Patent Application
20170367526
The present technology is directed generally to coffee makers that produce coffee via rapid extractions and/or multiple extractions from a single set of grinds, and associated systems and methods. Results can include flavorful coffee that requires fewer grinds to produce.
Coffee has been a commonly-consumed beverage for many years. Over the course of time, many techniques have been developed to brew coffee, with each having its own advantages and disadvantages. For example, siphon coffee brewers were developed in the 1830's and were known to produce flavorful coffee, with little bitterness. However, the siphon brewers typically required a long extraction process, which made them impractical for busy coffee shops. Percolators were initially developed in the 1800's, and became popular in the first half of the twentieth century. Percolators also produce flavorful coffee, unless the brewed coffee is left on high heat for too long a period of time, in which case the coffee can acquire a bitter taste. Percolators have largely been replaced with drip coffee makers, which are simple and produce acceptable coffee. Other representative coffee makers include the Aeropress® and Steampunk coffee maker.
One drawback associated with the foregoing types of coffee makers is that none adequately combine low cost with high speed and efficient use of coffee beans. Consumer demand for flavorful, non-bitter coffee has increased over the past several decades, while the resources required to grow high quality coffee beans have become more scarce, particularly in view of environmental concerns associated with coffee plantations. Accordingly, there remains a need for coffee makers and associated processes that meet the foregoing objectives of low cost, high speed, and high quality.
The present technology is directed generally to coffee makers configured to brew coffee via multiple coffee extractions, and/or accelerated extractions, and associated systems and methods. Such coffee makers can be suitable for residential and/or commercial purposes depending on the particular embodiment. Specific details of several embodiments of the disclosed technology are described below with reference to particular, representative configurations. In other embodiments, the disclosed technology can be practiced in accordance with coffee makers having other configurations. Specific details describing structures or processes that are well-known and often associated with coffee makers, but that may unnecessarily obscure some significant aspects of the presently disclosed technology, are not set forth in the following description for purposes of clarity. Moreover, although the following disclosure sets forth several embodiments of different aspects of the disclosed technology, several other embodiments of the technology can have configurations and/or components different than those described in this section. As such, the present technology may have other embodiments with additional elements, and/or without several of the elements described below with reference to
Aspects of the present technology are generally directed to: (a) multiple coffee extractions; (b) accelerated extractions; (c) removable brew chambers; and (d) controllers and methods associated with the foregoing techniques and devices. Each of the foregoing aspects can include several embodiments, which can be combined with embodiments of the remaining aspects in any of a variety of suitable manners. For example, a multiple extraction process generally includes using the same set of coffee grounds to brew multiple quantities of coffee during a corresponding multiplicity of brew cycles. During the brew cycle, a solvent (typically hot water, but cold water can be used for cold brewed coffee) is in liquid communication with the coffee grounds. Typically, fresh water is used for each cycle, but in some embodiments, the process can include re-using brewed coffee from a prior cycle. Typically, one extraction (of the multiple extractions) is completed before the next brew cycle is started. However, in some embodiments, the extraction process for one cycle can overlap with the brewing process for the next.
Accelerated extractions can, in several embodiments, be used for one or more of the multiple extractions described above. An accelerated extraction generally refers to an extraction force that is applied to a quantity of brewed coffee at a particular point in time that was not applied just prior to that point in time, in order to extract the brewed coffee from the grinds. Representative techniques include applying pressure (e.g., pneumatic pressure, hydraulic pressure, or mechanical pressure, for example, with a French press) applying a vacuum, using a siphon process, using centrifugal force and/or opening a previously-closed valve to allow brewed coffee to descend under the force of gravity. In at least some embodiments, combinations of the foregoing techniques are used to extract or separate the brewed coffee from the coffee grinds used to form the brewed coffee.
The foregoing processes can be controlled to accurately produce and repeat the timing sequences associated with the processes. The processes can be controlled mechanically, for example, with a mechanical clock mechanism that mechanically or electromechanically operates valves, servos, and/or other actuatable elements. In another embodiment, a digital controller (e.g., a computer or computer-based system) directs the processes used to conduct the coffee brewing and extraction methods. For example, the computer or controller can include computer-based, e.g., programmable, instructions that are coupled to electromechanical valves, servos, and/or other actuators. In particular embodiments, the multiple extractions conducted without the aid of an accelerated extraction device are complete, meaning that the results of one brew cycle are completely extracted (or nearly completely extracted) from the bed of grinds before the next brew cycle begins. In another representative embodiment, in which an accelerated extraction device is implemented, one extraction process may be only partially completed before the next brew cycle begins on the same bed of grinds.
As noted above, several embodiments of the disclosed technology may take the form of computer-executable instructions, including routines executed by a programmable computer or controller. Those skilled in the relevant art will appreciate that the technology can be practiced on computer or controller systems other than those shown and described below. The technology can be embodied in a special-purpose computer, controller, or data processor that is specifically programmed, configured or constructed to perform one or more of the computer-executable instructions described below. Accordingly, the terms “computer” and “controller” as generally used herein refer to a suitable data processor and can include internet appliances and hand-held devices, including palm-top computers, wearable computers, cellular or mobile phones, multi-processor systems, processor-based or programmable consumer electronics, network computers, mini computers and the like. Information handled by these computers can be presented at any suitable display medium, including a liquid crystal display (LCD).
The present technology can also be practiced in distributed environments, where tasks or modules are performed by remote processing devices that are linked through a communications network. In a distributed computing environment, program modules or subroutines may be located in local and remote memory storage devices. Aspects of the technology described below may be stored or distributed on computer-readable media, including, magnetic or optically readable or removable computer discs, as well as distributed electronically over networks. Data structures and transmissions of data particular to aspects of the technology are also encompassed within the scope of the present technology.
As shown in
In a particular embodiment, the brew chamber 110 can include one or more side walls 111 (e.g. a continuous circular cylindrical or conical side wall 111), and a lower surface 112 (e.g. a sloped or canted lower surface 112), and can house the filter device 130. The boiler 160 can include (or can be coupled to) a water source 161, and can further include a heat source 162 (for heating the water provided by the water source 161), and a water inlet conduit 163 that directs the heated water into the brew chamber 110. Brewed coffee follows a fluid flow path that passes through the filter device 130, through a chamber connector 114 (that connects the brew chamber 110 to the coffee chamber 120) and into the coffee chamber 120 via an optional flow tube 125. Accordingly, the fluid flow path joins and includes the brew chamber 110 and the coffee chamber 120.
In a particular embodiment, the filter device 130 encloses an extraction area A1. For example, depending upon the volume of water that the brew chamber 110 is configured to handle, the extraction area A1 can be about 113 in.2 (corresponding to a round filter device 130 having a diameter of 12 inches). In other embodiments, the extraction area A1 can be about 20 in.2 or 38 in.2 (corresponding to filter devices 130 having diameters of about 5 inches, or 7 inches, respectively). In any of these embodiments, the relatively large area A1 allows a given volume of coffee grinds to be spread in a relatively thin layer over the filter device 130. This in turn can increase the speed with which brewed coffee is extracted through the filter device 130, and/or can reduce the likelihood that extended contact between the brewed coffee and the coffee grinds will produce a bitter-tasting coffee.
The system 100 can include a gas port 115 in fluid communication with the coffee chamber 120. In a particular aspect of this embodiment, the gas port 115 can selectively be coupled to an accelerated extraction device, for example, a pressure differential device 105 that produces a pressure differential between the brew chamber 110 and the coffee chamber 120. The pressure differential device 105 can include a vacuum source 101 and/or a pressure source 102 coupled to a first valve 141a. The vacuum source 101 is configured to draw a significant negative pressure on the coffee chamber 120, causing the brewed coffee to rapidly pass from the brew chamber 110 through the filter device 130 and into the coffee chamber 120. Accordingly, the vacuum source 101 is a representative example of a pressure differential device 105 that produces a relatively high pressure differential (e.g., at least 60 torr in some embodiments, and at least 150 torr in further particular embodiments) between the brew chamber 110 and the coffee chamber 120. In another embodiment, described later with reference to
In a particular embodiment, the coffee chamber 120 can be positioned below the brew chamber 110, as shown in
The coffee chamber 120 can have one or more side walls 121 (e.g. a conical side wall 121) and a base 122. In a particular embodiment, the system 100 is supported on the base 122 and in other embodiments, the system 100 can include other supports. For example, the system 100 can include an outer shell (e.g., a metal case or a plastic case) to provide support for the system 100. The outer shell can also serve a cosmetic purpose, e.g., by improving the outward appearance of the system 100. In at least some of these embodiments, the coffee chamber 120 includes the coffee outlet 123 and can further include a second valve 141b through which the brewed coffee is directed out of the system 100 after the brewing and extraction processes have been completed. In other embodiments, the coffee chamber 120 can serve as a carafe. Accordingly, the coffee chamber 120 need not include an outlet 123. Instead, the coffee chamber/carafe 120 can be removed from the system 100 (e.g., by separating it from the brew chamber 110) and the coffee can be poured out from the top of the coffee chamber/carafe 120.
In one embodiment, the processes for making coffee using the system 100 can be completed manually, e.g., via mechanical devices. In another embodiment, the system 100 can include a controller 140 for automatically controlling some or all of the processes used to make the coffee. The controller can include hard-wired circuits, and/or can be programmable. For example, the controller 140 can include a processor, memory and suitable input/output facilities. Accordingly, the controller 140 can receive sensor signals 142 (e.g. corresponding to system temperatures, pressures, flow rates and/or other suitable parameters) and can receive user inputs via a user input device 143 (e.g., buttons, a keyboard, touch screen, and/or other suitable device). Based on the received inputs, the system 100 can provide user outputs to a user output device 145 (e.g. a display panel) and it can provide system commands 144. The system commands 144 can automatically direct (e.g., activate, deactivate and/or modulate) the system components, e.g., the valves 141a, 141b, the boiler 160, the vacuum source 101 and/or the pressure source 102. The automated or partly automated processes available via the controller 140 can reduce the operators workload and/or can improve the precision and/or consistency of the brewing and/or extraction processes.
Prior to the first phase, process portion 201 includes placing ground coffee in a brew chamber. In addition to standard grind sizes used by existing commercially available batch brewers, the coffee can be finely ground, for example, to a median diameter of from about 200 μ to about 600 μ, or about 320 μ to about 400 μ, about 335 μ, or about 200 μ. These diameters are significantly smaller than the 800 μ diameter used in standard drip processes. The coffee can be spread thinly in the brew chamber, e.g. to a depth of less than 0.7 inches, or from about 0.2 inches to about 0.6 inches, or about 0.3 inches to about 0.5 inches, or about 0.4 inches, as measured after brewing. In general, spreading the coffee so as to have a post-brew depth of less than one inch can reduce the likelihood for the resulting coffee to have a bitter taste. On the other hand, spreading the coffee to have a post-brew depth of less than 0.1 inches can produce a brew chamber width or diameter that occupies too much space in a typical commercial setting.
During the first phase (process portion 203), a volume of heated water is placed in the brew chamber. The water can be heated using a boiler or other suitable device and can enter the chamber from any suitable port or opening. In any of these embodiments, the volume of heated water is placed in intimate thermal and physical contact with the coffee grinds in the brew chamber. Optionally, process portion 205 can include agitating the coffee grinds and the hot water, for example, using a mechanical device and/or an aeration process.
The second phase 230 can include process portion 207, in which a volume of brewed coffee is extracted from the brew chamber into the coffee chamber. In a particular embodiment, a vacuum is applied to the coffee chamber to draw the brewed coffee into the coffee chamber, and in another embodiment, pressure is applied to the brew chamber to drive the brewed coffee into the coffee chamber. In yet another embodiment, pressure is applied to the brew chamber, in combination with vacuum applied to the coffee chamber. In any of these embodiments, the extraction process can be completed after the water in the brew chamber has completed the brew cycle (e.g., to extract flavor from the ground coffee), and can be completed in a short period of time (e.g., to prevent the brewed coffee from being in contact with the coffee grinds for too long, which can cause the coffee to taste bitter). Accordingly, the pressure differential between the brew chamber and the coffee chamber can be less than 60 torr or 150 torr (e.g., zero) during the first phase 220, and greater than 60 torr or 150 torr during the second phase 230. For example, the brew chamber can be at atmospheric pressure during the first phase 220. During the first phase 220, a small amount of brewed coffee can pass from the brew chamber to the coffee chamber under the force of gravity, but the pressure differential between the chambers will be less than 60 torr. The fineness of the grind used in the process (which can enhance the coffee flavor strength) can also reduce the amount of brewed coffee that may leak from the brew chamber 110 to the coffee chamber 120 during the brew cycle. This in turn improves the controllability and reproducibility of the brew process because all or virtually all of the coffee will spend approximately the same amount of time in the brew chamber. In general, the threshold pressure differential of 150 torr can be advantageous over the threshold value of 60 torr because the higher pressure differential value produces a faster extraction process.
In at least some embodiments, the process ends at process portion 207. Accordingly, the grounds placed in the brew chamber in process portion 201 are used once with a single volume of water to produce a corresponding single volume of coffee. In other embodiments, the same grinds can be used for multiple volumes of coffee. Accordingly, process portion 203, 205 (optionally) and 207 can be repeated in series, once, twice, three times or more to produce a combined volume of coffee in the coffee chamber, with the combined volume being formed from individual volumes of coffee, each of which has been brewed with the same set of grinds.
In addition to quickly extracting the brewed coffee from the brew chamber into the coffee chamber, the high pressure differential provided by the pressure differential device can dry the grinds in the brew chamber. As a result, the dry grinds can provide a better starting point for the second (and any further subsequent) brew processes. Therefore, the likelihood for the subsequent processes to produce a bitter-tasting coffee can be further reduced. In addition, the strong pressure differential can remove the majority of dissolved gasses from the coffee grinds, which may be trapped in the coffee beans used to produce the grind during the roasting process. As a result, in subsequent extractions following the first extraction, the grinds can have a significantly larger exposed surface area, and the water used during the subsequent extractions can contact the additional surface area, which is no longer blocked by gas.
In
As shown in
Once the brewing process (e.g., the initial brewing process) has been completed (which can take from about 5 seconds to about 5 minutes), the brewed coffee is removed from the brew chamber 110 and directed into the coffee chamber 120. For example, as shown in
The pressure differential draws the extracted coffee from the brew chamber 110 to the coffee chamber 120. Because the gas port 115 is located above the first volume 651a of extracted coffee, the extracted coffee that collects in the coffee chamber 120 is not sucked through the gas port 115 by the vacuum source 101. Representative extraction times of each extraction process can range from about 5 seconds to about 60 seconds, depending on factors that include the pressure differential level, the volume of coffee removed from the brew chamber 110 with each extraction, and the fineness of the coffee grind.
In another embodiment, also illustrated in
As shown in
With reference now to
The brew chamber 810 can further include a lid 817 having one or more retention elements 819 that keep it centered on the upper portion 816a. A corresponding water inlet conduit 863 can be built into the lid 817. In one embodiment, the lid 817 can be held in place with a clamp (similar to the clamp described below with reference to
Table 1 below illustrates representative results obtained using an apparatus generally similar to that described above with reference to
Each complete brew was performed using 43 grams of coffee and one liter of water, with a cloth filter. Each first pull or extraction used 400 mL of water, and each second and third pull or extraction was performed with 300 mL of water. The average height of the coffee grinds resting on the filter, after the brew process was complete, was approximately 0.4 inches. An additional set of results was obtained using a paper rather than a cloth filter for grind C. The results included a faster extraction process, with the second and third pulls at 20 seconds each, rather than at 40 and 60 seconds, respectively, for the high vacuum. When the medium vacuum was used, the extraction process was longer, including 40 seconds for the first pull, 70 seconds for the second, and 65 seconds for the third. The times in Table 1 are extraction times only. Corresponding brewing times were 40 seconds per cycle, prior to initiating extraction.
Table 2 below illustrates representative results obtained using another apparatus generally similar to that described above with reference to
Further, the average height of the coffee grinds resting on the filter, after the brew process was complete, was approximately 0.2 inches. The times in Table 2 (like those in Table 1) are extraction times only. Corresponding brewing times were 40 seconds per cycle, prior to initiating extraction.
Each of the foregoing tests produced a flavorful cup of coffee, notably lacking in bitterness. For purposes of comparison, Grind A (the coarsest grind) was also tested in a drip coffee brewer. The process took 7 minutes for 43 grams of grinds and one liter of water, and the coffee produced was markedly bitter. The height of the coffee grinds under these conditions, in a cone filter, was approximately two inches.
In at least some embodiments, it is expected that the foregoing times listed in Tables 1 and 2 can vary by ±5 seconds. Accordingly, a pull of 30 seconds can correspond to a range of from about 25 to about 35 seconds. As used herein, the term “about” when used in the context of pull times means within 2 seconds. In general, the term “about” means within 10%, as applied to temperatures, pressures, flow rates, and dimensions.
The system 1000 can include a brew chamber 1010 coupled to a coffee chamber 1020 via a chamber valve 1041b. Coffee grinds are placed in the brew chamber 1010. Brewed coffee is extracted through a filter (not visible in
The brew chamber 1010 receives water from a water source 1061, which is heated in a boiler 1060, and can be pressurized for flow into the brew chamber 1010 with a water pump 1065. A flow meter 1066 can be used to measure and/or modulate the flow of water through a corresponding water inlet conduit 1063 into the brew chamber 1010. The system can include one or more temperature sensors, for example, a temperature sensor 1067 positioned to measure the temperature of the water at the brew chamber 1010.
A pressure differential device 1005 provides vacuum and/or pressure to direct extracted coffee from the brew chamber 1010 into the coffee chamber 1020. The pressure differential device 1005 can create the required pressure differential via positive and/or negative pressure. One or more optional regulators 1003 and/or pressure differential valves 1041a control the introduction of vacuum or pressure provided by the pressure differential device 1005, and control the communication between the pressure differential device 1005 and the coffee chamber 1020 and/or the brew chamber 1010. In other embodiments, the regulator(s) 1003 can be eliminated, and instead, the pressure differential device 1005 can have fixed, known vacuum/pressure parameters for controlling the pressure differential between the brew chamber 1010 and the coffee chamber 1020. In any of these embodiments, the pressure differential device 1005 can include one or more components that apply a vacuum to the coffee chamber 1020 (as shown in solid lines), and/or one or more components that apply pressure to the brew chamber 1010 (as shown in dashed lines). A secondary pump 1004 can be coupled to the coffee chamber 1020, for example, to provide the agitation force described above with reference to
A representative process for using the system 1000 described above with reference to
Step 1: Program the controller 1040 to set brew parameters (e.g. temperature, water volume per brew/extraction cycle, vacuum/pressure strength and/or start and end times, agitation start and/or end times, and/or agitation strength). An operable combination of parameters is referred to as a “program”.
Step 2: Securely fasten a clean filter into the brew chamber 1010. Depending on the embodiment, this may include placing the filter in the brew chamber 1010, and securely clamping the filter in place to prevent grinds from passing through or around the corners of the filter during brewing, and to prevent the filter from overly warping if the coffee is agitated during the brew cycle. In representative embodiments, the force provided by the process of clamping the filter in place is higher than is used in conventional processes so as to withstand the higher pressure differential supplied by the pressure differential device 1005.
Step 3: Place a selected weight of ground coffee into the brew chamber 1010, resting the grind on top of the filter.
Step 4: Initiate the program at the controller 1040. If the controller 1040 includes a touchscreen display, initiating can include pressing a “Start” button. In other embodiments, the start button can include a physical button and/or another suitable interface.
Step 5: The controller 1040 directs water from the water source 1061 to the boiler 1060, where the water is heated to a selected temperature specified in the program (or if water is not provided through a water line, water may be manually placed into boiler, with heating commencing once the water has been placed in the boiler).
Step 6: The water reaches the temperature programmed into the controller 1040. In representative embodiments, the temperature of the water is from about 195° F. to about 205° F. The temperature of the water can be controlled via a feedback device (e.g., a PID controller). In another embodiment, the water is allowed to come to a boil and then rest for pre-specified time to arrive at the programmed temperature. For example, the controller 140 can allow the water to come to a boil, rest for a pre-specified time, and then introduce the water without any specific feedback regarding the temperature of the water. For example, the water can be boiled and then rest for 30 seconds or the water can be heated instantaneously or nearly instantaneously to a programmed temperature, for example, using an induction heater. In at least some of these embodiments, the controller 1040 can direct the boiler 1060 to release a specified volume of heated water, e.g., via a valve. The amount of water can be set by the program. The released water passes into the brew chamber 1010 so as to be in contact with the coffee grinds. The total volume of water released into the brew chamber 1010 may be regulated by the flow meter 1066 placed between the boiler 1060 and the brew chamber 1010, or the valve can be time-actuated. Without a flow meter present, opening the water valve for a period of time specified in the program means that different water line pressures will lead to different volumes of water being dispensed. Accordingly, the flow meter 1066 can produce a relatively consistent dispensed water volume, despite different water line pressures present in different environments. In a further particular aspect of the foregoing embodiments, coffee within the brew chamber 1010 is prevented from exiting the brew chamber 1010 while the brewing process is underway, and only exits the brew chamber 1010 after a predetermined brewing period. In other words, the coffee does not proceed directly through and out of the brew chamber 1010, as it does in a typical drip coffee maker.
Step 7: The coffee brewing in the brew chamber 1010 is (optionally) exposed to agitation, via an air pump that introduces bubbles, and/or via another agitation mechanism, such as a mechanical stirrer, for an amount of time and at an intensity provided for in the program.
Step 8: The brew chamber 1010 is exposed to, acted upon, or subjected to a vacuum and/or an elevated pressure and/or another extraction accelerating force for an amount of time and at a level provided for in the program, evacuating the brew chamber of fluid. In a particular embodiment, nearly all the brewed coffee is evacuated (using a pressure source, vacuum source or both) from the brew chamber, leaving the nearly dry grinds resting on the filter. For example, the grinds can be dried to the point at which only 5-10% of the water initially added to the grinds remains in the grinds after the extraction process. In a representative process, the system shown in
Step 9: In particular embodiments, e.g., those embodiments that include multiple extractions from a single mass of coffee grinds, Steps 6-8 are repeated at least once, optionally with different parameters for time, vacuum force, water volume and/or other parameters, specified in the program for each repetition. Step 7 may or may not be used during any of the foregoing extraction processes, depending on factors that can include the type of coffee being brewed and/or the desired coffee flavor.
Step 10: Once the extraction process has been repeated a suitable number of times, as specified in the program, the brewed coffee that has been evacuated into the coffee chamber is ready for consumption. The coffee may be removed from the coffee chamber via any of a variety of suitable mechanisms, depending on the design of the coffee chamber. For example, coffee can be removed via a spout, or the coffee chamber can be a removable thermal carafe, allowing the user to remove the coffee chamber completely once brewing is complete. The carafe can be used to pour the brewed coffee into a cup.
Step 11: Once the entire brewing process is complete, the filter can be removed from the brew chamber, along with the used grounds. Depending on the filter design, the filter may either be cleaned for later use, or disposed of.
Step 12: With the filter removed, the brewing device can be cleaned. Cleaning can include manual cleaning using traditional cleaning methods, such as sponge and soap, or can include repeating Steps 4-10 above, without the introduction of coffee grounds. The introduction of heated, agitated water into the system without coffee grounds will have the effect of dissolving residual brewed coffee and eliminating grinds that were not eliminated upon the removal of the filter.
One feature of at least some of the foregoing embodiments described above is that a single quantity of brewed coffee can be made by extracting multiple volumes of heated water through the same set of coffee grinds. An advantage of this approach, when compared to conventional approaches, is that the amount of coffee grinds required to produce a cup of flavorful coffee can be reduced significantly. For example, it is expected that the foregoing technique can reduce the required amount of coffee beans by approximately 30% or more, by weight, when compared to conventional drip and/or other coffee making processes. Furthermore, the multiple extraction process allows smaller, more carefully controlled quantities of water to go through the brewing process, which further improves the uniformity of contact between any quantity of water and the coffee grinds. Performing multiple short duration extractions is also less likely to produce bitter coffee than one long-duration extraction, and adding multiple volumes of fresh solvent to the coffee is more likely to extract additional flavor compounds that would otherwise remain unextracted. This result can be based upon a number of factors. For example, bitters (e.g., primarily tannins) are typically extracted from the coffee grinds later in the extraction process. Accordingly, by adding fresh solvent (e.g., water), the brew or extraction process is restarted with each new controlled quantity of solvent added to the grinds. Accordingly, as more of the total brewing/extraction time is spent early in the brewing process for each of the multiple extractions, bitters are less likely to be extracted. By adding a new volume of water for each of the multiple extractions, a new phase partition equilibrium (solid/liquid) begins. In particular, there are no dissolved materials in the newly-added water at the beginning of each new extraction cycle. For each new cycle, the phase partitioning process begins again, with the same compounds partitioning into the new volume of water at set times. Because the bitters are released from the coffee grounds at a generally fixed point in time after the brewing process starts, the brewing process can be deliberately stopped before that point is reached. Furthermore, multiple extraction processes, each using the same set of grinds and a new volume of water, can produce more organic flavor compounds in the resulting coffee.
Another feature of at least some of the foregoing embodiments is that a relatively large pressure gradient can be formed between the brewing chamber and the coffee chamber. As discussed above, the pressure gradient can be formed by pressurizing the brewing chamber and/or applying a vacuum to the coffee chamber. A result of the large pressure gradient is that the brewed coffee is quickly extracted from the brewing chamber, therefore allowing more precise control over the amount of time that the brewed coffee is in direct contact with the coffee grinds. This in turn allows the operator to produce flavorful coffee without the coffee becoming bitter as a result of spending excessive time in contact with the coffee grinds. For example, the large pressure gradient can pull a thin layer of water quickly through the filter so that all or a significant portion of the coffee grinds are in contact with water for approximately the same amount of time. By contrast, conventional gravity extraction processes typically are not as amenable to the level of control outlined by the processes described above. It is difficult to brew coffee in conventional manners to produce larger quantities of coffee without a bitter taste. The large pressure gradient can be particularly useful for finer grinds, for which existing methods either are incapable of brewing fast enough to prevent high bitterness levels, or are incapable of producing a brew at all, for example, due to the filter clogging when used with very fine grinds.
Still another feature of at least some of the foregoing embodiments is that the brewing chamber and in particular, the filter, can have a large surface area when compared with the volume of coffee grinds that are placed on the filter and/or the volume of coffee produced. The result is that the coffee grinds can form a relatively thin layer of coffee over the filter. This in turn results in a more uniform brew. For example, each portion of hot water passing through the bed of coffee grinds passes through coffee grinds that have been exposed to approximately the same quantity of water. The coffee produced in this manner has a concentration and taste similar to that of drip coffee, without the bitterness associated with other conventional coffee brewing techniques, and is produced in a shorter period of time than typical drip techniques. This is unlike conventional arrangements in which the bed of coffee grinds is relatively deep. In such an arrangement, some water passes through only a portion of the total depth when extraction begins, and other water passes through the entire depth, a problem that is often associated with making espresso, and which is referred to as channeling. Also, for example, utilizing a relatively thin layer of coffee over the filter can improve the controllability and reproducibility of the brew process because all or virtually all of the coffee will spend approximately the same amount of time in the brew chamber. In addition, a thin layer of coffee grinds can significantly accelerate the extraction process by reducing the barrier through which coffee must travel to enter the coffee chamber upon extraction.
Still another advantage of the foregoing feature is that the large filter surface area can reduce or eliminate the likelihood for clogging during the extraction process. In particular, the relatively large filter surface area (e.g., in combination with the large pressure differential created by the pressure differential device) can allow the system to brew from finer grinds (e.g., less than approximately 400 microns) without clogging, e.g., because for a fixed weight of grinds, a larger filter surface area will result in a shallower grind bed, and hence create less fluidic resistance to water flowing through the grinds. Finer grinds can typically produce more flavor per unit of extraction time, because they have greater surface area for a given weight of grind and hence organic compounds from the grinds can be extracted more quickly into solvent (e.g. water), but can also produce bitters more quickly. Accordingly, controlling the timing of individual brew cycles can allow the system to consistently and reproducibly produce flavorful, non-bitter coffee.
Still another feature of at least some of the foregoing embodiments is that the system can include an active device that applies a vacuum or a positive pressure to the brewing chamber to direct brewed coffee into the coffee chamber. Unlike conventional siphon devices, which typically rely on a small vacuum produced by condensing and/or cooling air and/or water vapor in the coffee chamber, the foregoing arrangement produces significantly higher vacuums and/or pressures, which can expedite the process for withdrawing coffee from the brew chamber, reducing or eliminating the bitterness that can result from the brewed coffee spending too much time in contact with the coffee grounds.
A representative process includes placing coffee grinds into the brew chamber by the operator or via an automatic coffee dispensing system, and introducing water via a water introduction device, which is directed by a controller. The coffee is then brewed according to the system's applicable brew methodology (e.g. drip, siphon, etc.). The resulting brewed coffee is transferred from the brew chamber to a coffee chamber via an applicable methodology (for example, in a drip coffee setup, the coffee drips into the coffee chamber via gravity). Once the coffee has completed or approximately completed brewing and the flow of brewed coffee from the brew chamber to the coffee chamber has completely or approximately stopped as a result, the controller then causes the water introduction device to introduce a second volume of water into the brew chamber, and the applicable brewing process is re-initiated one or more times using the same set of previously-used coffee grinds. The brewed coffee from each such extraction of the same coffee grinds is combined to form the final beverage.
The foregoing process can produce one or more significant practical results. For example, by allowing a set of coffee grinds to undergo an entire brew process (e.g., from the introduction of water and subsequent brewing to the flow of brewed coffee from the brew chamber to the coffee chamber, removing all or at least a significant amount of the solvent from the brew chamber), and then adding a fresh volume of water to the same coffee grinds, a new solid-liquid phase partition equilibrium is established by the introduction of the fresh solvent, changing the extraction and, if desired, reducing the total extraction of bitter/astringent compounds. By combining multiple brews made from the same grinds using this method, a given weight of coffee grinds is used to produce a volume of brewed coffee for which the total dissolved solids is comparable to, or greater than, coffee brewed using a substantially greater mass of coffee grinds.
In a particular method (conducted, e.g., with an embodiment of the apparatus described above with reference to
The foregoing design is distinguished from a conventional pulse brewing drip system or a pre-infusion system, which are other methods that can be used to increase the total dissolved solids of brewed coffee. For example, in the foregoing embodiment, the controller is programmed to specifically wait until the water has substantially completed brewing, whereas in a pulse brewing drip system, water is gradually introduced into the brew chamber in repeated cycles as the coffee is still brewing, and whereas in a drip or espresso pre-infusion system, a volume of water is added to the ground coffee to saturate the grinds with water prior to introducing the majority of the water into the brewing process. The intended effect is also different. Pulse brewing and pre-infusion are designed to saturate the grinds with water, so that they can absorb additional water more readily, and/or to increase the amount of contact time between the water and ground coffee, whereas the embodiment described above is expected to eliminate as much brewed coffee as possible from the coffee grinds by substantially completing the brew process before re-introducing water into the grinds. In other words, pre-infusion and pulse brewing methodologies introduce additional water during the brew process to ensure the grinds are constantly saturated with water, whereas the embodiment described above introduces water into the coffee grounds only once such grounds have substantially completed brewing, hence waiting until the moisture content of such grinds are substantially at their minimum during the brew cycle prior to re-introduction of water.
In order to facilitate brew times that are amenable to multiple extractions in the foregoing embodiment without resulting in excess bitterness, an operator can use 20-40% less coffee grounds, by weight, than amounts that would typically be utilized in a commercial setting to brew coffee via a grind basket of a given diameter. By using fewer grinds, water dispensed into a grind basket will substantially complete brewing faster, because the smaller amount of grinds present a lesser barrier for water to drip through, thus reducing the bitterness of each brewed volume of coffee. Although reduced brew times would otherwise translate into a weaker beverage, the foregoing design uses repeated extractions of the same coffee grounds, each at a reduced brew time, to increase flavor extraction.
(a) cause a water pump 1264, operating as a water introduction device, to direct a volume of water from a boiler 1260 into the lower chamber 1220,
(b) then direct the activation of a heating element 1262 acting upon the lower chamber 1220, causing the water to travel up through a brew tube 1214 into the upper chamber 1210 as a result of water vapor pressure buildup in the lower chamber 1220 caused by the heating of the water therein,
(c) then wait a pre-specified time, allowing the coffee to brew sufficiently in the upper chamber 1210,
(d) then direct the heating element 1262 to cool (e.g., by shutting off the heating element), causing the water vapor in the lower chamber 1220 to condense, forming a vacuum that causes the brewed coffee to descend from the upper chamber 1210 to the lower chamber 1220, via the brew tube 1214,
(e) then cause the descended brewed coffee 1251 to be released from the lower chamber 1220 to the coffee chamber 1290, by actuating a valve 1291 that creates a flow path and moves the brewed coffee from the lower chamber 1220 to the coffee chamber 1290,
(f) then introduce a second volume of water into the lower chamber 1220, and
(g) repeat steps (b)-(e) one or more times, hence allowing the brewing and extraction processes to repeat with a fresh volume of solvent.
Subsequently, the multiple volumes of brewed coffee are combined in the coffee chamber 1290, which can then be emptied by the operator, with the brewed coffee ready for consumption. In some embodiments, instead of adding fresh solvent to the grinds, the same volume of solvent is used when repeating steps (b)-(e).
Accordingly, the brew chamber 1310 can have a cavity for receiving coffee grinds, as well as an arrangement for preventing the coffee grinds from entering into the coffee chamber. One such arrangement includes a filter, e.g., a paper, cloth, or metal filter, as discussed above with reference to
In several of the embodiments described herein, the brew chamber or the coffee chamber, or any intermediate chamber anywhere along the flow path of the brewed coffee is coupled to an accelerated extraction device. The accelerated extraction device causes the brewed coffee to flow from the brew chamber to the coffee chamber at a rate that is higher than the flow rate (which may be zero) of the system prior to the activation of the accelerated extraction device. The accelerated extraction device may include, for example, a pressure source (positive or negative) such as a plunger, a pump, a vacuum piston, or a centrifuge, acting on a combination of brewed coffee and coffee grinds in the brew chamber, and extracting the brewed coffee. For example, the brewed coffee can be forced through a filter/porous material or compacted grinds. Compacted grinds can allow the use of an espresso-like large-hole filter. By activating an accelerated extraction device that includes a pressure source, brewed coffee is forced through a filter, rather than simply dripping through the filter by force of gravity, hence accelerating the extraction.
In another embodiment, the accelerated extraction device can rapidly remove brewed coffee from the brew chamber, after the brewed coffee has been separated from the coffee grinds, for example, via compaction. The accelerated removal may be achieved by pumping out the separated brewed coffee into the coffee chamber, or alternatively, pumping the brewed coffee into a secondary filtration vessel whereby the brewed coffee may undergo a second filtration operation. The second filtration operation may be desirable if some coffee grinds are still present in the brewed coffee, after the initial separation and prior to entering the coffee chamber. As this case demonstrates, the brewed coffee may travel through one or more other additional compartments that filter or otherwise process the brewed coffee prior to entering the coffee chamber.
In still further embodiments, the accelerated extraction device may implement other techniques to separate a fixed volume of brewed coffee from a given set of coffee grinds and introduce the brewed coffee into the coffee chamber in a manner that is faster than the separation rate prior to activating the accelerated extraction device.
The system 1300 includes a controller 1340 that has been configured to extract multiple volumes of brewed coffee from a fixed set of coffee grinds. The controller 1340 can be mechanical or electrical; for example, the controller can be a microcontroller that directs the action of the water introduction device and the accelerated extraction device electronically. A representative controller is configured to perform at least the following steps, in the following order.
(1) combine hot water with coffee grinds so that the water will brew coffee for some period greater than three seconds, e.g., cause the water introduction device to introduce water into the brew chamber (where the grinds have already been placed), or cause a grind dispenser to dispense grinds into the brew chamber (where the hot water has already been placed),
(2) cause the accelerated extraction device to accelerate the extraction of at least a portion (but not necessarily all) of the brewed coffee from the brew chamber into the coffee chamber, and
(3) cause the water introduction device to introduce additional water into the brew chamber, which will brew using the same coffee grinds from step 1 and later be combined with the coffee brewed in step 2 prior to serving.
(1) cause the water introduction device to introduce water into the brew chamber, where the water will brew coffee,
(2) allow all or a portion of the water to enter into the coffee chamber via a method that does not utilize an accelerated extraction device,
(3) cause the water introduction device to introduce additional water into the brew chamber, and
(4) cause the accelerated extraction device to extract at least a portion (but not necessarily all) of the additional brewed coffee from the brew chamber into the coffee chamber, combining with the coffee brewed in step 2 prior to serving.
Accordingly, the initial quantity of water can drip (or otherwise pass) through a set of coffee grinds, and the additional water can be rapidly extracted. Accordingly, the accelerated extraction device can accelerate a flow of coffee that would otherwise have a non-zero flow rate. To achieve certain coffee brew characteristics, it may be desirable to conduct a brief drip extraction at a low volume of water, followed by a one or more accelerated extractions. In this arrangement, it is not necessary for the accelerated extraction device to act upon the water/grinds more than once to achieve multiple extractions. In another embodiment of this arrangement, the steps can be reversed, e.g., the coffee formed from an initial volume of water is extracted in an accelerated fashion and the additional volume of water is allowed to extract via gravity or through other forces.
The disclosed systems are not limited to traditional coffee brewing device geometries. Instead, the brew chamber, coffee chamber, and accelerated extraction device can have a variety of suitable configurations/orientations with respect to one another in different embodiments. Furthermore, one or more additional brewing elements and/or brewing chambers may be present in the system, which can facilitate the process of brewing coffee. For example, the brew chamber can include an agitation device, as discussed above with reference to
Embodiments of the foregoing and following processes differ from espresso processes in one or more of multiple ways. For example, the size of the coffee chamber can be at least 200 mL. As another example, the disclosed processes include brewing the coffee, rather than allowing a continuous stream of water through it. As another example, the disclosed process can be achieved using significantly lower positive pressure than the 9-10 bars typically utilized in brewing espresso, or no positive pressure. In embodiments for which a continuous stream is run through the grinds, the stream is intermittent, yielding multiple extractions and hence creating multiple distinct solid-liquid phase partition equilibria.
(1) cause water to be introduced to the grinds via a water introduction device 1464 (e.g., a water introduction pump), taking in water from a boiler 1460,
(2) then allow the coffee to brew in the brew chamber 1410 until the grinds 1450 have been exposed to the water a sufficient amount of time to achieve the desired brew characteristics. Time spent brewing affects the character of the brewed coffee, including its strength, bitterness, and flavor profile,
(3) then, once this period has elapsed, direct a French press mesh filter 1412 to descend into the brew chamber 1410 via a piston 1490 (e.g., electrically controlled), with the combination of the French press mesh filter 1412 and the piston 1490 acting as the accelerated extraction device. This causes the brewed coffee to separate from the grinds (as shown in
(4) then causes a brewed coffee extraction pump 1401 to pump the brewed coffee, now separated from the grinds 1450, into a coffee chamber 1420, (5) then raise the French press mesh filter 1412 via the piston 1490, subsequently introducing a second volume of water into the brew chamber 1410 and onto the previously brewed, non-replaced coffee grinds 1450, and optionally agitating the grinds with an optional agitation device (see
(6) repeat steps 1-4 one or more times, to allow the extraction process to repeat with a fresh volume of solvent (water), and subsequently combine the multiple volumes of brewed coffee in the coffee chamber 1420, which can then be emptied by the operator, with the brewed coffee ready for consumption.
In another embodiment, the functions provided by the brewed coffee extraction pump 1401 and the water pump 1464 can be combined into a single pump that is selectively coupled to the boiler 1460 or the brew chamber 1410 via one or more valves under the control of the controller 1440.
(1) direct the pump 1664, serving as the water introduction device, to direct a volume of water from the boiler 1660 into the brew chamber 1610,
(2) then wait a pre-specified, pre-calculated time (e.g., for a given weight of grinds), after which the coffee has brewed sufficiently without any communication between the brew chamber 1610 and the coffee chamber 1620, after which a coffee flow path valve 1641 is actuated, opening a flow path between the brew chamber 1610 and the coffee chamber 1620,
(3) then wait a pre-specified, pre-calculated time (e.g., for a given weight of grinds), after which the water has substantially completed brewing by dripping into the coffee chamber 1620,
(4) then close the coffee flow path valve 1641 to close the flow path from the grind basket (brew chamber 1610) to the carafe (coffee chamber 1620),
(5) then introduce a second volume of water into the brew chamber 1610 to allow the extraction process to repeat with a fresh volume of solvent (e.g., water).
In the foregoing embodiment, the valve 1641 operates as an accelerated extraction device. Before the valve 1641 is actuated (opened), the brewed coffee 1651 is in liquid communication with the grinds 1650 in the brew chamber 1610. When the valve 1641 is opened, the pressure differential (created by the hydraulic head of the brewed coffee 1651 in the brew chamber 1610) forces the brewed coffee into the coffee chamber 1620.
(1) cause water to be introduced to the grinds 1750 via a water introduction pump 1764, acting as the water introduction device, taking in water from a boiler 1760,
(2) then allow the coffee to brew in the centrifuge 1711 until the grinds 1750 have been exposed to the water a sufficient amount of time for the desired brew flavor characteristics,
(3) then, once this period has elapsed, direct the centrifuge 1711 to spin at a sufficient rate to cause the brewed grinds 1750 to compress along the sides of the brew chamber 1710 (as shown in dashed lines), separating the brewed coffee 1751 from the compressed grinds 1750a,
(4) then cause a brewed coffee extraction pump 1701 to pump the brewed coffee 1751, now separated from the grinds 1750a, into a coffee chamber 1720, collecting in the coffee chamber,
(5) then subsequently introduce a second volume of water into the centrifuge 1711 combining with the previously brewed, non-replaced coffee grinds 1750, and optionally agitating the grinds with an optional agitation device (not shown) to distribute the grinds more evenly throughout the new volume of water/agitate during the brew cycle, and
(6) repeat steps 1-4 one or more times, hence allowing the extraction process to repeat with a fresh volume of solvent, and subsequently combining the multiple volumes of brewed coffee in the coffee chamber 1720, which can then be emptied by the operator, with the brewed coffee ready for consumption.
In a particular embodiment, the system 1800 can also include a locking mechanism 1870, shown schematically as a latch in
In particular embodiments, other aspects of the system 1800 can be automated, in addition to or in lieu of automating the locking mechanism 1870. For example, the system 1800 can include an automated driver 1890 that automatically attaches and detaches the brew chamber 1810. In a particular aspect of this embodiment, the automated driver 1890 can include a lead screw 1891 that drives the brew chamber into engagement with a coupling at the end of the coffee inlet conduit 1823, as indicated by arrow A, and out of engagement with the coffee inlet conduit 1823, as indicated by arrow D. One or more rails or other guide elements can guide the motion of the brew chamber 1810 and prevent it from rotating under the torque imparted by the lead screw 1891.
The system 1800 can include a boiler or water heater 1860 that heats water and directs the heated water into the brew chamber 1810 via a water inlet conduit 1863. In a representative embodiment, the brew chamber 1810 includes an agitator (not shown in
As described above, the brew chamber 1810 can be releasably coupled to the coffee chamber 1820, e.g., via a releasable connection to the coffee inlet conduit 1823. The coffee inlet conduit 1823 can have an inverted U-shaped design, as indicated in
In still a further embodiment, the lid can remain sealed to facilitate the brew chamber 1810 being pressurized (e.g., in a manner generally similar to that described above with reference to
The filter device 1830 within the brew chamber 1810 can include a filter platform or support 1831 releasably sealed to the sides of the brew chamber 1810 via an O-ring 1833. The filter platform 1831 can releasably support and/or carry a filter element 1832. The filter platform 1831 can be formed from stainless steel, PTFE, and/or another suitable food grade material. The filter element 1832 can include paper, metal, plastic, cloth, glass, and/or other suitable materials configured for single use or multiple uses. In any of these embodiments, coffee grounds 1850 are placed on or in the filter element 1832 during operation, before or after the brew chamber 1810 is coupled to the coffee chamber 1820, depending upon the particular embodiment. Hot water introduced into the brew chamber 1810 forms brewed coffee 1864. Once the brewing process is complete, the vacuum applied by the vacuum source 1801 (
In a particular embodiment, a generally conical, flat-bottomed paper or metal filter can be placed on top of the upper portion 2434a for support. In another embodiment, the filter platform 2431 can support a flat filter element. For example,
In the embodiments shown in
In a particular embodiment described above with reference to
In further embodiments, the brew chamber can be attached via motion in directions other than generally horizontal. For example, referring now to
In another embodiment shown in
One advantage of brew chambers having the coffee outlet port toward the top of the brew chamber is that the likelihood for hot brewed coffee to spill from the brew chamber if the brew chamber is inadvertently removed before being drained, is significantly reduced. Accordingly, if the brew chamber includes a coffee outlet port toward the bottom of the brew chamber, as described above with reference to
In any of the foregoing embodiments, the brew chambers can include quick-release, fluid-tight connections between the brew chamber and the rest of the brewing system. One advantage of this feature is that it allows the brew chambers to be quickly and easily detached so as to remove spent grounds, and then quickly and easily reattached with fresh grounds onboard. Another advantage is that it allows the brew chamber to be easily removed for periodic cleaning.
Still another advantage of at least some of the foregoing embodiments is that the entire volume of hot brewing water can remain in contact with the coffee grinds for a significantly longer period of time than is possible with drip brewers, which drip coffee extracted at varying concentrations throughout the brew process into a coffee holding vessel, such as a carafe. This feature, alone or in combination with agitating the coffee and grounds while in the brew chamber, can increase the uniformity of the extraction, which is commercially desirable. In addition, the force of the vacuum can quickly remove the entire volume of brewed coffee from the brew chamber once the desired extraction point has been achieved. Accordingly, this provides the operator with the ability to control the brew time with a higher degree of specificity than drip brewers, while also ensuring that coffee grinds are not exposed to different water levels for long periods, which would result in a non-uniform extraction.
From the foregoing, it will be appreciated that specific embodiments of the technology have been described herein for purposes of illustration, but that various modifications may be made without deviating from the technology. For example, the pressurized brew chamber described above with reference to
In a particular embodiment, an operator (or automated controller) adds an initial volume of water to grinds, then quickly extracts and discards it, then performs multiple subsequent extractions on the already-wet grinds, and combines two or more of the subsequent extractions. Accordingly, only some of the extractions are combined, and the grinds are not necessarily dry for the first of the combined extractions. This process can be desirable, for example, for removing caffeine prior to performing/combining extractions that will be consumed. In particular, the caffeine typically extracts first, so discarding a quick initial extraction can remove some or all of the caffeine when desired.
The grinds can also have other dimensions in other embodiments. For example, in at least some embodiments for which the system produces brewed coffee via multiple extractions, the grind diameter can be larger than 600 μ. In particular such embodiments, the grind diameter can range up to about 1000 μ.
Certain aspects of the technology described in the context of the particular embodiments may be combined or eliminated in other embodiments. For example, the agitation device described above can be eliminated in particular embodiments. In some embodiments, the aspects of the brewing processes and systems described above in the context of an automated or partially automated arrangement can be conducted in a manual arrangement, and vice versa. A particular embodiment of the foregoing devices that includes accelerated extraction provided by a vacuum device may be used to brew tea (via multiple extractions) as well as (or instead of) coffee. Further, while advantages associated with certain embodiments of the technology have been described in the context of those embodiments, other embodiments may also exhibit such advantages, and not all embodiments need necessarily exhibit such advantages to fall within the scope of the present technology. Accordingly, the present disclosure and associated technology can encompass other embodiments not expressly shown or described herein. The following examples provide further representative embodiments of the presently disclosed technology.
To the extent any materials incorporated by reference herein conflict with the present disclosure, the present disclosure controls.
1. A method for brewing coffee, comprising:
2. The method of example 1 wherein brewing the coffee includes brewing the coffee at atmospheric pressure.
3. The method of example 1 wherein the coffee remains in the brew chamber for a period of from 5 seconds to 5 minutes before being extracted from the brew chamber.
4. The method of example 1, further comprising drawing a vacuum on the coffee chamber to produce the pressure differential.
5. The method of example 4 wherein the pressure differential has a value of from 60 torr to about 759.999999999 torr.
6. The method of example 4 wherein the pressure differential has a value of about 585 torr.
7. The method of example 1, further comprising applying pressure to the brew chamber to produce the pressure differential.
8. The method of example 7 wherein the pressure differential has a value of at least one atmosphere.
9. The method of example 1, further comprising agitating the heated water and the ground coffee while the heated water is in the brew chamber.
10. The method of example 1 wherein placing ground coffee includes placing the ground coffee to have an average post-brew depth of less than 0.7 inches.
11. The method of example 1 wherein placing ground coffee includes placing the ground coffee to have an average post-brew depth of about 0.4 inches.
12. The method of example 1 wherein the operations of placing ground coffee, directing the heated water, and extracting the coffee are directed by an automated controller.
13. The method of example 1 wherein at least one of the operations of placing ground coffee, directing the heated water, and extracting the coffee is directed by an automated controller.
14. The method of example 1 wherein at least one of the operations of placing ground coffee, directing the heated water, and extracting the coffee is performed manually.
15. The method of example 1 wherein a volumetric capacity of the coffee chamber is from 1 to 12 liters.
16. The method of example 1 wherein extracting the coffee includes extracting the coffee with a period of from about 5 seconds to about 60 seconds.
17. The method of example 1 wherein the heated water is a first volume of heated water, and wherein the coffee is a first volume of coffee, and wherein the pressure differential is a first pressure differential, and wherein the method further comprises:
18. The method of example 17, further comprising:
19. A method for brewing coffee, comprising:
20. The method of example 19 wherein at least one of the first and second pressure differentials has a value of about 585 torr.
21. The method of example 19, further comprising, while the first volume of heated water is in the brew chamber, agitating the first volume of heated water and the ground coffee with a stream of gas introduced into the brew chamber.
22. A coffee brewing system, comprising:
23. The system of example 22 wherein the pressure differential device includes a vacuum source coupled to the coffee chamber.
24. The system of example 22 wherein the vacuum source is configured to draw a vacuum less than atmospheric pressure in a range of from about 20 torr to about 759.999999999 torr, absolute.
25. The system of example 22 wherein the pressure differential device includes a pressure source coupled to the brew chamber.
26. The system of example 22 wherein the pressure source is configured to produce a pressure of up to 10 atmospheres at the brew chamber.
27. The system of example 22, further comprising a controller programmed with instructions that, when executed, activate the pressure differential device.
28. The system of example 27 wherein the instructions, when executed: direct a first volume of hot water into the brew chamber;
29. The system of example 27 wherein the instructions, when executed:
30. The system of example 29 wherein the instructions, when executed, activate the pressure differential device for a period of from 5 seconds to 60 seconds to direct coffee, formed from the volume of water, into the coffee chamber.
31. The system of example 22 wherein the filter device includes a re-useable support element and a disposable filter element.
32. The system of example 22 wherein the filter device includes a re-useable filter element.
33. The system of example 22, further comprising an agitation device coupled to the brew chamber to agitate coffee and hot water in the brew chamber.
34. The system of example 22 wherein the agitation device includes an aerator.
35. The system of example 22, further comprising a releasable clamp positioned to releasably secure the filter along the fluid flow path.
36. A coffee brewing system, comprising:
37. The system of example 36 wherein the instructions, when executed:
38. The system of example 36 wherein the coffee chamber has a maximum capacity of 12 liters.
39. The system of example 36 wherein the filter device includes a re-useable support element and a disposable filter element.
40. The system of example 36 wherein the vacuum source has a capacity of at least one CFM.
41. The system of example 40 wherein the vacuum source has a capacity of at least one CFM for at least 5 seconds.
The present application is a continuation of International Patent Application No. PCT/US16/12910, filed Jan. 11, 2016, which also claims priority to the following pending applications: U.S. patent application Ser. No. 14/594,970, filed Jan. 12, 2015; U.S. Provisional Patent Application No. 62/171,190, filed Jun. 4, 2015; and U.S. Provisional Patent Application No. 62/267,185, filed Dec. 14, 2015, each of which is incorporated herein by reference.
| Number | Date | Country | |
|---|---|---|---|
| 62171190 | Jun 2015 | US | |
| 62267185 | Dec 2015 | US |
| Number | Date | Country | |
|---|---|---|---|
| Parent | PCT/US16/12910 | Jan 2016 | US |
| Child | 15641086 | US |
