One of the main elements of technological processing of coffee beans, on which, perhaps, all the skill is focused and the talent of coffee producers is manifested, is the roasting process. Ripe coffee beans are usually dark gray or greenish gray, have an unpleasant astringent taste, do not have an aroma, and are difficult to grind..
How to roast coffee beans at home, the temperature and speed of roasting, the degree of roasting coffee beans.
The significance of roasting as a technological process lies in changing these qualities of the beans and creating the best possible taste, color and aroma of coffee, so that it displays the inherent aroma and properties of a tonic drink only. It is thanks to the roasting of coffee that it becomes “brown gold”, while the quality of roasting largely determines the grade of coffee.
. It is no exaggeration to say that in the production environment this is a fairly responsible operation in the technology of preparing coffee, requiring special skills in the use of technology, we can say a kind of art that only rare roasting specialists with extensive experience and high qualifications own.
The process of roasting coffee beans requires strict observance of all the nuances of its technology, because the slightest deviations from it or an extra few minutes of overexposure can finally ruin the taste of coffee. It is necessary to establish up to seconds when the coffee beans are ready, that is, when a kind of “taste peak” appears in them, and immediately begin to cool them. Then, again under control, he must lie down.
Roasting coffee beans is usually carried out in a roaster (coffee oven) – at a temperature in the range of 180-200 degrees and continuous stirring, as a result of which uniform roasting of beans is achieved. At the same time, it is very important to monitor temperature fluctuations, maintain it and predetermined limits, skillfully regulate heating, since at higher temperatures than coffee beans can be charred quickly.
No less significant for the quality of roasting grains and the speed of roasting. If this process is carried out in a fairly fast mode, the coffee grains begin to “sweat”, that is, fat appears on their surface, with slow roasting, the inside of the grain will remain unburnt and the coffee from such beans will be less aromatic than from the same beans, but well-roasted. In this case, it is simply simply dried and its extractive qualities are significantly reduced.
Composition and properties of roasted coffee beans.
Roasted coffee beans contain about 30% water-soluble substances. In the process of roasting coffee beans, complex physicochemical and biochemical processes occur, as a result of which the volume of coffee mass increases 1.3–1.5 times, and their weight decreases by an average of 18%. This is due to the loss of water by the grains and the decomposition of organic substances that are part of mature but not dried coffee beans.
At the same time, other properties of coffee also change; caffeine is formed in it – a complex bouquet of aromatic substances. It contains about 70 different aromatic substances from 2000, which are identified in coffee. These are mainly the decomposition products of proteins, sugars, fat: methyl alcohol, acetic acid, pyridine, maltol and others. All this variety of chemical compounds creates the aroma and taste of coffee..
However, the alkalioid trigonellin, which at the same time breaks down and turns into pyridine, is the most effective in giving coffee a pleasant specific aroma. Caffeine, trigonellin and sugar caramelization products give brewed coffee a pleasant bitterness, and chlorogenic acid – an astringent taste. Carameline in combination with other substances gives the grains a brown color. When evaluating grains, this color is compared with grains that have a reference color.
The procedure for roasting coffee beans at home in a pan in the oven.
For roasting coffee grains at home, appropriate utensils are produced and are on sale, for example, cylindrical roasts. In everyday life, however, coffee beans are roasted in a good cast iron or iron pan. But it should be used exclusively for this purpose, as coffee easily absorbs odors.
At the same time, first the coffee grains are washed in a colander with water for 2-3 minutes. According to some recommendations, it should be kept in water for at least 10 minutes. Then they should be dried with a well-absorbing towel or sprinkled on a spread canvas napkin to dry.
Coffee beans are washed if they want to refresh the smell of beans from the store. Then they are poured into the pan with a layer of 2-3 cm, put in the oven and, periodically stirring, check their readiness. The degree of roasting is regulated by the intensity of the temperature and the duration of heating. You should wait until the beans crackle lightly and when they get an intense brown color and become dull, it is believed that the coffee beans are well roasted.
It is impossible to make too intense a fire – the grains will quickly burn out and become bitter. To make sure that the coffee grains are ready, you need to bite one grain, and you will feel it. After roasting, the coffee grains should be quickly cooled. Then they are poured into a container with an impervious tightly lapped lid and stored in a dark, dry place, preferably at a low temperature.
The degree of roasting coffee beans.
To give a single recipe, to what extent it is difficult to roast coffee. The fact is that there are different types of coffee and each of them requires its specific roasting conditions and different time for this, but the main thing is that the different tastes of the coffee consumer, which is why subjectivity arises in assessments.
For some, coffee will seem overcooked. For others, normal. Still others are satisfied with what they are. An important role in roasting coffee beans is played by established tastes, habits and national traditions. Based on the whole variety of tastes, coffee grains are prepared:
Strong roasted, dark roasted coffee.
Light or light fried.
Italian, French, American fried.
Typically, most people prefer moderate-roasted coffee grains, as excessive roasting leads to carbonization – carbonization, and weak – to the manifestation of the highest acidity of coffee. But this is a matter of taste. The French and Italians, for example, value highly roasted coffee above all else. It is recommended that you drink light or medium roasted coffee the day after breakfast and during the day, while heavily roasted coffee will be good in the afternoon.
Based on Coffee, 333 recipes.