When we hear the word “coffee”, the first thing that comes to our mind is probably a nice cup of espresso… but what’s behind that cup? What does a coffee plant look like? Where does it grow? What’s the difference between Arabica and Robusta?
To answer these and other questions, here is a little glossary that will help you discover some interesting facts (unknown to most) that lie behind that delicious cup.
Coffee Glossary: the plants
Let’s start from the beginning, i.e. the plants
Coffea: the coffee plant that belongs to the dicotyledon class of phanerogams. The coffee plant is an evergreen shrub that can grow up to ten metres high. It’s widely cultivated in tropical regions.
Drupe: this is the coffee berry. It looks very much like a large cherry. What we commonly call a “coffee bean” is actually one of the two seeds contained inside the fruit of the plant.
Bean parchment: is the film or skin surrounding the coffee seed.
Arabica: represents 75% of the world’s coffee production. Arabica coffee has a round, slightly sour taste, often with chocolate notes. The aroma is intense and the crema has a hazelnut colour tending towards red with a pleasant bitter touch. Arabica is very sensitive to heat and humidity: it grows at altitudes ranging between 900 and 2,000 metres but the higher the altitude, the better the organoleptic properties of the roasted bean. The Arabica bean has an elongated shape with an S-shaped groove; it’s green (more or less intense) with shades of blue. The amount of caffeine ranges from 1.2% to 1.7%.
Robusta: as it name suggests, is resistant to hot climates and parasites. It grows in tropical lowlands at altitudes ranging between 200 and 600 metres. Robusta coffees have a “sharper”, more astringent and bitter taste and have less aroma. The crema is brown, tending to grey. The Robusta bean is rounder with a straight groove; it’s pale green with shades of grey and the caffeine content is about 1.6% to 3.2%.
Coffee Glossary: harvesting and processing
(Harvesting by) Picking: this is the most expensive harvesting method since it’s done by hand. Only the ripe cherries are selected which means that coffee pickers have to go through the rows of plants several times.
(Harvesting by) Stripping: this is a “cruder” method: the coffee pickers slide their hands along a branch, taking all the coffee cherries. The quality of the coffee obtained from this harvesting method is lower than that by hand-picking.
(Seed extraction) Dry processing: so-called “natural coffee” is obtained through this method. The cherries are washed with water then dried in the sun. Once completely dried, the drupes are placed in a hulling machine, where the beans are cleaned.
(Seed extraction) Wet processing: This method produces “washed coffee”. The cherries are placed in tanks of water to separate the ripe ones from the unripe or dry ones. Then, they are put in a machine that extracts the seed, which is left in water for a few days before being treated and released from the pulp; finally, the seed is dried in the sun or in special dryers before being put in a hulling machine to remove the parchment.
Roasting: is where the raw coffee beans are roasted at high temperatures (200-220°C). The coffee sugars caramelise and the cellulose carbonises. This gives the bean its typical colour and forms volatile organic compounds which give us that delicious, roasted coffee aroma.
Roasted beans increase their volume by approximately 30%, whereas the weight decreases as the water content evaporates. Roasted coffee beans have a bitter taste, they are friable and are easily ground.