Coffee from A to Z
Rubiacee family, Coffea genus.
Rubiacee family, Coffea genus. This is the correct scientific definition of the coffee tree. The two most important and well-known species of the family belong to: Arabica and Canephora (more commonly known as Robusta).
Arabica
Undoubtedly the most popular species, from whose cultivation we get about three-quarters of the world's coffee production. The tree's height varies between 10' and 16', which when grown on the plantation drops to 6.5' - 10'. Its trunk is smooth and straight with long, slender branches and lance-shaped, leathery leaves. Two seeds are contained in the bottom part of the cherry blossom, divided in two, from which we get the coffee beans. It is a species that easily adapts to different environmental conditions, and that prefers the changes of season. The Arabica can grow at an altitude of between 3000 and 7000 feet, where the temperature ranges between 59° and 75°F. The green Arabica bean has an aromatic richness and a range of precursors higher in terpenes, with a lower quantity of pyrazines and furans. It also has the greatest quantity of cyclotene, 5-hydroxymaltol and phurphuril pirrols.
Robusta
A widespread species that perhaps is not as superior but is certainly hardier. In its wild state its height varies from 23' to 43'; it has fine, elliptical-shaped leaves, and its round fruit is particularly impressive. Unlike the Arabica, the Robusta is grown at a lower altitude - between 650 and 2000 feet - precisely because it does not like the temperature range of high altitudes and is fond of constant temperatures between 75° and 85°F. Rather inflexible from the climatic viewpoint, the Robusta is however less subject to disease and therefore requires less care. Robusta is richer in phenols, alkylpirrols, caffeine (1.6-3.2%, and even more) and other compounds. After roasting, the difference in aroma and taste are brought to the forefront.
Growing Coffee
The coffee tree can be propagated by seeding or by cutting. In the first case the fruit is harvested when it is completely ripe, then its flesh is stripped off and the best specimens are selected by hand with the help of water (the seeds that float when placed in water are certainly of poor quality). Then they are placed in wooden cases and covered with soil, humus and large leaves awaiting the birth of the new plants. In the second case, a small branch of the adult tree is placed in the ground. Arranged singly in a nursery, the future coffee tree develops for about one year before being transplanted to a plantation where it will start to bear fruit following another three years of acclimatization. A mature coffee plant will continue to produce its maximum yield for an additional 40 years.
Harvesting: Picking or Stripping
Harvesting is unquestionably one of the most expensive components of the coffee growing process. There are several harvesting techniques that ensure different levels of quality. Due to the extended growing season in the tropics, coffee trees will often flower multiple times during the growing season, thus producing ripe and unripe cherries on the same branches. The picking harvesting method is very precise because only the red, ripe cherries are selected and picked, but it does require having to go through the rows of the same trees several times over several weeks. While it is expensive and time consuming, it produces a very high quality yield. The stripping method is a mechanical process that is less costly in terms of time and money, but since the entire branch is stripped at one time of both ripe and unripe cherries, the result is a lower quality harvest.
Processing: Dry or Wet Method
There are two major methods of processing a coffee cherry into a coffee bean; a dry method and a wet method. Both have advantages and disadvantages in their respective processes. The method used to process coffee beans, is typically determined by geographical location and preference of plantation owners.
The dry process is relatively simple and is used in areas where water and energy are precious resources, such as Africa. The coffee cherries are dried naturally under the sun on huge patios. The cherries are spread evenly and stirred every 4-6 hours to rotate them for a consistent, even drying. If electrical power is readily available, then huge driers may be used. These driers can be manufactured fairly inexpensively with an open tank, a small electric motor run though an old manual car transmission that turns stir paddles in the tank, with an electric blower/heater attached.
During the drying process the fruit of the cherries will naturally begin to ferment imparting floral or fruit like flavors to the beans. If, however, the coffee is not processed correctly, the cherries can spoil imparting a sour taste to the beans. The coffee can be sold as is with the dried skin and fruit still attached, or milled removing the outer dried bits and then cleaned leaving only the green beans.
The wet process, by contrast, is a very controlled and complex. An entire system is set up using pipes, tubes, extractors and tanks. First the cherries are sorted by weight in water tubes (heavy sink, light float) and then mechanically the fruit is stripped off, the bean is washed and sent to holding tanks. The holding tanks will hold the coffee beans where enzymes are added to begin the fermentation process to break down the mucilage. This usually takes between 36-48 hours. During this time the vat of beans is carefully observed. If the beans sit too long in the tank, they will spoil and have a sour taste.
Once the beans are ready they are washed, re-milled to remove any leftover bits, washed again and then sent to huge rotating dryers where they are dried and polished. Because the entire system is strictly controlled, the wet method produces consistently high quality coffee beans.
The wet process method is used where water is abundant, in areas such as Central and South America. Coffees processed with the wet method often have crisp, clean taste profiles, for example, Colombian, Costa Rican, or Guatemalan coffees.
Selection, Storage and Grading
After the beans have been processed and dried, they are then sorted and graded. Sorting and grading can be done many different ways, from using sizing screens, shaker tables or even a high-tech photo laser. The laser measures each bean for size and color and uses puffs of air to sort-out the beans not meeting the exact specifications.
There are top grade AA green coffee beans that command the best prices, then second, third, and so on. Most of your local coffee shop roasters and our national chains purchase only the top 1% of the highest quality, green coffee beans available.
Storing your beans to maintain freshness is the key difference between making “good“ coffee and making “great“ coffee. No matter what brewing method you choose, whole coffee beans last longer for freshness than ground coffee (2 weeks vs. 1 week). Buy only enough whole coffee beans that will last you one/two weeks and grind your beans at home when possible.
Once you have opened your original coffee bag make sure to protect your coffee against these moisture, air, heat and light by storing the coffee beans in an opaque, air-tight canister. Store your coffee in a cool dry dark place such as the pantry, or a cabinet—away from light or heat.
From the Plant to the Cup
Ristretto
The "little one" is prepared with the same amount of ground coffee as a classic espresso (7 grams), but with just under 1 fluid ounce of water, making a ristretto extra strong and intense.
Espresso
Traditionally, 7 grams of finely ground espresso beans combined with 1 ounce of water, brewed under a minimum of 9 bars of pressure. Saeco machines brew espresso using 15 bars of pressure.
Caffè Lungo
The caffè lungo is the counterpart to a ristretto: It is prepared with more water than the espresso making it a little milder. The amount of used water can be chosen according to one's personal taste.
Cappuccino
A classic cappuccino is prepared with espresso, milk and milk froth. The most delicious taste experience is created when equal amounts of the three ingredients are used.
Latte Macchiato
A big glass is filled to two thirds with hot milk, the last third is filled with milk froth (from the Milk Island or Touch2Cappuccino, for example). You can also fill the glass with a little more milk, then froth it up with the aid of a pannarello or steam tube. Then 1-2 espressos are let into the glass through the middle of the milk froth crown. For a picture-perfect latte macchiato it is necessary to let the milk and froth cool down a little before adding the espresso.
