coffee & roasting
Coffee Berries and their seeds undergo several processes before they become the familiar roasted coffeeintroduction
Coffee is a brewed drink prepared from roasted seeds, commonly called coffee beans, of the coffee plant. They are seeds of coffee cherries that grow on trees in over 70 countries. Green unroasted coffee is one of the most traded agricultural commodities in the world. Today, coffee is one of the most popular beverages worldwide.
The energizing effect of the coffee bean plant is thought to have been discovered in Yemen in Arabia and in the northeast region of Ethiopia, and the cultivation of coffee first expanded in the Arab world. The earliest credible evidence of coffee drinking appears in the middle of the fifteenth century, in the Sufi monasteries of Yemen in southern Arabia. From the Muslim world, coffee spread to the rest of Europe, Indonesia, America. Coffee has played an important role in many societies throughout history.
Coffee berries, which contain the coffee seed, or “bean”, are produced by several species of small evergreen bushes of the genus Coffea.
The two most commonly grown are the highly regarded Coffea arabica, and the ‘robusta’ form of the hardier Coffea canephora. Both are cultivated primarily in Latin America, Southeast Asia, and Africa. Once ripe, coffee berries are picked, processed, and dried. The seeds are then roasted to varying degrees, depending on the desired flavour. They are then ground and brewed to create coffee. Coffee can be prepared and presented in a variety of ways. An important export commodity, coffee was the top agricultural export for twelve countries in 2004, and it was the world’s seventh-largest legal agricultural export by value in 2005. The method of brewing coffee has been found to be important to its health effect.
roasting
Coffee berries and their seeds undergo several processes before they become the familiar roasted coffee.
Berries are traditionally selectively picked by hand; a labour intensive method, it involves the selection of only the berries at the peak of ripeness. More commonly, crops are strip picked, where all berries are harvested simultaneously regardless of ripeness by person or machine. After picking, green coffee is processed by one of two methods — the dry process method, simpler and less labour intensive as the berries can be strip picked, and the wet process method, which incorporates fermentation into the process and yields a mild coffee.
Then they are sorted by ripeness and colour and the flesh of the berry is removed, usually by machine, and the seeds – usually called beans – are fermented to remove the slimy layer of mucilage still present on the bean. When the fermentation is finished, the beans are washed with large quantities of fresh water to remove the fermentation residue, which generates massive amounts of coffee wastewater. Finally, the seeds are dried. The one method of drying coffee is using drying tables. In this method, the pulped and fermented coffee is spread thinly on raised beds, which allows the air to pass on all sides of the coffee, and then the coffee is mixed by hand. In this method the drying that takes place is more uniform, and fermentation is less likely.
Most African coffee is dried in this manner and certain coffee farms around the world are starting to use this traditional method. Next, the coffee is sorted, and labelled as green coffee. Another way to let the coffee beans dry is to let them sit on a concrete patio and rake over them in the sunlight. Some companies use cylinders to pump in heated air to dry the coffee beans, though this is generally in places where the humidity is very high.
the actual roasting process
Coffee is usually sold in a roasted state, and with rare exceptions all coffee is roasted before it is consumed. It can be sold roasted by the supplier, or it can be home roasted. The roasting process influences the taste of the beverage by changing the coffee bean both physically and chemically. The bean decreases in weight as moisture is lost and increases in volume, causing it to become less dense. The density of the bean also influences the strength of the coffee and requirements for packaging. The actual roasting begins when the temperature inside the bean reaches approximately 200 °C (392 °F), though different varieties of beans differ in moisture and density and therefore roast at different rates.
During roasting, caramelization occurs as intense heat breaks down starches in the bean, changing them to simple sugars that begin to brown, changing the colour of the bean. Sucrose is rapidly lost during the roasting process and may disappear entirely in darker roasts. During roasting, aromatic oils, acids, and caffeine weaken, changing the flavour; at 205 °C (401 °F), other oils start to develop. One of these oils is caffeol, created at about 200 °C (392 °F), which is largely responsible for coffee’s aroma and flavour. At Beans About Coffee we only use the drum roasting process. We believe that with drum roasting we can create coffee with a much richer and fuller mouth feel. Drum roasting has the great ability to bring out the nuances of flavour as it is much more controllable. Our goal is to have fresher fuller coffee available thus we have invested in small drum roasters so that we roast only within our consumption, usage, and needs in our own specific areas.
Grading
Depending on the colour of the roasted beans as perceived by the human eye, they will be labelled as light, medium light, medium dark, dark or very dark
A more accurate method of discerning the degree of roast involves measuring the reflected light from roasted beans illuminated with a light source in the near infrared spectrum. This elaborate light meter uses a process known as spectroscopy to return a number that consistently indicates the roasted coffee’s relative degree of roast or flavour development.
Roast Characteristics
Darker roasts are generally smoother because they have less fibre content and a more sugary flavour.
Lighter roasts have more caffeine and a stronger flavour from aromatic oils and acids otherwise destroyed by longer roasting times. A small amount of chaff is produced during roasting from the skin left on the bean after processing. Chaff is usually removed from the beans by air movement.
Decaffeination
Beans are decaffeinated when they are still green
There are various methods used to remove caffeine from the coffee bean. We only use coffee beans that went through the CO2 process. This method uses two natural elements, pure water and carbon dioxide (together they make “Sparkling Water”) to extract caffeine from the coffee beans. The beans are soaked in a bath of supercritical carbon dioxide at very high pressure for about 10 hours. The carbon dioxide is like a magnet and attracts all the caffeine molecules. When the pressure is reduced the CO2 evaporates. This process has the advantage of not using any harmful substances and does not chemically affect the proteins or carbohydrates of the bean.
Grinding
The single most important thing to remember is that you should only grind the amount fo beans that you plan to use for immediate brewing. Once your coffee is ground, the flavourful oils contained inside are subjected to air, which decomposes the beans. It literally begins to lose flavour the second the beans hit the burrs in the grinder. Different methods of brewing will require different modes of grinding. As a rule, most people use a drip-style coffee brewer at home. For this style, ground coffee should resemble the consistency of granulated sugar. A full pot of coffee should not take more than four to six minutes for the brew cycle to complete. If it takes longer, you may want to grind the coffee coarser. For the French Press it is important that the grind is very coarse, too fine a grind will cause the final brew to be bitter due to over-extraction. The grind is too fine when it is difficult to push the plunger down into the pot.
Storage
Once roasted, coffee beans must be stored properly to preserve the fresh taste of the bean. Never store your coffee beans in the refrigerator or freezer. Coffee has a funny habit of absorbing the flavours and aromas of foods around it. Our recommendation is to store your beans in a clean, dry, airtight container, which should be kept in a cool, dark place (cabinet, pantry, etc.).
dosage tip
Making coffee using a drip brewer or a French Press – use 1 heaped tablespoon of coffee per 180ml water used.
Home espresso machine – use 7-8 grams of coffee for a single shot, and 14-16 grams for a double shot. On a final note, it is important to use cold, filtered water! It represents 98% of a brewed cup of coffee, and truly makes a difference in the taste of a given bean.
