Abstract:
A method and apparatus for pan roasting a mass of green coffee beans at rest by heat conduction from the pan bottom to the beans mass. A glass cover and smoke filter closes the roasting chamber. A radial blower operates at slow speed to draw ambient air and vacate smoke from the chamber to permit visual monitoring of roasting beans. Periodically, the fan can operate a high speed for a short time to mix or swirl the bean mass without substantial cooling them. The blower can sequence through high and low speed cycles until roasting completes and heating ceases. A high speed cool down phase removes remaining chaff, smoke, and quick cools the beans to preserve freshness. Electric power drives the blower and resistant heating element. The system enables the operator to use appearance, sound, smell, and time to determine roasting completeness.

Description:
RELATED APPLICATIONS 
     This is a Continuation-in-Part of U.S. patent application Ser. No. 11/185,541 filed Jul. 19, 2005 now abandoned which is a Continuation-in-Part of U.S. patent application Ser. No. 10/043,873 filed Jan. 10, 2002 now U.S. Pat. No. 6,942,887, which claims priority of Provisional Application Ser. No. 60/261,124 filed Jan. 12, 2001. This is also a Continuation-in-Part of U.S. patent application Ser. No. 11/105,321 filed Apr. 13, 2005 now abandoned, which is a continuation in part of Ser. No. 11/085,868 filed Mar. 23, 2005 now abandoned, which is a Continuation-in-Part of U.S. patent application Ser. No. 11/059,291 now abandoned, filed Feb. 15, 2005, which is a continuation in part of Ser. No. 10/043,873 filed Jan. 10, 2002 now U.S. Pat. No. 6,942,887 which claims priority of Provisional Application Ser. No. 60/261,124 filed Jan. 12, 2001. Applicant claims priority of all these applications. 
    
    
     BACKGROUND 
     Green unroasted coffee beans remain useful for extensive time periods. When roasted, unground coffee beans begin to lose flavor in a day and shall have lost almost all flavor in a week. Ground coffee deteriorates even faster. 
     As the people become more sophisticated about food and coffee, the consumer market demand grows for better quality coffee beverages. Specialized coffee shops have arisen to meet this demand. However, many of these shops provide no in-store roasting. Roasted beans are shipped from a central location to shops all over the country. The coffee served at these shops has spent the prime of its life in transit. The pre-roasted whole-bean coffee one buys in supermarkets is even older. 
     Freshly roasted and ground coffee is vastly superior compared with these pre-roasted products. Various systems are known that attempt to roast green coffee beans and otherwise process them shortly before grinding and using them to make fresh coffee. See for example, U.S. Pat. Nos. 3,964,175, 4,326,114, and 6,123,971. These disclosures recognize the value of rapid cool down of roasted beans but suffer from various process steps that prevent production of a good quality product. For example, these systems fail to enable the operator to visually inspect the roasting bean color to control various process steps that can produce a better quality final roasted bean. 
     Various characteristics of the roasting beans can be used to indicate or measure quality during the roasting and cooling cycle, such as the color of the roasting beans, smell of the rising aroma, crackling sounds of the beans, and the length of time, roasting energy consumed, and bean temperature. Technical problems must be solved to effectively use one or more of these characteristics. For example, the generally known fluidized bed coffee bean roaster uses streams of radiantly heated hot air to carry, circulate, and roast the beans. However, the operator of these systems cannot observe the individual bean color but only a swirling mass during the roasting. Operation of other household units of the drum type cannot visually inspect the beans while roasting. All of these units do not attempt to minimize the smoke produced such that they need to be vented or used outside to avoid creating a polluted environment. Similarly many or these units fail to collect chaff and spread chaff over an already polluted environment. Most of the household fluidized bed units roast only 2 to 3 oz. (¼ to ½ cup) of green beans and have little tolerance for different amounts. These limitations are due to design but are mainly due to the principles of operation and power use of the fluidized bed devices. 
     SUMMARY OF EXEMPLARY EMBODIMENTS OF THE PRESENT INVENTION 
     The roasters according to the principles of the present invention provide substantial benefits over previously known systems and enable the operator to use one or a combination of up to all of the above mentioned characteristics of roasting coffee beans while avoiding or solving the above mentioned technical problems. 
     One exemplary embodiment according to this invention includes a small batch coffee roaster for the home and restaurant markets to produce automatically a repeatable roast coffee bean in the ½-4 green bean cup range (3 oz. 1⅓ lbs.) which will give optimal control of roasting bean color which is the main determinant of doneness, fast cooling of the beans once roasting is complete, collection of chaff, and elimination of most smoke and odor. This embodiment enables the operator to smell a small amount of smoke and to listen for crackling sounds as a further or alternate indication of doneness. 
     Another exemplary embodiment according to the principles of the present invention includes an alternate more effective chaff catching, smoke filtering, and processing design and technique. This embodiment lends itself well to not only ½-4 cups of green beans including, if desired, one or more layers of beans for home or commercial use. 
     All embodiments are capable of providing a roasting method that preferably substantially roasts the beans by conduction heating when they are at the rest so that color can be observed through a transparent cover. As roasting heat is applied by conduction, a blower exhausts the air and steam through a filter that traps most smoke particles and circulates air within the pan at an air speed that does not disturb the resting, roasting beans. Preferably, the blower moves the air at high speed to agitate, stir, or circulate the beans for a short time and then cuts-off or gradually reduces to low speed to allow the beans to come to rest again for at-rest roasting. Because the blower operates at increased speed for one or more short time periods, the beans retain most of their residual heat and are not significantly cooled while they are stirred or swirled about the roasting chamber. The roasting continues with the beans retaining most of their residual heat when the blower speed is reduced and the beans come to rest. Preferably, the heater continues to supply heat energy through the at-rest roasting and the stirring cycles. As described below, these cycles repeat as necessary until the operator determines that the beans are almost fully roasted. Due to exothermic processes within the beans they continue to heat up when external heat is removed so they are subject to external cooling slightly before the final roast color is seen. Although some chaff will be transported by air currents during the slow speed phase, most chaff will be collected during the high blower speed phase. The subject systems can roast the beans by a process that separates the roasting and cooling phases even though the roasting beans are air stirred because the residual heat of each bean is not removed until the final rapid cool down phase, more fully described below. Systems according to the principles of the present invention lend themselves well to use electricity as the only needed source of energy for all system functions. 
     According to another embodiment, a control with a panel sets parameters changeable by a user. 
    
    
     
       BRIEF DESCRIPTION OF DRAWINGS 
       Other and further benefits and advantages of systems and methods according to the principles of the present invention will become apparent with the following detailed description of exemplary embodiments when taken in view of the appended drawings, in which: 
         FIG. 1  is a pictorial view of a vertical cross section through the center of one exemplary embodiment according to the principles of the present invention. 
         FIG. 2  is similar to  FIG. 1  showing an alternate embodiment according to the principles of the present invention. 
         FIG. 3  is similar to  FIG. 2  showing a single layer of beans therein and the general airflow paths generated by the blower at low speed. 
         FIG. 4  is similar to  FIG. 3  depicting the beans and airflow and chaff with the blower at high speed. 
         FIG. 5  is similar to  FIG. 3  depicting a multi-layer mass of green beans in the pan. 
         FIG. 6  is similar to  FIG. 5  depicting the beans during high blower speed. 
         FIG. 7  is a section view of the pan and beans taken along line  7 - 7  of  FIG. 6 . 
         FIG. 8  is similar to  FIG. 2  for a further alternate embodiment and showing general blown air flow thereof. 
         FIG. 9  is a sectional view of a portion of a portion of another embodiment of the invention. 
         FIG. 10  is a graph illustrating the operation of an embodiment of the invention. 
         FIG. 11  is a block diagram of a control embodying the invention. 
         FIG. 12  is a block diagram of a panel illustrating an embodiment of the invention. 
         FIG. 13  illustrates yet another embodiment of the invention. 
     
    
    
     DETAILED DESCRIPTION OF EXEMPLARY EMBODIMENTS 
     In  FIG. 1 , a coffee bean roasting system  10  according to the principles of the present invention includes a metal skillet-like pan  12  having a suitable shape and size to accommodate one or more layers of green coffee beans and function as a roasting chamber therefor. In this example pan  12  is circular but could be octagonal, hexagonal, or other suitable shape with a bottom that is generally flat or one which could be slightly sloping toward the center, if desired. Legs  42  support the pan and other assemblies above a counter top or other suitable surface. The pan bottom defines a center opening  14  to enable airflow and accommodate the shaft of motor  24  that drives a radial blower  26  as more fully described below. Brackets or other suitable members (not shown) mount AC motor  24  to the pan such that blower  26  rotates to cause air to draw and to circulate within the roasting chamber. A mesh screen about the blower removes ambient particles and in particular prevents the beans from interfering with the blower. 
     Pan  12  cooperates with removable transparent cover  14  to close the roasting chamber. Cover  14  is flat or dome shaped and is preferably made of glass although other materials are possible. Cover  14  defines an opening  15  generally at the top thereof. A filter and chaff catcher assembly  16  mounts to top  14  about opening  15 . Assembly includes a chaff catching cup  18  the lower portion of which is solid and the upper portion of which is defined by screen  19  with openings of about ⅛ inch that permits the passage of chaff but denies the passage of coffee beans. A solid baffle  21  forces the exhausting gasses downward below the baffle, small mesh screen  9 , and an upper screen portion  21  that permits the gasses to pass. A solid top or cover  23  prevents gasses from exhausting out the top of assembly  16 . While filter medium  22  serves to filter out smoke particles and, in this embodiment, odor filter  25  filters most but not all odors so that the operator can smell the aroma of the roasting beans. Filter  25  could be a carbon filter. According to an embodiment, filter medium  22  is a 1.0 to 0.1 micron HEPA or ULPA filter for smoke removal generally available in the industry. The filter opening size would depend upon the size and extent of the smoke particles the manufacturer desires to emit into the ambient. The assembly can be mounted to the glass top or dome by various bonding materials such as epoxies or adhesives and screw type devices to enable removal of chaff and catching cup and occasional filter replacement. It is preferred that the continuous edge of top  14  include a suitable sealing material  31  such as such as food-grade sealants to substantially prevent air circulating within the chamber from escaping between the pan and the dome. 
     System  10  further includes a controller  30  with a panel that includes certain push buttons or dials  32  that enable the operator to set automatic heat energy and blower applications or manually set or override such settings. Power cord  34  provides standard house 110 volt house power or 220 volt power as desired. Power cord  36  provides power and speed control to the motor  24  and power cord  38  provides heat energy to resistive heater  40 , which may be in the form of a coil or cal rod, that in turn heats the bottom of pan  12 . 
     In one method example, the unit of  FIG. 1  was operated in the manual mode. Approximately one cup of green beans was spread evenly on the bottom of the 12-inch diameter pan  12  with four-inch high sidewalls. Opening  14  was 3 inches in diameter as was the opening in the top of glass dome  14 . The blower  26  was a LAU radial blower #C2895767, 3 and 13/16 th  inches by 1 and 1/32 inches high radial blower with 30 back-curved blades, CCW Rotation in plan view. 
     The glass lid  14  with filtration assembly  16  attached was placed on the pan to close the chamber. 
     The heating rod  40  was energized for 10-12 minutes at 1400 Watts. 
     The stationary layer of roasting beans was visible through the glass lid and the sounds (crackling) of roasting were clearly heard. The aroma of roasting coffee beans was discernable without excessive smoke filling the room. 
     Once the required or sufficient degree of doneness was perceived by sight, smell, sound, and/or time, the heating unit was turned off and the cooling unit (the motor-blower  24 - 26 ) was turned on at about 6500 RPM. 
     Some smoke was visible on the outside of the filtration unit early in the cooling cycle. As the roasted beans were swirled around inside the roasting chamber during the cooling cycle, they were being cooled by the outside drawn and circulating air. As they swirled around, chaff was loosened and deposited into the chaff cup or catcher, and the pressure differential caused by the motor-blower unit caused the effluent to pass through the ⅛ th  inch grid around the baffle and out through the smoke and odor filters. 
     After about six to eight minutes of cooling cycle, the beans were cooled sufficiently to stop the roast and retain the previously observed doneness. Due to exothermic processes within the beans they continue to heat up when external heat is removed so they are subject to external cooling slightly before the final roast color is seen. The motor-blower unit was turned off. The glass lid was removed and the roasted beans emptied out and stored in sealed glass jars. Later, as needed, the stored beans were ground and processed into a fresh cup of coffee beverage. 
     In another method example, cover  14  is removed and a layer or more of green coffee beans is deposited on the floor of pan  12 . The operator selects the mode, e.g. “Manual”, and applies power to heating rod or element  40  that, in turn, heats by conduction the bottom of pan  12  and the resting beans. As the beans begin to roast the operator can inspect the bean color and listen to the roasting sounds as desired. In addition, the operator can turn the blower assembly on a relatively slow speed such as 1000 RPMs to force the smoke and steam out through the filter assembly to preserve bean visibility. The radial blower  26  draws outside air in and circulates the air generally as shown in dotted lines in  FIG. 1 . Because of the slow blower speed and the continued application of heating energy to element  40 , the beans remain at rest and continue to absorb roasting energy. During this phase, the blower draws fresh air into the chamber and forces air with smoke and steam out of the chamber in the path shown by the dotted lines. Some chaff that separates from the roasting beans may be carried out with the exhausting air but when the chaff clears the bottom of the baffle  21  it remains at the bottom of the cup  18  due to its weight and inertia. The smoke and steam, however, continue upward and through the filters  22  and  25  and exit the system. 
     According to one embodiment, the arrangement is set so if the operator notes an excessive burning smell or excessive color change in one segment of the bean body, the operator can sequence the select key SE 1  and use the up key UK 1 . This applies more power to motor  24 , which increases the blower speed to cause the beans to fly outward and against the sides of pan  12  and against each other. Some beans would also circulate back toward the center of the pan in a swirling motion. In effect, the beans would be effectively stirred within the chamber. In one example, the high blower speed for a 12-inch pan is 6000 RPM. This stirring cycle should be short, e.g. about 10 to 20 seconds, so that the body of beans is not significantly cooled but instead retain most of their residual heat. Preferably, the power continues to be applied to the heater  40  so that the net cooling is reduced during this phase. Also, during this high-speed cycle, most of the chaff is carried up and out of the pan itself and deposited in cup  18 . This chaff removal and collection also aids the operator&#39;s visual inspection of the roasting beans when the beans come to rest. Once the beans are stirred, the operator can manually reduce the blower speed by pressing the appropriate button on controller  30 . Preferably, the controller reduces blower speed gradually so the beans distribute along the pan bottom evenly. This can be done manually by rheostat control or automatically by programmed IC chip in controller  30 . The beans will come to rest on the pan bottom where they will resume their roasting by way of the heat energy applied by conduction through pan bottom. Some of the beans may be piled up at the outer portions of pan  12 , but this will not affect the quality of the roasting method and over time, the vibrations or the system will cause those beans to migrate toward the center of the pan bottom. Also, since most beans have one flat side (the other is rounded), they tend to come to rest with flat side down for best conductive heat transfer with pan bottom. Ramping the speed up and down causes the blower to go briefly through its resonant speeds. The general vibrations and the vibrations produced as the blower goes through its resonant speeds as well as the changes in speed during ramping causes the mass of beans to spread fairly evenly over the circular pan. 
     The high and low speed cycles can be repeated as desired by the operator. In one example of the method, the low-speed cycles lasted two to three minutes and the high-speed cycles lasted about 20 seconds. Three to four cycles were needed for fully roasting the beans. 
     Once the beans were fully roasted, power to heater  40  was cut off and the blower set for high speed. This high-speed cycle is a rapid cool-down cycle not only to rapidly cool the beans to capture flavor but also to separate and carry off the remaining chaff from the stock of roasted beans. This cool-down cycle lasted about 6 minutes in this example. 
     An alternate system  50  according to the principles of the present invention is shown in  FIGS. 2 to 8  where common reference characters refer to similar elements to system  10 . System  50  includes metal pan  62  defining opening  14  in the pan bottom. In one example, the pan  62  was 12 inches in diameter with four-inch high sidewalls. The pan bottom can be high finish aluminum and thick enough to cooperate with rod  40  to provide even heating to the bean layer. 
     A cover assembly  52  functions to close the roasting chamber, collect floating chaff, and filter most smoke and steam from exiting gases and particles. Assembly  52  preferably includes a glass dome shaped cover  55  with handle  53  and smoke filter  66  that preferably extends completely around the periphery of the outer edge of cover  55 . Filter  66  can be secured to cover  55  by seal  68  to form a single unit raised and lowered by handle  53 . In one example seal  68  extends along and is integral with the top of filter  66  and is shaped to releasably mate with the outer edge of glass cover  55 . A further seal  64  lines and is integral with the bottom of filter  66  and functions to releasably seal filter  66  of the cover assembly  52  to the top edge of pan  62  when assembly  52  is placed on the pan. Seals  64 ,  68  can comprise any suitable material such as food-grade sealants. Preferably, filter  66  and it seals  64 ,  68  can be selectively removed from cover  55  to permit cover and filter cleaning and chaff removal as desired. It has been determined that a filter selection that blocks all but 1.0 micron particles is suitable. However, a 0.1 micron filter is preferred to prevent too much smoke for inside use but allow some smoke to exit the system for operator indication of roasting completion by the smell parameter. Alternately, a carbon post-filter can be used in combination therewith. Crackling sounds can also emanate with such filters. Assembly  52  can further include a chaff screen  77  that can extend to the inner surface of dome  55 , as shown, or be spaced below it. Screen  77  has openings that approximate ⅛ th  inch to enable floating chaff to penetrate the screen but reject beans from such translating through. Any chaff that translates through screen  77  will be blocked from exiting the system by filter  66 . Instead, chaff will accumulate in space  78  on the top of floor  75 , where they can be discarded after the process is completed. A smaller opening, chaff-blocking screen (not shown) can be placed along the inside surfaces of filter  66  to prevent chaff from jamming the filter ports. 
     It will be understood that seals  64 ,  68 , filter  66  and screen  74  are shown extending completely about the system periphery as represented by the dashed lines. However, it would be within the scope of the invention for those elements to extend substantially about the periphery so long as they function to remove substantial smoke to permit inside, non-vented use and allow some odor to emanate to aid the operator. By extending completely about the periphery, assembly  52  maximizes the exhaust area, the area to filter the smoke, and the space to catch the chaff. An advantage of the wide peripheral filter is that it does not clog as easily as smaller filters. 
     This arrangement also enables the same size filters to be stacked one atop the other (not shown) to increase these capacities even further for restaurant applications or applications where a lot of beans are roasted to a dark color, resulting in a great deal of smoke. 
     Motor  24  and controller  30  can be mounted to the pan  62  or to the legs or to some frame member (not shown) as desired. Radial blower  70  draws air from outside the system and provides air circulation as further described below. Screen or mesh  72  is mounted on the floor of the pan  62  about blower  70  to prevent beans from engaging the rotating peripherally-distributed and radially-extending blower blades  73  of the blower. Only part of screen  72  is shown for simplicity. The screen  72  is in the form of an upside-down saucer having a flat top and a cylindrical wall about a vertical axis. The motor  24  is positioned so that the blower  70  with its blades  73  projects inside the heated space. The opening  14  is small enough so the pan  62  covers the blades  73  completely from underneath. This assures a static pressure difference between the space of the blower and the remainder of the chamber. It also produces a swirling movement of air that, depending on the speed, moves the beans circumferentially, and/or blows out the oils and steam and smoke. The motor  24  is outside the heated space and in the flow of the incoming cold air stream which keeps the motor cool. A flat baffle or disk, such as  82  of the embodiment of  FIG. 8 , can be added on top of the motor but below the bottom surface of the pan  62  to keep the motor even cooler and during the final cooling operation to draw cooling air in across the outside bottom surface of the pan, thereby decreasing the cooling cycle time. 
       FIG. 9  is a sectional view of an embodiment of the filter screen  77  showing filter screening in the form of a one piece assembly for use in any of the other embodiments. Here, a circular bottom end cap BE 1 , secured peripherally around a vertical cylindrical edge of the pan  62 , and a top end cap TE 1 , secured to a steel rim ST 1  of the glass top  55 , hold the cylindrical ULPA filter  22  between them. A cylindrical outer chaff screen OC 1  inside the ULPA filter  22  exhibits 1/16″ openings. A cylindrical inner chaff screen IC 1  with an L-shaped cross-section inside the outer chaff screen OC 1  present ⅛″ openings. The cylindrical inner chaff screen OC 1  prevents larger debris such as the beans from hitting the ULPA filter  22  and the cylindrical outer chaff screen IC 1  traps chaff TP 1  between the filters OC 1  and IC 1 . According to an embodiment the filters OC 1 , IC 1 , caps BE 1  and TE 1 , as well as the ULPA filter  22  form a single assembly. 
     ULPA filters are used in high grade medical filters. They filter out 0.1 microns and above—just like this filter. This includes pollen, dust mites, mold spores, and most cigar/cigarette smoke. If run in “fan only” mode (heater off), this roaster will take ambient air and remove the same contaminants as a medical ULPA filter, and deliver the cleaned air back to the environment. 
     In operation, one or more layers of green coffee beans are spread on the floor of pan  62 .  FIG. 10  illustrates the operation of the blower  70  and the heating element  40 .  FIG. 10  illustrates the operation in terms of speed with respect to time. Here, the process begins with vent and proceeds thereafter with stir, vent, stir, vent, etc. Heating occurs during both the stir and the vent periods. The vent operation removes the steam and smoke that may accumulate. 
     As shown in  FIG. 10 , power is applied to heating element  40  to heat the bottom of pan  62 . The pan bottom, in turn, heats the resting beans by conduction. Simultaneously at the start of the heat application or shortly thereafter, blower  70  is activated at slow speed, e.g. 1000-1500 RPM, to remove smoke and steam. This is the first vent cycle shown in  FIG. 10 . Blower  70  draws outside air in through opening  14 , circulates it outward and circumferentially. See  FIG. 3 . This relatively slow-moving circulating air carries the smoke and steam in a swirling motion and upward and outward pattern, thence out through screen  74  and filter  66 . Note the beans continue to rest and roast for the heat energy applied by element  40  is sufficient to roast the beans regardless of the cooling effect applied by the slow moving air. In addition, the operator can easily visually and audibly monitor the roasting beans for color and crackling sounds because the smoke, steam, and chaff are carried away by the slow moving air, and the slow speed blower generates little noise. 
     The operator, upon judging that stirring the beans would be beneficial or necessary, can manually control motor  24  to cause blower  70  to rotate at high speed, e.g. 6500-7000 RPM for a short 10-20 seconds. This is the stir operation shown in  FIG. 10 . Blower  70  generates high-speed air drawing and circulation. This action causes the mass of beans to swirl toward the outside portions of the pan  62 . However, because blower  70  also applies a circumferential vector component to the blown air, the mass of beans also moves circumferentially about the pan  62 . See  FIGS. 4 and 6 . It is noted that the beans located more toward the pan center move circumferentially more rapidly than beans located more toward the pan outer walls. However the beans may move in many ways. Close to the blower the beans may move CCW—the same direction as the blower itself; towards the outside of the bean mass, the beans may move CW perhaps due to the induced vibrations in the pan (from the motor/blower) in addition there is a radial movement of beans-downwards on the outside of the mass and upward on the inside. It is thought (though we cannot see it) that the beans move radially inward on the bottom of the mass. One can see the radial movement outward on the mass top. These movements combine to give very complex but very effective stirring. 
     The main purpose of this swirling action is to stir the beans and to separate chaff and remove chaff and smoke and steam, not to cool the mass of beans because the roasting thereof has not completed. Accordingly, the high-speed blower cycle should be short and the power to element  40  should remain on during these high-speed cycles. During roasting, the beans become gradually lighter due to removal of moisture and coffee oils, and also increase in dimension (i.e. expand) and become less dense. With this method of mixing the lighter less-dense more-roasted beans migrate to the top or are thrown up higher than the denser less-roasted beans during mixing, vibrating and stirring. So the less-roasted beans should be closest to the heating surface once a mixing cycle is complete and the beans have redistributed and come to rest. 
     Air as a stirring medium gives us completely unbroken beans—a consistent problem with prior devices. The fan only stirring operation has a number of advantages. When a roast is complete there is still residual heat in the pan. If one is roasting repeated roasts of the same beans to the same doneness (as a coffee house or restaurant might choose) one would use the retained automatic parameters selected for the first roast. However one would use “fan only” operation with the heater off to bring the roaster back to the original ambient conditions before beginning subsequent roasts; otherewise the results would not be consistent. 
     Once the beans are sufficiently stirred, the operator or the system automatically, shifts the blower to slow speed to start the second vent cycle of  FIG. 10 , and the beans come to rest again on the pan bottom. Some beans will initially remain piled up along the sidewall. However, the natural vibration of the system tends to cause the beans to spread out somewhat toward the pan center. To better redistribute beans after stirring, it is preferred to gradually de-accelerate the blower so the centrifugal force is decreased and as the blower slows down beans are deposited in an ever-decreasing circle on the pan bottom. As the blower goes through its resonant speed on the way down, vibration causes the mass of beans to move towards the center from the outside. If desired, the pan bottom can have a slight central, conical slope from the outer edge. A 12-inch pan may have a 1 to 2 inch descent and a smooth surface inside the pan to distribute the beans across the surface more evenly. The slow vent cycles and high-speed stir cycles can be repeated as desired until the beans are fully roasted and show a desired color, sheen, sound, and/or odor. In one example, the slow speed cycles extended for 3-4 minutes and the high-speed cycles extended for about 20 seconds. The beans were fully roasted in 3-4 complete cycles. 
     Once fully roasted, it is preferred that the beans be quickly cooled to preserve flavor in the beans and preserve the condition (done-ness) or roast completion at which the roasting was stopped. System  50  applies rapid cool down by simply operating blower  70  at high speed and cutting power to rod  40 . As mentioned above, this action draws cool air into the systems, swirls the beans to cool them, and forces heated air out through the filtering system. In one example, the cool down cycle lasted 6-9 minutes. Cover assembly  52  was then removed and the cooled beans placed in jars for storage. These beans were later ground and used to make a fresh coffee beverage. 
     Although alternating low air speed phase and high air speed phase are mentioned above, it is within the principles of the present invention that other air off phases or intermediate air speed phases and transition phases can be employed with the present systems and methods as desired. 
     It should be understood that, as long as the amount, coffee type, and required roast result remain the same, parameters can be pre-programmed for the automatic mode of operating systems  10  and  50 . Results from these preprogrammed systems would be substantially uniform from roast-to-roast. Systems  10  and  50  are also relatively quiet permitting the operator to hear all crackling sounds. The beans roast while at rest so that the operator can see the color of individual beans see the slight movement of individual crackling beans, and hear the crackling. The present method also enables the beans to retain a significant amount of their natural oil while eliminating moisture, which produces a better-flavored product. A blower wheel with radial and/or curved blades creates a strong current at air to cool the beans, carry the chaff, and enough static pressure head to push air through a 0.1 micron filter. Also, it uniquely creates a swirling motion, (not just a radial motion) which rotates and turns over the entire bean mass, thereby cooling and/or mixing the beans very efficiently. With the present system  50 , the balance between blower, filter, motor, heater  40 , smoke, cooling are such that this process is balanced and can be based on a 20-amp 115 volts circuit, i.e. US standard house kitchen circuit power, if desired. The present invention also facilitates a scaled up system so that more coffee beans can be roasted in a given roast cycle. For example, a 24-inch diameter pan can be used with generally a 220-volt 20-amp circuit to roast about 7 pounds of green beans. Also, a drop or rise in line voltage will not significantly affect the roasting cycle because conduction heat transfer varies with temperature difference. For example, a ±10% line voltage variation results in a heat transfer variation, which is insignificant to the overall cycle when compared to the known systems of fluidized bed or drum type, which rely on radiant heat transfer. In the present invention, it is possible to roast 2 or more green pounds of beans in one operation. Of course the beans lose weight in the roasting process. 
       FIG. 11  illustrates an embodiment using a programmed IC chip CH 1  in controller  30  to effect operations such as the one shown in  FIG. 10 . Here, input lines from the panel PA 1  on the controller  30  enter instructions determined by the operator to the chip CH 1 , and output lines send operating and timing commands to the motor  24  that drives the blower  26  and the resistive heater  40 , the latter in the form of a coil or cal rod, that heats the bottom or pan  12 .  FIG. 12  illustrates an embodiment of a panel PA 1  on the controller  30  that permits an operator to enter the instructions to the chip CH 1 . The panel PA 1  includes an Up switch or key UK 1 , a Down switch or key DK 1 , a Start-Stop switch or key SK 1 , a Total Time switch or key TK 1 , an Auto/Manual switch or key AK 1 , and a Select switch or key SK 1 , collectively identified as switches SW 1  and respectively connected to input lines to the chip CH 1  for transmitting instructions to the chip. A Heat LED HL 1  responds to the chip CH 1  to light when the heater  40  is on, and a Cool LED CL 1  responds to the chip CH 1  when the motor  24  drives the blower  26  while the heater  40  is off. 
     In general an operator can use a preset automatic mode or can use a manual mode. The steps and timing used in the manual mode for one type and quantity of beans for a particular roast completion or “done-ness” can be memorized and used to control subsequent automatic operations on similar types and quantities of beans for that particular roast completion or “done-ness”. 
     In the manual mode of operation the operator starts the roast with the start/stop key SK 1  and observes the roasting process and decides visually whether the beans have reached the operator&#39;s desired “done-ness”. The operator then ends the process by hitting the start/stop key SK 1 . This sets the total time that the chip CH 1  memorizes. In the automatic mode, the operator hits the start/stop key SK 1  and the roast continues for a total time that the chip CH 1  has memorized from a preset time entered by the factory, has memorized from a preset time more recently entered by the operator, or has memorized from a more recent manual operation. 
     In addition, in either the manual or automatic mode, the operator can accept factory presets for a number of operating conditions, select the operating conditions, or accept previously selected conditions. Examples of such conditions are vent times, stir times, stir speeds, etc. According to an embodiment, certain conditions can be set as defaults to which the operator can return at any time. The conditions are entered to control various steps in the process. 
     During the roasting, the blower  26  alternately runs at a speed to vent the beans and to stir the beans while the beans are being heated. The panel PA 1  includes a display DI 1  responsive to the chip CH 1 , and actuated by successive operation of the select key SE 1 , to indicate values such as the vent speed of the blower  26 , vent time, and stir speed of the blower, and the stir time. LEDs collectively identified as LE 1 , and connected to lines in the chip CH 1 , light to indicate which value is being displayed in the display DI 1  in response to the select key SE 1 . Specifically, a stir speed LED SL 1  lights when the select key SE 1  causes the display DI 1  to indicate the stir speed, a stir time LED ST 1  lights when the select key SE 1  causes the display DI 1  to indicate the stir time, a vent speed LED VL 1  lights when the select key SE 1  causes the display DI 1  to indicate the vent speed, and a vent time LED VT 1  lights when the select key SE 1  causes the display DI 1  to indicate the vent time. 
     The switches SW 1  and LED indications are examples only and other embodiments may use other indications, switches, and displays. 
     In operation of the system including the chip CH 1 , one embodiment involves turning on a main power switch PS 1 , which causes the chip CH 1  in the controller  30  to make the system power up in the idle (off) condition. The chip CH 1  then keeps a heater relay of the heater  40  and speed control of the blower  26  off. Pressing the Auto/Manual switch or key AK 1  once selects the manual mode of operation and the chip turns the Manual LED ML 1  indicator ON. Pressing the Manual/Automatic Switch or key AK 1  again selects the automatic mode of operation. This turns the Auto LED AL 1  on. The display DI 1  then shows the total time that was previously set and a total time LED LE 1  lights. If total time was not set then the display indicates 00. 
     Pressing the Manual/Automatic Switch or key AK 1  again selects the fan-only mode of operation. In this mode the heater  40  is off and the cool LED CL 1  is on. The fan-only mode of operation cools off the pan for subsequent roasts. It also works as a medical air cleaner. Selecting the fan-only mode causes the display DI 1  to show FO. Pressing the Manual/Automatic Switch or key again selects the idle mode. This turns the manual and automatic LEDs OFF and the display off. The idle mode is a non-functional mode. In the idle mode the controller  30  does not cause the system to perform any function. 
     Pressing the Start/Stop Key SK 1  starts the manual or automatic cycle selected by the Auto/Manual key SK 1 . Pressing the Start/Stop Key SK 1  again in the selected Auto/Manual mode stops a running automatic or manual cycle. Pressing the Start/Stop Key SK 1  starts and stops a fan only cycle. When a manual cycle is running, pressing the Start-Stop switch SK 1  causes the cool cycle to begin and the Cool LED CL 1  to light. 
     Pressing the Total Time key TK 1  enables the Automatic Total Time Set mode. Pressing the Total Time key TK 1  again cancels the Automatic Total Time Set mode. Total Time settings vary from 0 to 50 minutes in one-minute increments. Pressing the Start/Stop key SK 1  in the Automatic Mode causes the chip CH 1  to make the Total Time revert back to the preset value. The Total Time Key SK 1  remains disabled until the Automatic mode is chosen. 50 minutes is the maximum preset time. After that the device is turned off for safety purposes. 
     Pressing the Select key SE 1  sequentially generates different functions. A first Select key SE 1  press enables the vent (or stage one) time set mode and the vent time LED VT 1  lights, i.e. turns ON. Then each press of the Up key UK 1  increments the vent time from 1 minute to 3 minutes in 0.2 minute increments. Pressing the Down key DK 1  sequentially increments the vent time from 3 minutes to 1 minute in 0.2 minute increments. The selected value is the one last chosen by the operator. 
     Pressing the select key SE 1  thereafter disables the vent time set mode and enables the vent voltage set mode, which the vent speed LED VL 1  indicates by turning ON. Pressing the Up key UK 1  sequentially shifts the vent voltage from 20 to 30, to 40, and 50 in 10 volt increments. The display responds in changes from 1 to 4. Pressing the Down key DK 1  decrements the vent voltage back in 10 volt increments. These voltages are the voltages applied to the motor  24  to control the blower  26 . In an embodiment, the motor  24  is kick started for a short time with 25 volts before reducing it to the lowest 20 volt setting. The selected value is the one last chosen by the operator. 
     The next press of the select key SE 1  disables the vent voltage set mode and enables the stir (or stage two) time set mode so the stir time set LED SL 1  turns ON. Pressing the Up key UK 1  advances the stir time setting changes from 12 to 48 seconds in 12 second increments with the display showing increments of 0.2, 0.4, 0.6. 0.8 minutes. Pressing the down key DK 1  decreases the stir time setting changes from 48 to 12 seconds in 12 second increments with the display showing increments of 0.8, 0.6, 0.4, 0.2 minutes. The selected value is the one last chosen by the operator. 
     The next select key SE 1  press disables the stir time set mode and enables the stir voltage set mode as indicated by the stir speed or voltage LED SL 1  ON. Pressing the Up key UK 1  advances the stir voltage from 70 to 110 in 10 volt increments, and this appears in display selection as 1-5. Pressing the Down key DK 1  decrements the stir voltage from 110 to 70 in 10 volt increments, and this appears in display selection as 5-1. The selected value is the one last chosen by the operator. 
     The next press of the select key SE 1  disables the stir voltage set mode and turns the stir time LED ST 1  and stir speed LED SL 1  OFF. Selected values are used in both the manual and automatic modes. The selected value is the one last chosen by the operator. 
     According another embodiment the process begins with a stir period. 
     The manual mode operates in a manner identical to the automatic mode except the operator must press start/stop key SK 1  to stop the running heat cycle. The chip CH 1  transfers the elapsed time at the moment that the start/stop key SK 1  is pressed to stop the running heat cycle, and stores it as the total time that may be used in the automatic mode. The elapsed time in manual mode begins counting up from 0 to 50 minutes when the start/stop key SK 1  is pressed. The total time in automatic mode begins counting down from the preset time to 00. The heater turns off when the total time reaches 00 and the cool down mode begins. In the manual mode, when there are no factory sets present, the user keeps operating the system and sees when the beans are done, in say 22 minutes. That time and other presets are transferred to the automatic mode. The latter then sets the operation for the same time and presets. The operator then uses the automatic mode if the operator wishes next roast to roast the same quantity of green beans to the same degree of done-ness. A restauranteur, for example, can manually produce a new batch and then arrange to roast other batches of the same beans in the same quantity transferring the results to the auto operating mode. 
     In both the automatic and manual operations, the stir voltage of 70, 80, 90, 100, 110 volts has a time duration of 5 seconds at 120 volts (full speed) then changes to the preset voltage. Also, the ramp time periods divide into 5 increments of 2, 3 and 4 seconds (10/5=2, 15/5=3 and 20/5=4). The stir cycle includes ramping up and ramping down. 
     Operation in the fan-only mode occurs with the heater off and the fan voltage at 80 volts. A cool down mode is, for example, 5 minutes at 90 volts and lasts 2 minutes at 110 volts for a total of 7 minutes. 
     According to an embodiment, the chip CH 1  exhibits a number of preset settings at power up, for example: 
     Presets at power up permit an inexperienced operator to obtain a high quality result without adding additional data. There are many different variations. An example of such presets for one pound of beans is: 
     Total Time Maximum Set Time: 50 minutes (not changeable). This is a safety preset. 
     Vent Time: 1.6 minutes 
     Vent Voltage: 30 Volts, display selection 2 
     Stir Time: 12 seconds (0.2 minutes) 
     Stir Voltage: 80 Volts, display selection 2 
     Cool Down Duration: 7 minutes (not Changeable) 
     The last 5 seconds of stir are at the highest speed available at 110 to 120 VAC. At the conclusion of the 5 seconds at full speed the stir preset speed is restored and will ramp down to vent setting. 
     If no other data is entered, these presets will govern operation in manual or automatic modes. They enable an inexperienced operator to achieve an excellent roast of about one pound of green beans regardless of the bean type, merely by hitting the start button. 
     A user has the option of operating the roaster in the manual or automatic mode. If the user is unfamiliar with the machine or wishes to rely upon factory presets based on prior investigations of satisfactory results, the user can select the automatic mode. On the other hand, if a user has some expertise in roasting to the user&#39;s individual taste, the user may operate the system in the manual mode. After operation in the manual mode, the controller  30  memorizes the user&#39;s manner of operation in the manual mode, and resets the controller  30  so that, in the automatic mode, the system repeats the operation as practiced by the user in the manual mode. The user can repeat the operation again and again in the automatic mode, or operate again in the manual mode to reset the operation in the automatic mode. 
     The manual mode allows judgment of total time. In automatic a 00 comes up on display, and the user must hit the up and down keys UK 1 , DK 1  for total time or simply uses the inputs of manual 
     The following is an example of an automatic operation according to an embodiment. A user plugs the unit into 120 VAC 60 Hertz and Turns on Power Switch PS 1 . The display shows 5 E. 
     The total time key TK 1  is enabled only if the controller  30  is not in any of the manual, automatic, or fan-only modes. If needed the user can turn off these modes. 
     The user presses Total Time Key TK 1 . The total time must be set prior to selecting the automatic mode of operation. (This is not a condition for the manual mode because the time counts up from 0 during operation) In the automatic mode, the display DI 1  shows 0 with the total time LED LE 1  on, and the user enters the total time with the Up key UK 1  or Down key DK 1  to the desired total time. If needed, to cancel any previous total time entries, the user presses Total Time Key TK 1  to cancel Total Time previously set. 
     The user presses the Manual/Automatic key AK 1  and selects the automatic mode. This turns the automatic LED on. 
     The user presses the Start/Stop Key SK 1  to start the cycle. Factory presets for vent fan voltage, vent time, stir fan voltage and stir time are used unless the user has set other values. The user also has the option to press the select Key SE 1  and up key UK 1  and down key DK 1  to other values to change the factory settings or any other previous settings before pressing the Start/Stop Key SK 1 . Again, the selection must be made prior to selecting the manual, automatic or fan-only mode. Control will not start in the automatic mode if Total Time is not set. 
     In automatic the display DI 1  will continue to display the time remaining and alternate between vent and stir until the total time drops to 00 or the user presses the stop/start key. In the automatic mode, the display counts up and in the manual mode it counts down. 
     When the total time counts down to 00, the heater  40  turns off and the Cool Down Stage begins at a fan voltage of 90 volts. The last 2 minutes of the cool down period occurs at 110 volts. The display and heat LED are off during the cool down period. The cool LED is on. 
     When the 7 minute cool down period is complete, the fan and cool down LED turns off. 
     If a second automatic cycle is started without the power switch being turned off and back on the total time will begin at the previous starting time. 
     The following is an example of a Manual Operation according to an embodiment. Here, if the unit is not yet plugged in, a user Plugs the unit into 120 VAC 60 Hertz source and Turns on the power switch PS 1 . The display DI 1  then exhibits an indication such as 5E. 
     The user presses the Auto/Manual key AK 1  and selects the manual mode. This turns on the Manual LED ML 1 . The manual operation also disables the Total Time. 
     The user may utilize the factory presets for vent fan voltage, the vent time, stir fan voltage, and stir time, and then press the Start/Stop Key SK 1 . On the other hand, the user also has the option of pressing the select Key SE 1  and up key UK 1  and down key DK 1  to other values to change the factory settings or any other previous settings before pressing the Start/Stop Key SK 1 . The user presses the Start/Stop Key SK 1  to start the roasting cycle. 
     During the roasting cycle the display DI 1  shows the elapsed time. Once started, the roasting cycle alternates between vent and stir as shown in  FIG. 11 . The user observes the condition of the beans, and when satisfied with their state, presses the start/stop key SK 1 . If the user fails to stop the cycle before a default elapsed such as 50 minutes, the roasting cycle ends. 
     When the start/stop key SK 1  is pressed or the elapsed time reaches the default time such as 50 minutes the heater turns off. The Cool Down Stage then begins at a fan voltage such as 90 volts and continues for a period such as 7 minutes. The last 2 minutes of the 7 minute cool down period is preferably at a higher voltage such as 110 volts. During the cool down period, the display DI 1  and heat LED HL 1  are off and the cool LED CL 1  on. 
     When the 7 minute cool down period is complete, the fan and cool down LED turn off. 
     The controller  30  stores the elapsed time from pressing of the start/stop key SK 1  to start the cycle to the actuation of the start/stop key to end the cycle, or the default time such as 50 minutes stops the cycle, in a total time memory. That time will be displayed when the total time key is pressed with the automatic mode selected. 
     Fan-Only Mode 
     The user Plugs unit into a power source such as 120 VAC 60 Hertz and Turns on Power Switch PS 1 . 
     The user presses the Manual/Automatic key AK 1  to select the fan-only mode. The fan-only mode will be indicated with F 0  being displayed on the display. 
     The fan turns on at 80 volts when the user pressed the start/stop key SK 1 . 
     The fan and display turns off when the user presses the start/stop key again. The display DI 1  will show 5E. 
     According to embodiments of the present invention the beans receive substantially all the heat conductively. In all embodiments they receive the major heat application conductively. This contrasts with other systems where beans substantially receive all the heat by radiation or convection. The total heat required according to embodiments of the invention is substantially less than with radiant or convection heating systems. 
     The use of the fan during operation makes it possible to view the process by getting rid of smoke, oils, and moisture on the glass. The stirring during operation moves the beans against each other, so they knock against each other, to dislodge the bean chaff. According to an embodiment the blower operates at different speeds to stir the beans at different speeds and harmonic vibrations caused by stirring spread out the beans and mixes them. 
     The chaff screen removes the chaff and the HEPA or ULPA filter removes smaller particulate matter. The inside chaff screen prevents the chaff from clogging the HEPA or ULPA filters. 
     According to one embodiment of the invention, the user loads ½ pound or approximately 750 beans, enough to make approximately 15 cups of coffee. According to another embodiment of the invention, the user loads 1 pound or approximately 1,500 beans, enough to make approximately 30 cups of coffee. According to another embodiment of the invention, the user loads 2 pounds or approximately 3,000 beans, enough to make approximately 60 cups of coffee. According to other embodiments of the invention, the number of beans may be more or less and the resulting cups of coffee need not reach exactly these amounts. 
     According to an embodiment of the invention, the user affirms that the process has completed and the beans are done visually. Blowing away the chaff and smoke helps this visual confirmation. 
     According to another embodiment, an ULPA (Ultra-Low Penetration Air) filter is used in place of the HEPA (High-Efficiency Particulate Air) filter. HEPA Filters are rated 99.99% efficient with particles 0.3 microns and larger in diameter. ULPA Filters are rated 99.999% efficient with particles 0.1 microns in diameter. 
     The “fan only” function, which operates with the heater off, serves several purposes. It removes residual heat between consecutive roasts each performed on new batches of beans. This is important because the reproducibility of the second, third, and fourth roasts, etc. depends upon the beginning ambient temperature being substantially the same if the same roasting time is used. However, at the end of each roast the pan is still warm after removal of the beans. Using the fan in the fan-only mode for two or three minutes removes the residual heat and helps assure virtually the same ambient starting temperature. In addition, letting the fan run continuously in the fan-only mode with the heater off (automatic by chip) a filters the air passing through the filter of matter down to 0.1 microns. This removes most pollens, dust, allergens, pollutants down to the 0.1 micron range. 
     Embodiments of the invention permit an experienced person to make individual roasts for special beans. In the manual mode set, the operator can input values that let roasting continue till the operator sees the roast is done. The chip CH 1  enters the value in Auto and the inputted values will be repeated in the automatic mode. To alter the values, the operator inputs new values in the manual mode. This furnishes the system the effect of repeatability of operation. 
     The intermittent venting and stirring allows supervision of the roasting process and results in the ability to handle large quantities of beans in one roast, such as ½ to 2 pounds of beans. Prior art devices have small range of loads, and with moderate range of loads cannot supervise the beans&#39; condition or even measure environment. According to the embodiments disclosed, the operator looks at beans, judges beans&#39; done-ness, and filters out small particles that lets one smell the done-ness of beans. Various of vent-speed vent-time, stir-speed stir-time may be sued. This offers flexibility for various beans. 
     The aforementioned embodiments offer the advantage of employing only one moving part for the stirring of the beans, namely the blower that serves as a single actuator. 
     According to another embodiment of the invention another blower is added to the end of the motor shaft and the air is applied toward the outer periphery of the pan to provide additional stirring of the beans. 
     According to another embodiment shown in  FIG. 13 , a sleeve  110 , connected to the motor  24  and surrounding the shaft of the motor  24 , and coupled by gearing to the motor  24 , drives an internal mechanical stirrer  115  to increase agitation to portions of the beans. According to another embodiment, an external agitator  120  vibrates the pan  12  to create agitation of the beans. One embodiment uses only the mechanical stirrer  115  and another embodiment uses the external agitator  120 . Yet another embodiment uses both. 
     While embodiments of the invention have been described in detail, it will be evident to those skilled in the art that the invention may be embodied otherwise without departing from its spirit and scope.