RU2712552C1 - Two-step coffee beans roasting method - Google Patents

Abstract

FIELD: coffee industry.

SUBSTANCE: first degree of roasting is performed as follows. Green coffee beans are loaded into the frying chamber. Coffee beans are fried in a “boiling” air flow till the first “crack”. In frying chamber from 1 to 3 l of water is injected. Coffee grains are cooled down. Coffee grains are unloaded from the frying chamber into the "storing" bin. Coffee beans "storing" stage is carried out from 1–3 days. Second step of roasting is performed as follows. Roasting chamber is heated to the temperature at which the previous stage of roasting at the first step has been stopped. "Stored" coffee beans are loaded into the fretting chamber. Coffee grains are cooked till the second "crack". Specified volume of water is injected into the frying pan. Coffee grains are cooled down and coffee beans are passed through the rock separator. Coffee beans are unloaded into a storage bin.

EFFECT: invention ensures improvement of organoleptic indices of the ready product, slowing down of caramelization process, which allows maximum preservation of natural sugars inside the end product.

1 cl, 1 dwg

Description

The present invention relates to the food industry and can be used in the field of processing coffee products, mainly coffee beans.

BACKGROUND

Several methods are known for roasting coffee beans. One of them is a method of preparation (roasting) of coffee beans, in which coffee beans are roasted with a coolant, which is a mixture of air with the products of combustion of liquid or gaseous fuels, with a temperature of 215-220 ° C in a rotating roasting drum for 20-23 minutes, and before the end the roasting process, the coffee beans are moistened with water sprayed inside the drum for 50 seconds in order to bring the humidity of the coffee beans to 4% (see Kretov I.T., Ostrikov A.N., Kravchenko V.M. "Technological equipment of food processing enterprises atnoy industry ": Tutorial - Voronezh. Voronezh State University Publishing House, 1996. - 448 c, 274-275)...

The disadvantages of the above method are significant energy consumption, a long roasting process and a very low quality of the finished product due to the use of a mixture of air with combustion products of liquid or gaseous fuels, which may contain harmful carcinogens, as a heat carrier.

There is also a known method of roasting coffee beans, in which coffee beans are roasted for 4 minutes with a coolant, which is used as superheated steam of atmospheric pressure with a temperature of 280-380 ° C and a blowing speed of 2.8-3.6 m / s, and in the middle and at the end of the roasting process, the coffee beans are moistened with finely dispersed moisture for 10-15 seconds, bringing after the first moistening to a moisture content of 8% and 5-6% after the second wetting (see Copyright Certificate SU 1734642 A1, A23F 05/04, publ. 05/23/1992).

The disadvantage of this method is the relatively high energy consumption and relatively low quality of the resulting product, as the roasting process does not include, for example, processing coffee beans in a closed cycle by superheated steam. In addition, the method does not provide for the removal of non-condensable gases formed as a result of thermal decomposition of coffee products, the recirculation of which is not only impractical, but also harmful, since the fumes (a mixture of evaporated moisture from coffee beans and non-condensable gases - thermal decomposition products of coffee beans) during roasting are 12- 20% of the total mass of the product and includes toxic components that have a negative effect on human health.

Another known method involves the preparation of raw materials and their subsequent heat treatment with superheated steam with intermediate wetting of the product obtained in the process of heat treatment of raw materials, and the preparation of raw materials is carried out by pre-heating it in a conductive heating chamber in two successive stages, the first of which is heated air to a temperature of 45-50 ° C, and in the second stage - steam to a temperature of 55-65 ° C, and then carry out the drying of the product in the drying chamber with air to temperatures of 85-95 ° C, and the spent superheated steam with a temperature of 130-140 ° C is discharged to a heat exchanger-recuperator for heating air to a temperature of 110-120 ° C with subsequent supply for preheating the product in the second stage, while the vapor evaporated from the product moisture is transferred to a condensate collection tank, from where it is partially sent to intermediate moistening of the product in the frying chamber, and partially transferred to the steam generator, the resulting steam is overheated in the superheater and fed into the frying chamber in a closed cycle, forming non-condensing gases in the amount of 8-10% are removed from the superheated steam recirculation loop, and the exhaust air with a temperature of 90-100 ° C is sent from the drying chamber to the heat exchanger-recuperator and then to preheat the product at the first stage with subsequent supply to the dryer, then into the drying chamber in a closed cycle (see RF patent RU 2265370 C1, A23L 1/10, 12/10/2005).

The disadvantage of this technical solution is the relatively low quality of the finished product.

SUMMARY OF THE INVENTION

The essence of the invention lies in a two-stage method of roasting coffee beans. Coffee beans are roasted in stages at high temperatures, followed by cooling with water. Stage-by-stage roasting occurs with a break of several days (from 1 to 3 days, depending on the country of origin of the grain, the height of its growth, the composition of the roasted mixture or the final roasting temperature), during which the so-called “aging” of coffee beans occurs, which allows for smooth Changes in the crystal lattice of coffee beans.

The present invention is to eliminate the disadvantages of the prior art. The main objective of the invention is the need to achieve maximum preservation in the final product of all aromatic and taste qualities of coffee. Another objective of the invention is to increase the strength of roasted coffee beans, which helps to prevent destruction and dust formation during packaging, transportation and storage of the finished product.

The technical result consists in improving the organoleptic characteristics of the finished product, as well as in slowing down the caramelization process, which allows maximum preservation of natural sugars inside the final product.

The technical result is achieved due to the introduction of a two-stage method of roasting coffee beans with a break of several days, in particular due to a method of two-stage roasting of coffee beans, containing

the first stage of frying, including the following steps:

loading green coffee beans into the brewing chamber,

roasting coffee beans in a "boiling" air flow to the first "crack",

injection into the fryer of a predetermined volume of water, cooling coffee beans,

unloading coffee beans from the roasting chamber into the hopper for “aging”,

“Aging” of coffee beans from 1-3 days;

the second stage of frying, including the following steps:

heating the frying chamber to a temperature at which the previous frying step in the first stage was stopped,

loading "reclaimed" coffee beans into the roasting chamber,

roasting coffee beans to the second "crack",

injection into the frying chamber from 1 to 3 liters of water,

coffee bean cooling

passing coffee beans through a stone trap, unloading coffee beans into a storage bin.

The above and other objectives, features, advantages, as well as the technical relevance of the present invention will be more apparent from the following detailed description of the invention with reference to the accompanying drawing.

BRIEF DESCRIPTION OF THE DRAWING

The figure 1 shows a diagram of a two-stage roasting of coffee beans, where

1 - a hopper for green coffee beans, 2 - a hopper for “aging” coffee beans, 3 - a roasting chamber, 4 - a cooler, 5 - a stone trap, 6 - a hopper for storing finished roasted coffee beans.

DETAILED DESCRIPTION OF THE INVENTION

At the first stage of roasting, green coffee beans from the hopper (1) are loaded into the roasting chamber (3) of Sivetz American equipment, which uses the technology of roasting in a "boiling" air space (stream). In the course of this technology of roasting, coffee beans begin to be roasted “from the inside”, which, in turn, makes all substances and aromas located directly inside the coffee bean to quickly activate. Within 7-8 minutes, the temperature in the frying chamber rises to 200 ° C to the so-called first "crack". The first “crack” is the noisy release of accumulated water vapor and the extrusion of CO ₂ from the core of the grains. Coffee beans emit a series of clicks that start quietly, accelerate, reach a peak, and then subside. After that, water is injected into the frying chamber from 1 to 3 l, depending on the loaded volume of coffee beans. After this, cooling occurs in the cooler (4) and the grain is unloaded from the frying chamber into the hopper (2) for “aging”, where coffee beans are “aged” for 1 to 3 days. The period of “maturation” depends on the country of origin, the height of growth, the composition of the mixture (if it takes place), or the final frying temperature.

At the second stage of roasting, the "settled" coffee beans are again loaded into the roasting chamber and roasted for 5-6 minutes. When starting frying to the required temperature, the frying chamber is preheated to the temperature at which the previous frying process was stopped (up to 200 ° C). Upon reaching the second "crack" stop frying in manual mode. With this type of pre-frying, the frying chamber of the machine is preheated also to 200 ° C. When re-frying in a time interval, the automatic stop time of the frying process is programmed on the control panel of the frying machine. When this time is reached, the machine automatically stops the process. In each of the after-frying cases, after stopping the frying process, water is injected into the frying chamber for 3-5 minutes. The finished product arrives for storage in the hopper (6) for storing the finished roasted coffee beans.

Such a two-stage roasting process is necessary to achieve a balance of the physicochemical properties of coffee beans. This is due to the fact that, like any solid body, coffee bean has a crystal lattice. With a sharp influence of high temperatures on the grain (steam, high frying temperature), the crystal lattice of green grain begins to rapidly collapse. When the roasted coffee beans are cooled, the crystal lattice is destroyed, and before the formation of a new lattice, a sharp and quick loss of aromas, oils and other substances contained in coffee occurs, the sugar present in the grain is almost immediately caramelized and evaporates. With the two-stage roasting method according to the present invention, the destruction and change of the crystal lattice occurs in stages, which is more rational from the point of view of preserving all the aromatic and taste qualities of coffee beans in the final product, as well as slowing down the caramelization process and the maximum possible preservation of natural Sugars inside the final product.

As an example, consider the phased roasting of the complex coffee blend “Bengal Tiger”, consisting of several types of alpine arabica.

The composition of the mixture includes Indonesia Java Blawan Estate, India Monsood Malabar AA, Indonesia Sulawesi Toraja Gr. 1, Indonesia Sumatra Gayo Belangi Gr. 1, India Plantetion A Bababudan, which are placed in a fryer, preheated to 150 ° C, in equal proportions for one frying. After loading the mixture, the temperature in the frying chamber drops to about 100 ° C, then in a very short period of time from 6 to 8 minutes there is a sharp set of temperature up to 200 ° C (to the first "crack"). In this case, the “outflow" of the temperature can be 2–3 ° С (202–203 ° С), since not all coffee beans included in the mixture are roasted to the desired temperature at the same time. After that, the frying process stops, at the moment of stopping from 1 to 3 liters of water is automatically injected into the frying chamber. The roasted mixture is unloaded into the cooler, then the coffee beans are placed in a special container - a hopper for “aging” coffee beans, where it is aged for three days. After that, the coffee beans are reloaded into the roasting chamber preheated to 150 ° C. Within 5-6 minutes, the temperature rises sharply to 220 ° C, that is, to the second "crack". The second “crack” is characterized by the appearance of the first drops of oil on the surface of the grains. Then, water is injected in approximately the same volume as in the first stage of roasting (1-3 liters), cooling in a special container, after which coffee beans are passed through a stone trap (5), in which, in the presence of stones or foreign impurities, they separation from coffee beans. Next, coffee beans are laid out in a special container - a storage hopper, in which there is a process of degassing coffee beans and mixing the aromas and tastes of the original mixture. Then the roasted coffee beans are sent for packaging.

As a second example, consider the step-by-step roasting of a complex branded Inca mixture.

The composition of the mixture includes Columbia Supremo, Guatemala Fancy SHB, Costa Rica Tarrazu Colibri SHB, Honduras San Marcos SHG, which are placed in a fryer, heated to 148 ° C, in equal proportions for one frying. After loading the components of the mixture, the temperature in the frying chamber drops to about 100 ° C, then in the period from 5 to 7 minutes there is a sharp set of temperature up to 200 ° C degrees (to the first "crack"). “Departure” of temperature can be 2-3 ° С (202-203 ° С), since not all components included in the mixture are fried to the required temperature at the same time. Further, the frying process stops, at the moment of stopping, 1 to 3 liters of water are automatically injected into the fryer. After the roasted mixture is unloaded into the cooler, then the coffee beans are placed in a special container - a hopper for “aging”

coffee beans, where it is aged for two days. After that, the coffee beans are reloaded into the roasting chamber preheated to 148 ° С, within 4-5 minutes there is a sharp set of temperature up to 220 ° С (to the second "crack"). Then, water is injected in approximately the same volume as in the first stage of roasting (1-3 liters), cooling, after which coffee beans are passed through a stone trap. Next, coffee beans are laid out in a special container - a storage hopper, in which the process of degassing coffee beans, as well as mixing the tastes and aromas of the original mixture. Then the roasted coffee beans are sent for packaging.

As a third example, consider the roasting of the Chegevara Mix coffee blend.

The composition of the mixture includes the following components: Nicaragua SHG EP, Ethiopia Yirgacheffe and Tanzania Oldeani Estate AA, which are placed in a fryer, heated to 145 ° C, in equal proportions for one frying. After loading the components of the mixture, the temperature in the frying chamber drops to about 100 ° C, then in the period from 5 to 6 minutes there is a sharp set of temperature up to 200 ° C (to the first "crack"). “Departure” of temperature can be 2-3 ° С (202-203 ° С), since not all components included in the mixture are fried to the required temperature at the same time. Further, the frying process stops, at the moment of stopping, 1 to 3 liters of water are automatically injected into the fryer. After the roasted mixture is unloaded into the cooler, then the coffee beans are placed in a special container - a hopper for “aging” coffee beans, where it is aged for a day. After that, the coffee beans are reloaded into the roasting chamber preheated to 145 ° С, within 4-5 minutes there is a sharp set of temperature up to 220 ° С (up to the second "crack"). Then, water is injected in approximately the same volume as in the first stage of roasting (1-3 liters), cooling, after which coffee beans are passed through a stone trap. Next, coffee beans are laid out in a special container, in which the process of degassing coffee beans, as well as mixing the tastes and aromas of the original mixture. Then the roasted coffee beans are sent for packaging.

The fewer components that make up the coffee mixture, the less time is needed to “withstand” the beans between the stages of roasting and the lower the temperature of the heated roasting machine should be.

The described method of roasting is applicable to work on the roasting equipment of the American company Sivetz Coffee INC7. To simplify the understanding of the implementation of the method disclosed in the present invention, FIG. 1 shows a simplified diagram of a two-stage roasting of coffee beans.

Claims (1)

A two-stage method of roasting coffee beans, comprising a first stage of roasting, which includes the following steps: loading green coffee beans into the roasting chamber, roasting coffee beans in a "boiling" air flow to the first "crack", injecting 1 to 3 liters of water into the roasting chamber, cooling coffee beans, unloading coffee beans from the frying chamber into the hopper for “aging”, “aging” of coffee beans from 1-3 days; the second stage of roasting, which includes the following stages: heating the roasting chamber to a temperature at which the previous stage of roasting at the first stage was stopped, loading the “recovered” coffee beans into the roasting chamber, roasting the coffee beans to the second “crack”, injection into the roasting chamber of a given volume water, cooling coffee beans, passing coffee beans through a stone trap, unloading coffee beans into a storage bin.

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