most 1.5 or at most 1.33. In the proximate position of the first and second capsule enclosure parts, the second pusher face and the second cooperating face can have a surface area ratio of at least 0.05, such as at least 0.065, for example at least 0.08; and/or at most 0.2, such as at most 0.15, e.g. at most 0.10. By increasing or better balancing the surface area of such pusher face vis-à-vis the cooperating face from which the corresponding capsule face is separated by being pushed by the pusher face, tensions on the capsule face are better spread and the capsule face is less like to be torn (especially when the capsule is made of soft and/or tearable materials, and generally reducing the risk of improper or failed removal of the capsule from the corresponding cooperating face is less likely to occur. Hence, the machine with such a capsule pusher, the capsules, even those made of soft and/or tearable materials, may be removed reliably from the enclosure of the seat after extraction liquid, e.g. water, has been supplied into such capsule for preparing the beverage. The invention also relates to a system comprising a machine as described above and the abovementioned capsule which is held by the seat. Another aspect of the invention concerns a use of a capsule for a machine as described above. The capsule in such system or of such use may include or be made of a soft and/or tearable material, such as a material that becomes soft and/or tearable by exposure to said extraction liquid e.g. to water. Typically, the capsule has a body containing an ingredient and a peripherally projecting flange, e.g. a body in the shape of a cup with a bottom part, e.g. forming the second capsule face, and a lid, e.g. forming the first capsule face, covering the mouth of the cup and extending beyond the mouth to form the peripherally projecting flange. The capsule may have a body that is symmetric or asymmetric, conical or frusto-conical or cylindrical or spherical or hemispherical or frusto-spherical, containing the ingredient, e.g. ground coffee, tea or cacao or another beverage ingredient. The capsule may be of the type described above under the header “field of the invention”. The capsule may be a capsule that has a container-body, e.g. a generally cup- shaped or hemispherical or hemi-ellipsoidal body, having a flange to which a cover lid (or membrane) is attached, in particular sealed. Typically, the capsule contains a beverage ingredient. Examples of suitable capsules are disclosed in WO 2008/148601, WO 2008/148604, WO 2008/148646, WO 2008/148650, WO 2008/148656, WO 2008/148834, WO 2011/141532, WO 2011/141535, WO 2013/072239, WO 2013/072297, WO 2013/072326, WO 2015/044400. The capsule may be of the variety commercialised by Nespresso under the brand Vertuo. The capsule may include or be made of a soft and/or tearable material by exposure to the extraction liquid e.g. to water. Examples of such capsules are described in greater details in WO 2023/051967, WO 2023/052349, WO 2023/052350, WO 2023/052352, WO 2023/072997, WO 2023/104711 and WO 2023/104712. When reference is made in the present description to an orientation or position relative to the machine or parts thereof, e.g. “above” or “below” or “vertical” or “horizontal”, the orientation or position takes as a reference the position and orientation of the machine in operation to prepare a beverage unless specified otherwise. As used herein the term “cellulosic”, “cellulose- based” or “cellulosic material” may refer to conventionally woody (from soft wood and/or hard wood species) and/or non-woody materials. These materials may be bleached and unbleached and may include a regenerated or reconstituted cellulose. Examples of softwood are Pine, Spruce, Redwood etc. Examples of hardwood are Maple, Oak, Ash, Eucalyptus, Maple, Birch, Walnut, Beech etc. Examples of non-woody origin cellulose-based material are rice, manila hemp, sisal, jute, bamboo, maize, sugar cane, sugar cane residues (bagasse), banana peels. coffee ground. As used herein the term “natural cellulosic material” may refer to conventionally woody materials or non-woody materials, which are not regenerated. As used herein the term “reconstituted or regenerated cellulosic material” may refer natural cellulosic material subject to processing that comprises reconstitution or regeneration, examples include rayon and lyocell. As used herein the term “wood pulp” may refer to a lignocellulosic fibrous material, which may be prepared by mechanical or chemical separation of cellulose fibers from one or more of wood, fiber crops, paper, or rags. As used herein the term “wet formed” may refer to a process of forming from an aqueous solution of fibers. The aqueous solution of fibers may be heated and pressed in a mold to set the material and remove water therefrom. As used herein the term “dry formed” may refer to a process of forming not using aqueous solution of fibers. As used herein the term “wood pulp-based” may refer to the material or a portion of material forming the container which is one or more of: porous; fibrous; cellulosic; formed of cellulosic material; formed of natural cellulosic material; formed of reconstituted or regenerated cellulosic material; non-woven; is composed entirely of or is a composition of wood pulp and is wet or dry formed. A thickness of the wood-based material may be 0.08 mm to 0.90 mm, for example between 0.10 mm and 0.75 mm or generally about 0.15 mm to 0.5 mm. The wood- based material may be 200-400 gsm. Generally, the term “biodegradable” may be understood as meaning that a material is capable of being decomposed by bacteria or other biological means. The expression “biodegradable material” may be understood as any material that can be broken down into environmentally innocuous products by (the action of) living things (such as microorganisms, e.g. bacteria, fungi or algae). This process could take place in an environment with the presence of oxygen (aerobic) and/or otherwise without presence of oxygen (anaerobic). This may be understood, for example, as meaning that composting can be carried out without reservation. In particular, at the end of a composting process there are no residues of the material, which may be problematic for the environment, or any non-biodegradable components. Generally, the term “compostable” may be understood as meaning that a material may be substantially broken down into organic matter within a few weeks or months when it is composted. At the end of a composting process, the earth may be supplied with nutrients once the material has completely broken down. International standards, such as EU 13432 or US ASTM D6400, provide a legal framework for specifying technical requirements and procedures for determining compostability of a material. For instance, according to these standards, compostable materials must be biodegradable and disintegrable, i.e. fragmentation and invisibility in the final compost, and must not have negative effects on the composting process and quality. Composting may be accomplished in home composters and/or industrial composting sites. Defined conditions relating to wind, sunlight, drainage and other factors may exist at such sites. Biodegradation can be tested following standards such as ISO 14855, ISO 17556 or ISO 14851. For example, one of the tests requires that – in order to be considered as being “industrially compostable” - at least 90% of the material in question is biologically degraded under controlled conditions in 6 months. Similar tests exist also to enable home composting certification. For “home compostable” requirements, home- compostable materials may be composted in home composters, such as compost barrels or a home compost bin over a period of weeks or months (e.g. at least 90% degradation of materials in 12 months at ambient temperature). As a result of the composting process, the home-compostable materials may be converted into a nutrient-rich soil. Thus, a home-compostable container can be simply disposed in a home-compost pile after its use. The above materials can have a “material composition” exhibiting a constitution, combination and/or arrangement of (different) materials, which preferably form (altogether) a (uniform) structure, such as the container or a section thereof. Further features and advantages of the invention will appear in the detailed description and in the claims and in the drawings. Brief Description of the Drawings The invention will now be described with reference to the schematic drawings, wherein: - Figure 1 illustrates, partly schematically, a particular embodiment of a capsule seat of a machine according to the invention, the seat having first and second capsule enclosure parts in a proximate position holding a capsule for processing it; - Figure 2 illustrates the capsule seat and capsule of Fig. 1 with the first and second capsule enclosure parts between the proximate and a distant positions; - Figure 3 shows the capsule seat and capsule of Fig. 1 with the first and second capsule enclosure parts in the distant position; - Figure 4 illustrates the capsule seat of Fig. 1 after returning to the proximate position without capsule; - Figure 5 shows an enlarged view of the first enclosure part of the seat of Fig. 1, a first cooperating face of the enclosure part extending over a first capsule face; - Figure 5a is an enlarged view of a detail X of Fig. 5; - Figure 6 shows outlet openers to be associated with the seat outlets as illustrated in in Figs 5, 8 and 10; - Figure 7 shows a longitudinal cross-section of a machine for preparation a beverage and fitted with the capsule seat; Figure 8 illustrates a cooperating face of the first capsule enclosure part shown in Fig. 1, the cooperating face being associated with the seat outlets and outlet openers as well as a seat inlet;- Figure 9 shows an alternative embodiment of the first capsule enclosure part shown in Fig. 1;- Figure 10 is an enlarged view of a detail Y of Fig. 8;- Figure 11 shows a further embodiment of outlet openers to be associated with the seat outlets as illustrated in Figs 5, 8 and 10; and- Figure 12 is an enlarged view of a detail Z of Fig. 11. Detailed description The invention is now described with reference to the particular embodiment illustrated in Figs 1 to 10, Figure 9 illustrating a variation according to the invention. In this embodiment, a machine 1 is configured for preparing a beverage from an ingredient contained in a capsule 100 by supplying an extraction liquid, e.g. water, into such capsule, for instance from a liquid source 2 via a liquid driver 3 and thermal conditioner 4. Typically, machine 1 includes a source of extraction liquid, e.g. water, for example in a tank 2. Machine 1 may incorporate a pump 3 for driving the extraction liquid from source 2 to extraction module 10,20 e.g. via a temperature conditioner 4, e.g. an extraction liquid heater and/or cooler. Machine 1 has a machine outlet 5 configured to dispense beverage externally towards an area 6 for placing a user-recipient 9, such as a cup or a mug. Machine 1 incorporates a seat 10,20 for holding such capsule 100 during beverage preparation. Seat 10,20 has: - a seat liquid inlet 14,14’ configured for delivering the extraction liquid to such capsule 100, such as a liquid inlet 14,14’ associated with one or more capsule inlet openers 14a,14a’; and - at least one seat outlet 15,15’ at capsule 100 during beverage preparation, seat outlet(s) 15,15’ being configured to guide beverage from capsule 100, Seat outlet 15,15’ is associated with a capsule outlet opener 15a,15a’, e.g. an opener delimiting a peripheral beverage passage 15d and/or an inside beverage passage 15d’’. Outlet opener 15a may extend out of seat outlet 15, or outlet opener 15a’ may be located at a distance from the or each seat outlet 15. Seat 10,20 may be connected to a motor to drive during beverage preparation seat 10,20 in rotation to centrifuge capsule 100 so as to mix the ingredient supplied with the capsule and the extraction liquid to form the beverage. machine 1 has a beverage passage 5’ extending from seat outlet(s) 15,15’ up to machine outlet 5. Such at least one seat outlet 15,15’, beverage passage 5’ and machine outlet 5 form an outflow path 5,15,15’ having a direction of beverage flow extending therealong and a flow cross-section transverse to the direction of flow along outflow path 5,15,15’. The flow cross-section along the direction of flow has a smallest cross-section, e.g. at such at least one seat outlet 15,15’, with a surface area of at least 4.5 mm2, such as at least 5 mm2, for example at least 7 mm2, e.g. at least 9 mm2. Optionally the surface area is of less than 20 mm2, such as less than 15 mm2, for example less than 12 mm2, e.g less than 11 mm2. Capsule 100 may thus include or be made of a soft and/or tearable material, such as a material that becomes soft and sicking and/or tearable by exposure to said extraction liquid e.g. to water. Capsule 100 may be made of biodegradable or compostable material. It is possible to use plastic or metal, e.g. aluminium, capsules 100. Machine 1 may include a plurality of such seat outlets 15,15’, such as a number of seat outlets in the range of 5 to 40 for example 10 to 35 e.g. 20 to 30. The plurality of seat outlets 15,15’ may be connected to the same machine outlet 5, for example via the same beverage passage 5’. The or each capsule outlet opener 15a,15a’ can have a capsule opening blade 15b configured to form a corresponding outlet slit in capsule 100 e.g. a blade 15b extending in a straight plan to form a straight outlet slit in capsule 100. Capsule blade 15b may form a cutting edge that has at least one cutting ramp, e.g. a pair of cutting ramps in a symmetrical or asymmetrical V- configuration. The or each capsule outlet opener 15a,15a’,15a’’ may be sized and positioned in seat 10,20 to form a corresponding outlet slit in capsule 100, the formed slit having: - a length of at least 1.5 mm, such as at least 1.75 mm, for example at least 2 mm, e.g. at least 2.25 mm; and - a width of at least 0.2 mm, such as at least 0.3 mm, for example at least 0.4 mm, e.g. at least 0.5 mm. The or each capsule outlet opener 15a,15a’,15a’’ may be sized and positioned in seat 10,20 to form a corresponding outlet opening in a membrane 101 of capsule 100. The or each capsule outlet opener 15a,15a’’ may project out of its associated seat outlet 15 towards and into capsule 100 so as to form a corresponding outlet opening in such capsule 100 when held by the seat 10,20 during beverage preparation. The or each capsule outlet opener 15a, e.g. a or the opening blade, may have a foot 15c in the corresponding seat outlet 15, foot 15c being located behind a capsule opening extremity 15b that is configured to enter capsule 100, opening extremity 15b having a maximum cross-section that is larger than a maximum cross-section of the corresponding seat outlet 15. Capsule outlet opener 15a may be substantially spear-shaped or halberd-shaped. The or each capsule outlet opener 15a’, such as a frusto conical or frusto pyramidal piercer e.g. with a concave base, can project at a distance from the or each seat outlet 15’ so as to form a corresponding outlet opening in such capsule 100 when held by seat 10,20 during beverage preparation. Seat 10,20 around such seat outlet(s) 15,15’ may be configured to hold counter-outflow a capsule wall, such as a capsule membrane 101, of capsule 100 around capsule outlet opener 15a,15a’,15a’’ during beverage preparation, the or each seat outlet 15,15’ having a surface area at the capsule wall in the range of 9 to 12 mm2, such as 10 to 11 mm2. Seat liquid inlet 14,14’ and such at least one seat outlet 15,15’ can be positioned in seat 10,20 to face a same face, e.g. a same membrane 101, of capsule 100 when held by seat 10,20. Seat liquid inlet 14,14’ can be associated with one or more capsule inlet openers 14a,14a’. Seat liquid inlet 14,14’ can be associated with such one or more capsule inlet openers 14a,14a’, such as with 2 to 6 e.g. 3 to 4 inlet openers e.g. surrounding the seat liquid inlet 14,14’. Such one or more capsule inlet openers 14a,14a’ can be sized and positioned in seat 10,20 to form a corresponding inlet opening in membrane 101 of capsule 100. Seat 10,20 may include a first capsule enclosure part 10 and a second capsule enclosure part 20 movable relative to each other between a proximate position for enclosing in an enclosure 30 formed by parts 10,20 capsule 100 to process it so as to prepare a beverage therefrom and a distant position for inserting capsule 100 into enclosure 30 and removing capsule 100 from enclosure 30, e.g. towards a used capsule collector 7. First and second capsule enclosure parts 10,20 may be movable relative to each other by an actuator, such as a motor or a handle 60. One enclosure part 10 of first and second enclosure parts 10,20 may bear at least one seat outlet 15,15’ associated with capsule outlet opener 15a,15a’ and optionally seat liquid inlet 14,14’, e.g. associated with capsule inlet opener(s) 14a,14a’. Machine 1 may incorporate a capsule removal arrangement 40,50 for assisting removal of such capsule 100 when first and second parts 10,20 are brought from the proximate to the distant position. First capsule enclosure part 10 can have a first cooperating face 11 configured to extend over a first capsule face 101 and/or second capsule enclosure part 20 can have a second cooperating face 21 configured to extend over a second capsule face 102. For example, capsule 100 has a lateral face 103 extending between first and second capsule faces 101,102, e.g. a cylindrical and/or conical and/or spherical lateral face 103. Capsule removal arrangement 40,50 may include a first pusher 40 with a first pusher face 41 for contacting and pushing first capsule face 101 away from first cooperating face 11 and/or a second pusher 50 with a second pusher face 51 for pushing second capsule face 102 away from second cooperating face 21. For example first cooperating face 11 extends around first pusher face 41 and/or second cooperating face 21 extends around second pusher face 51. In the proximate position of first and second capsule enclosure parts 10,20:- first pusher face 41 and first cooperating face 11 may have a surface area ratio of at least 0.1, for instance at least 0.33, such as at least 0.5, optionally at least 0.5, e.g. at least 0.66 or at least 0.75; and/or at most 10, for instance at most 5, such as at most 3, optionally at most 2, e.g. at most 1.5 or at most 1.33; and/or- second pusher face 51 and second cooperating face 21 can have a surface area ratio of at least 0.05, such as at least 0.065, for example at least 0.08; and/or at most 0.2, such as at most 0.15, e.g. at most 0.10. At least one face of first and second pusher faces 41,51 can be substantially flush with corresponding cooperating face 11,21 when first and second capsule enclosure parts 10,20 are in the proximate position with capsule 100 in enclosure 30. When first and second capsule enclosure parts 10,20 are in the proximate position with capsule 100 in enclosure 30: - at least one face 41 of first and second pusher faces 41,51 may be convex and delimit a concave part of enclosure 30; and/or - at least one face 51 of first and second pusher faces 41,51 can be concave and delimit a convex part of enclosure 30. At least one of first and second pusher faces 41,51 may have a blunt shape towards an inside of enclosure 30 and/or may be free of any capsule-opening sharp protrusion extending towards the inside of enclosure 30. At least one of first and second pusher faces 41,51 may be connected to a deformable 54 that extends entirely substantially within a planar or incurved shape defined by and extending from such at least one of first and second pusher faces 41,51. At least one face 51 of first and second pusher faces 41,51 may be joined to its cooperating face by a deformable membrane 54 that substantially extends over a shape of the corresponding capsule face 102 in the proximate position of first and second capsule enclosure parts 10,20. Membrane 54 can be moved by an actuator 50a, e.g. an actuator rod, fixed to such one face 51, for example to a central part of face 51. While such capsule face 102 is being pushed away, membrane 54 may be arranged to be spaced from corresponding capsule face 102 or “peeled-off”, e.g. progressively “peeled-off”, from corresponding capsule face 102. At least one face 41 of first and second pusher faces 41,51 may be made of rigid material and may have a shape that substantially matches a shape of corresponding capsule face 101 before reaching enclosure 30 or deviates thereto by an angle of less than 45 deg., such as less than 30 deg, and/or of more than 5 deg, such as more than 10 deg, e.g. more than 15 deg. At least one face 41 of first and second pusher faces 41,51 can extend in a flat and/or curved plane, the curved part (if any) of the plane having a curvature radius that is larger than a radius of a curved periphery of first capsule face 101 and larger than a radius of a curved periphery of second capsule face 102. At least one pusher 50 of first and second pushers 40,50 may be driven by corresponding capsule enclosure part 20 when moved out of the proximate position and then stopped by a machine part 65 before corresponding capsule enclosure part 20 reaches the distant position. Pusher face 51 of such at least one pusher 50 may maintain or immobilize capsule 100 while corresponding capsule enclosure part 20 is further moved to reach the distant position. For example, pusher face 51 of such at least one pusher 50 is urged back by inserting a further capsule 100 into enclosure 30 while corresponding capsule enclosure part 20 is moved back into the proximate position. First capsule enclosure part 10 and second capsule enclosure part 20 in their proximate position may be connected to a motor to drive enclosure parts 10,20 in rotation so as to centrifuge in enclosure 30 capsule 100 to mix the ingredient and the extraction liquid so as to form the beverage. Further possible implementation details of machine 1 are disclosed in WO 2023/118244, WO 2023/118245, WO 2023/118246, WO 2023/118247, WO 2023/118248, WO 2023/118249 and PCT/EP2023/059650.