Abstract:
A microwavable package for roasting coffee beans in which the package is shaped to be relatively larger in two dimensions than in a third dimension so that it presents a generally flat appearance or configuration. The package comprises a paper outer layer and an inner layer that includes a microwave susceptor. On the interior of the package a filter is provided, and a vent permits communication between the interior and exterior. The outer layer may be variously, kraft paper, bond paper, or filter paper. The inner layer may comprise a printed dipole antenna or a thin film conductor. The vent may be at least one perforation through both the inner and outer layers or a series of perforations. In a preferred embodiment, the package includes supports for maintaining the package in a generally vertical orientation when it is placed in a microwave to roast the coffee beans contained therein.

Description:
CROSS REFERENCE TO RELATED APPLICATION 
     This application claims the benefit of Provisional Application Serial No. 60/136,826, filed Jun. 1, 1999. 
    
    
     BACKGROUND OF THE INVENTION 
     The present invention relates to a coffee roasting apparatus and, more specifically, to an apparatus for roasting green coffee beans in a microwave oven. 
     Coffee is the world&#39;s most popular beverage after water, with an estimated 400 billion or more cups consumed annually. According to popular legend, coffee was first discovered in northern Africa by a goat herder who observed his goats acting unusually frisky after eating the berries from a particular type bush. The goat herder tried eating the berries himself and discovered that they gave him renewed energy. 
     Monks, after hearing about these berries, dried them so that they could be transported to distant monasteries. The berries were reconstituted in water, the fruit eaten, and the liquid drank to provide heightened alertness for prayer time. Coffee eventually traveled to Turkey, where beans were first roasted, crushed, and boiled in water to create the first version of the beverage enjoyed by so many today. 
     Today, specialty coffees are typically roasted in small batches at 400° in either a drum-type roaster, in which the coffee beans are tumbled in a heated rotary drum, or a hot air roaster, in which coffee beans tumble on a current of hot air. During roasting, sugar and other carbohydrates within the bean become caramelized, which gives coffee its flavor and aroma. 
     Many misconceptions exist regarding the optimum time after roasting to enjoy coffee. Generally, coffee is best if used within a day or two after roasting. In contrast, green coffee beans are good for years if stored in a cool, dry environment. Unfortunately, the coffee that most coffee drinkers consume was roasted long before it was brewed. Even afficionados of coffee are not likely to regularly experience their beverage of choice at its peak of perfection. 
     To alleviate this problem, a number of consumer or home-use coffee roasting devices have been developed. Typically, these require at least one additional piece of equipment, which must be stored in the already crowded kitchen of the coffee drinker, who is already hard put to find space to store his grinder, press, espresso machine, and other assorted paraphernalia needed for enjoyment of his beverage of choice. 
     Accordingly, it is the object of the present invention to take advantage of the long shelf life of green coffee beans and better flavor by using the coffee beans shortly after roasting by providing for home roasting of coffee beans. 
     It is a further object of the present invention to provide a disposable device for roasting an amount of coffee to be consumed by an individual user within a day or two. 
     More specifically, it is an object of the present invention to provide such a roasting apparatus that roasts the coffee beans by use of microwave energy. 
     SUMMARY OF THE INVENTION 
     These objects, as well as others that will become apparent upon reference to the following detailed description and accompanying drawings, are accomplished by a microwavable package for roasting coffee beans in which the package is shaped to be relatively larger in two dimensions than in a third dimension so that it presents a generally flat appearance or configuration. The package comprises a paper outer layer and an inner layer that includes a microwave susceptor. On the interior of the package a filter is provided, and a vent permits communication between the interior and exterior. The outer layer may be variously, kraft paper, bond paper, or filter paper. The inner layer may comprise a printed dipole antenna or a thin film conductor. The vent may be at least one perforation through both the inner and outer layers or a series of perforations. The package may also be provided with a see-through window for viewing the coffee beans before the package is opened to determine the degree to which the beans have been roasted. In a preferred embodiment, the package includes supports for maintaining the package in a generally vertical orientation when it is placed in a microwave to roast the coffee beans contained therein. 
    
    
     BRIEF DESCRIPTION OF THE FIGURES OF THE DRAWING 
     FIG. 1 is a perspective view of a first embodiment of a microwavable coffee roasting package according to the present invention showing the package disposed in a substantially vertical orientation. 
     FIG. 2 is a plan view of the package of FIG. 1 with the package open and prior to final assembly in order to show detail. 
     FIG. 3 is a plan view of the package of FIG.  1 . 
     FIG. 4 is a top view of the package of FIG.  1 . 
     FIG. 5 is a cross-sectional view of the package of FIG. 1, taken along line  5 — 5  of FIG.  1 . 
     FIG. 6 is a top view of an alternate method of folding the package of FIG. 1 prior to placement in a microwave oven. 
     FIG. 7 is a plan view of an alternate embodiment of a microwavable coffee roasting package according to the present invention. 
     FIG. 8 is a cross-sectional view of the microwavable coffee roasting package of FIG. 7, taken along line  8 — 8  of FIG.  7 . 
     FIG. 9 is a plan view of the inner layer of the microwavable coffee roasting package of FIGS. 7 and 8. 
     FIG. 10 is a plan view of a further embodiment of a microwavable coffee roasting package according to the present invention in which the package is reusable. 
     FIG. 11 is a cross-section of the microwavable coffee roasting package of FIG. 10, taken along lines  11 — 11  of FIGS.  10 . 
    
    
     DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS 
     In accordance with the invention, a microwavable coffee roasting package is provided that comprises a paper envelope, which may be either coated or non-coated, with a microwave heating film on the inside of the areas where the green coffee beans will be located when the package is placed inside the microwave oven for roasting. 
     The microwave susceptor comprises a microwave heating film, such as a printed dipole antenna to receive the microwave energy and convert it to heat. The susceptor may also comprise a thin film conductor that operates in the same manner. Any susceptor may be used so long as it is an FDA approved material for use in contact with food. The microwave susceptor may also be printed directly on the package stock. 
     The package also contains cotton paper in woven or non-woven forms (or other suitable filter materials) along the one edge to act as a smoke filter and for holding the hulls or skins that leave the coffee beans while roasting. The package includes supports that help keep the package properly oriented in the microwave oven during the roasting of the coffee beans. 
     The orientation of the package for roasting is preferably substantially vertical in order to minimize hot spots. This is achieved by configuring the package to have essentially a single layer of coffee beans, which allows for even heating from the microwave heating material. The package may be horizontally oriented, but this may provide for less consistent results. A small gap between the green coffee beans and the filter material allows for the expansion of the beans that occurs due to roasting. The package also has one or more vent holes to allow the steam and smoke generated by roasting to escape. 
     Turning now to the figures of the drawing, there is seen in FIG. 1 a perspective view of a microwavable coffee roasting package, generally designated  10 , according to the present invention. As can be seen in FIG. 1, the package  10  has a generally thin, vertical orientation and includes two supports  12  at either end that serve to maintain the package  10  in its vertical orientation. 
     In practice, the package  10  is preferably made of laminated paper and folded to the configuration shown in FIG.  1 . With reference to FIG. 2, there is seen a plan view of the package prior to folding and receipt of the green coffee beans that are to be contained therein. The package includes an outer sheet or layer  14  of a neutral pH, zero acid paper such as kraft paper, bond paper or filter paper. The package has an inner layer adhered to the outer layer  14  including a microwave heating film  16 . The film  16  is shown applied to the outer layer  14  in two discreet areas near the opposite edges of the outer layer  14 . The microwave susceptor  16  is applied to the outer layer so that, when the package  10  is filled with the desired amount of coffee beans, the beans are essentially sandwiched between the microwave susceptor  16 . The microwave heating film  16  may be directly applied to the outer layer  14 , or may be formed on a separate layer that is then laminated or otherwise secured to the outer layer  14 . For example, the microwave susceptor  16  may be a metallic ink printed onto a plastic film, which is then laminated to the outer layer. 
     In the center of the combined inner layer/outer layer is a vent hole  18 . A strip of filter material  20 , preferably made of cotton, extends down the center of the inner/outer layer laminate and covers the vent hole. The package is then folded about the X axis so that the microwave heating films are in face-to-face relationship, and the opposed edges are glued together, leaving the third side unglued so that the package can be filled with green coffee beans  22 . After the package  10  is filled with a single layer of green coffee beans  22 , the third edge is glued to complete the package. A cross-section of the package is shown in FIG. 5, including the green coffee beans  22  which are to be contained therein. 
     With reference to FIG. 3, a completed package is seen. When properly oriented in the microwave oven for roasting, the vent  18  is at the top of the package (as seen in both FIGS.  1  and  3 ). As best seen in FIG. 3, the support portions  12  of the package may be trimmed at a slight angle  24  so that when the supports  12  are folded as shown in FIG. 1, the package  10  will tilt slightly towards the direction of the supports  12 . This moves the center of gravity of the package more towards the center of the supports, thus creating a more stable package when in its vertical position. 
     At the user&#39;s option, the supports  12  do not need to be used. Alternatively, the package  10  can be folded in half again to form the package  10  seen in top view in FIG.  6 . This creates a larger base so that a more stable vertical orientation of the package is also attained. As is apparent, the package  10  could be folded to form an angle of less than 180° between the two halves and also provide for vertical support. 
     In the preferred embodiment, the package  10  may be provided with a window  26  in order to permit viewing of the roasted coffee beans  22  prior to opening the package in order to determine the degree to which the beans have been roasted. With reference to FIGS. 1 and 2, the window  26  is formed by a cut-out in the outer layer  14  in the upper portion of the package  10  between the microwave susceptor  16  and the filter  20 , with the cut-out covered by a transparent film, preferably made of plastic. The film may be of the same type on which the microwave susceptor is printed. 
     When the package  10  is filled with green coffee beans  22  and oriented vertically (as seen in FIGS.  1  and  5 ), the window  26  is above the level of the beans in the package. Thus the beans  22  can only be viewed through the window  26  when the package is inverted. When the package is inverted to view the roasted beans, the position of the beans is shifted so that if further roasting of the beans is indicated, the beans will not be returned to their original position when the package is returned to its upright roasting position. This helps to insure more even roasting of the coffee beans. 
     With reference to FIGS. 7-9, there is seen an alternate embodiment of the invention in which the inner layer and outer layer are made separately and are formed to create a more box-like package. In FIGS. 7-9, like reference numerals are used to refer to elements corresponding to elements illustrated in FIGS. 1-6. In contrast to the embodiment of FIGS. 1-6, the embodiment of FIGS. 7-9 includes a series of perforations for the vent. On the inner layer, the perforations are extended only about the periphery of the inner package. A sheet of cotton fiber or filter paper is preferably secured to the inside of the outer layer to the perforated area. As can be seen in FIG. 8, the supports  12  could also be used to support the package off the floor of the microwave, with the package oriented in a generally horizontal rather than vertical direction. 
     In a further aspect of the invention, a reusable microwavable coffee roaster  30  is seen in FIGS. 10 and 11. The device  30  includes a lid  32  and base  34  joined together by a hinge  36 . The base  34  of the roaster  30  has an insert  38  of material such as iron oxide that becomes hot when hit with microwaves. The lid  32  of the device also has an insert  40  of the same or similar microwave susceptor material. Insert  40 , however, has multiple holes that serve as vents. The lid  32  is also perforated with multiple holes. The insert  40  also serves to retain the filter material  42 , which can be, but is not limited to, cotton. The lid  32  and base  34  are joined at one end by a molded hinge  36  and at the opposite side by a molded latch  44 . The base also has a plurality of legs  46  (at least three) to raise the unit off the bottom of the microwave oven floor. 
     In use, the device  30  is opened, and a measured amount of green coffee beans are placed in the lower half, with the recess serving to measure the correct amount of beans. The lid  32  is closed, and the roaster  30  is placed inside a microwave oven and hit by microwaves. The holes in the upper heating element  40  allow the smoke and water vapor from the roasting beans to go through the filter and the holes in the lid  32 . The resultant direct and convection heat serves to roast the green coffee beans. After roasting is completed, the device  30  is removed from the microwave and the beans removed. The roasted beans can now be ground or stored. 
     Accordingly, a coffee roasting package and a method of roasting green coffee beans using a home microwave oven has been provided. The combination of direct heating of the green coffee beans by the microwaves and the use of materials that convert microwave energy into heat result in the selective and controllable roasting of the coffee beans. The design of the packaging and the orientation of the package in the microwave oven achieve this. The device may be constructed as a disposable pre-loaded package or as a reusable consumer-filled device. While the invention has been described in terms of certain preferred embodiments, there is no intent to limit it to the same. Instead, the invention is defined by the scope of the appended claims.