IES990741A2

IES990741A2 - A manufacturing process for coffee products

Info

Publication number: IES990741A2
Application number: IE19990741A
Authority: IE
Inventors: David Mckernan
Original assignee: David Mckernan
Priority date: 1999-09-02
Filing date: 1999-09-02
Publication date: 2001-04-04
Also published as: GB2355642A; GB2355642B; IE20000694A1; IES20000695A2; GB0021722D0

Abstract

Selected amounts of green coffee beans of a single type are weighed (15) and delivered to a pre-heated roaster (16). Within the roaster (16), the green coffee beans are slowly roasted in a controlled manner over a period of about twenty-three minutes to produce a batch of roasted coffee beans. Said batch of roasted coffee beans is discharged to a cooler where they are gradually cooled. After cooling, the roasted coffee beans are immediately packaged. Prior to packaging, the roasted coffee beans may be blended with other varieties of bean. Also, the beans may be ground if desired. <Figure 1>

Description

“A Manufacturing Process" Introduction This invention relates to an improved manufacturing process for producing a coffee product Discussion of Prior Art The commercial production of coffee products such as roasted coffee beans and ground roast coffee usually involves the blending of selected quantities of two or more green coffee beans to form a batch of mixed green coffee beans which is subsequently roasted. It will be appreciated that different coffee beans will have different optimal roasting temperatures and conditions. Therefore, because a mixture of different green coffee beans is being roasted, at least some of the beans are roasted under less than ideal conditions with a consequent loss in quality. Further, after roasting, from a production point of view, it is desirable to provide forced cooling of the roasted coffee beans prior to grinding and/or packaging. In many cases, this is done by means of a cooling water spray discharged over the hot roasted coffee beans with or without additional air cooling. This provides a relatively rapid cooling of the roasted coffee beans, typically in the order of 2 to 3 minutes. Obviously, minimising cooling time is desirable from a production point of view, however, the rapid forced cooling leads to a loss in quality. The above-mentioned limitations are generally considered acceptable in the interest of convenience and costs in respect of commercial coffee production processes.

The present invention is directed towards overcoming these problems and in providing an improved production process for the commercial production of high quality coffee products.

Summary of the Invention According to the invention, there is provided a manufacturing process for a coffee product which includes the steps of delivering a measured batch of green coffee beans to a roaster, roasting the green coffee beans in the roaster for a pre-desired time at a pre-selected temperature to produce a batch of roasted coffee beans, discharging the batch of roasted coffee beans from the roaster to a cooler, cooling the roasted coffee beans, optionally grinding the roasted coffee beans, and packing the roasted coffee beans or ground coffee.

Ideally, according to the invention, the batch of green coffee beans comprises a single type of coffee bean. Thus, advantageously, the optimal roasting conditions such as temperature and time can be selected for the particular green coffee bean being roasted at any time. Thus, all green coffee beans are individually roasted to provide roasted coffee beans of high quality.

Preferably, a slow roasting of the green coffee beans is carried out. Typically, the slow roasting is earned out over a period of about 20-26 minutes, and most preferably about 23 minutes. The temperature at which the green beans are roasted will depend on the particular bean being roasted, the optimum roasting temperature for that coffee bean being selected. This slow roasting differs from the more usual commercial roasting which typically takes in the order of 8 minutes, and has been found to enhance the flavour and organoleptic properties generally of the roasted coffee beans.

In a particularly preferred embodiment, the'cooling of the roasted coffee beans is carried out by discharging the roasted coffee beans from the roaster onto a cooling tray having a perforated base and forcing cooling air up through the base over the roasted coffee beans whilst moving the roasted coffee beans about the base by means of a paddle which travels over the base above the base. The paddle turns or rolls the roasted coffee beans over on the tray to ensure an even and thorough cooling of the roasted coffee beans. Preferably, a number of paddles are radially mounted above the base on an associated centrally mounted rotatable drive shaft which is drivably connected to a prime mover such as an electric motor.

Downstream of the cooler, the roasted coffee beans are preferably delivered through a de-stoner for removing stones and other foreign matter which might be entrained in the batch of roasted coffee beans.

If desired, the roasted coffee beans can be ground before packaging.

In another aspect, the invention provides apparatus for carrying out the process of the invention substantially as herein described.

Detailed Description of the Invention The invention will be more dearly understood by the following description of an embodiment thereof, given by way of example only, with reference to the accompanying drawing which is a schematic illustration of a coffee manufacturing process according to the invention.

Referring to the drawing, green coffee beans of a selected single type are delivered into an inlet hopper 10 which has a screen 11 to trap any large pieces of foreign matter, the green coffee beans passing through the screen 11 for collection at a bottom of the hopper 10. A discharge pipe 12 has an inlet 13 at a bottom of the hopper 10 and an outlet 14 which discharges into a weigher 15. A vacuum transfer system is provided for feeding the green coffee beans from the hopper 10 through the pipe 12 to the weigher 15.

A batch of green coffee beans of a desired quantity is collected in the weigher 15 and subsequently discharged into a preheated roaster 16 which is at a charging temperature of about 250°C. Within the roaster 16, the green coffee beans are subjected to an optimum roasting temperature assodated with said green coffee bean type for a preset period of time, preferably about 23 minutes to provide a slow roasting of the green coffee beans.

Within the roaster 16, the green coffee beans are cooked in three stages. In a first stage the green coffee beans are heated to slightly less than boiling point. The green coffee beans will swell and the water inside the green coffee beans begins to steam. The beans audibly crack as woody structures are broken down. In stage 2, after most of the water has left the beans, the bean cells are turned into starch and finally sugars. These sugars then caramelise, adding to the brown colour of the bean and aromatic oils present in the beans volatise to the surface. In a third stage, the expansion of the oils causes a second crack and the roasting process proceeds much more quickly at this stage. Many of the aromatics present will either vaporise entirely or develop other chemical parts, one being the oily appearance.

After roasting, hot roasted coffee beans are discharged from the roaster 16 to a cooler 18. The cooler 18 has a perforated tray 19 mounted within a casing 20 having a base 21 and an upstanding peripheral side wall 22. The tray 19 is mounted spaced below an upper rim of the side wall 22 to retain the roasted coffee beans on the tray 19. Rotatable paddles 25 are radially mounted on a central drive shaft 26 which projects up through the tray 19, and may be driven by any suitable drive means such as an electric motor (not shown), to sweep the paddles 25 over the surface of the tray 19 to turn the hot roasted coffee beans for cooling on the tray 19. A fan 28 delivers ambient air through an air line 29 into a bottom of the casing 20 for forcing the air upwardly through the perforated tray 19 for cooling the hot roasted coffee beans. The cooling of the hot roasted coffee beans takes about 7 minutes.

The cooled roasted coffee beans are conveyed from the tray 19 through a vacuum transfer pipe 30 to a de-stoner 32 within which any entrained stones or other foreign matter is removed from the roasted coffee beans.

Downstream of the de-stoner 32, the roasted coffee beans may be delivered direct to a packaging station 35 or alternatively delivered through a grinder 36 prior to packaging 35. In another alternative, the roasted coffee beans may be delivered to a mixer 37 within which they are combined with one or more other types of roasted coffee beans prior to packaging 35. The blend created in the mixer 37 may be delivered through the grinder 36 prior to packaging 35 in an alternative arrangement.

It will be noted that instead of providing the mixer 37, mixing of two or more types of roasted coffee beans may be carried out in the cooler 18, using the paddles 25 to mix the different roasted coffee beans together on the tray 19.

At the packaging station 35, whole roasted coffee beans, or ground coffee as the case may be, are delivered into a packaging machine which forms and fills a predetermined sachet size with a measured quantity of the coffee product.

The invention is not limited to the embodiments hereinbefore described which may be varied in both construction and detail.