The coffee 2

The world of coffee.

Coffee processing.
1) wet process, which gives rise to washed coffees. From the freshly harvested fruits it is necessary to extract the beans within a day, otherwise the product suffers. It is therefore a question of eliminating the pulp surrounding the beans. The stages of processing are:
cleaning
sorting
pulping
fermentation
wash
drying
These well executed operations determine the final success of the product.
2) dry process, cheaper. The fruit is spread in thin layers on threshing floors or courtyards. It will be the sun, the pulping machines and then sieves to free the grain of its protections. After decortication, the coffee is sieved with sieves of different diameters and then selected according to the size. Depending on the quality of the selection, the various commercial types will be determined. At this point the coffee is placed in 60 kg bags. about and shipped to the country of consumption.

SUMMING UP

The roasting.

One of the most characteristic and important phases of coffee processing is roasting (roasting). Thanks to it, the aroma and the particular flavor will develop. This procedure consists in supplying heat to the grains that undergo physical transformations in their structure and chemical in their composition, everything depends a lot on the time and the temperature administered.

Partially toasted coffee grain

When the temperature exceeds 100ºC the water inside the grain begins to evaporate and the internal pressure of the steam causes the cells to swell making them less elastic, elongating them and increasing the tensions until they are partially broken. As the grain increases in volume, it detaches due to the difference in expansion and the latter from green begins to take on a yellow-brown color. In the last phase of the process, from about 150ºC to 220ºC, from endothermic reactions, thanks to the heat supplied from the outside, we pass to exothermic reactions which themselves generate heat. The brown color intensifies, the sugars caramelize, and chemical transformations take place (including -condensation and polymerization reactions) which will determine the development of taste and aroma. With roasting, coffee increases in volume by 25-35% and weight decreases by 18-22%; caffeine does not undergo significant changes. At this moment, to prevent the coffee from carbonizing, the action of heat both from the external source and from the exothermic reactions coming from the inside of the bean must be abruptly stopped, cooling it rapidly with flows of cold air. The degree of roasting regulates the color of the bean which is indicated as light, medium and dark; Factors such as acidity and body are also regulated by roasting, as are almost all the characteristics of the finished product.

PACKAGING

Green coffee keeps for a long time without problems, but after being roasted the taste and aromatic characteristics last a few months. For this reason (and also because the degree of roasting varies from country to country) roasting takes place in the consuming country. Roasted coffee, if left open, loses most of its characteristics in just fifteen days; for this reason, the rapid packaging of still hot beans is very important. However, due to the combustion, the toasted beans continue to release gas and this fact is taken into great consideration for the packaging in order to avoid that the internal pressure causes the packaging to open (burst).
Four methods are used for packaging:
with non-hermetic closure: the coffee is closed in bags with 1 or 2 small holes for the escape of gases and the entry of air. The duration is approximately one month. Suitable solution for selling the product in a short time.
vacuum: the package is deprived of air and with a one-way valve only the gases are allowed to escape. This system is mainly used for coffee beans and allows optimal conservation for about six months.
with pressurization: the coffee is packaged in watertight metal containers creating a vacuum and introducing inert gases (nitrogen or carbon dioxide) at low pressure. Unidirectional safety valve allows the escape of excess gases. It allows a long conservation of the product (even more than 3 years) but more expensive than the other methods.
high vacuum: the coffee is packaged by eliminating the air inside the container, but in this way it also sucks in part of the volatile aromatic substances and carbon dioxide that are released from the beans after roasting. It is normally used for ground coffee and can be kept for about three months. However, degassing impoverishes the mixture of aromas

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