Coffee Processing & Roasting
Processing
It takes five years for a tree to produce good fruit, however after 15 years a coffee tree is on the decline and its output is depreciated. When you purchase 500 grams of coffee, ponder the thought that this is a little more than the output for a tree in one year!
And what beverage requires so much careful preparation? First the cherries have to be picked. Harvesting is a time-intense labour, almost every human that can walk or stand – including neighbours, family and friends are called upon to pick the cherries. A good worker can pick 90 kilograms in a day, but the beans do not ripen all at once so there could be four, five, even six excursions back to the one tree. The beans then have to be extracted from the gummy fruit and the various layers inside.
The wet extraction method
In this process, the cherries go into a machine called a pulper which scrapes away the gummy outer layer. From there they move into large concrete tanks where they are soaked and fermented for a day. This gets rid of the remaining outer layers. They are washed again several times in clean water and put out to dry in the sun in machine dryers. The drying process here is much quicker, and the wet method has many advantages. It is more precise, more thorough and there is much better control over fermentation, so the chances are the best coffee will come from the wet method.
Roasting
It was probably an Ethiopian some time in the 13th century who first thought of roasting coffee. For nearly 700 years the system has hardly changed. It was common to roast the coffee at home or in the coffeehouse immediately before drinking.
In the mid 19th century the cylinder roaster was developed, a perforated cylinder which turned over fire and in later years over gas or electricity. With the 20th century the coffee merchants developed modern industrial equipment for roasting. First there were huge cylinders, then they developed systems for delivering hot air at high speed across the beans. Next came the continuous roasters with beans pouring through in a never ending system, being heated to 240 degree Celsius for periods of eight to twelve minutes.
In the roasting process there is a change in the chemical composition of the bean; various elements – mainly sucrose are decomposed and carbon dioxide and carbon monoxide are released. The result is an astonishing loss of weight, anything up to 20 percent. Depending on the darkness of the roast, bulk can go up by 80 percent.
There was a need to suit a variety of palates. Not everyone likes the same roasts and this is why different roast degrees were developed. There are four main categories:
Light Roast – for delicate, mild beans. Good for breakfast coffee, the coffee you might drink with milk and sugar.
Medium Roast – Normal coffee the way the French, Americans and Australians like it.
Full Roast – Very dark in colour, a bitter powerful drink, and the way they like it in Italy or Vienna.
Double Roast – Almost black. Not good for the subtleties of the original flavour, but very strong and bitter. This is right for espresso coffee or the thick syrupy drink that is the passion in Latin America or Turkey.
Cre8ive Coffee beans and blends can be found here.