There are about 25 major species of coffea (coffee plant) within the Rubiaceae family, but only two are commercially imported to the coffee industry. They are coffea Arabica and coffea Canephora (commonly known as Robusta) Arabica beans represent 65% of world production, with Robusta representing 35%.

Coffee can only grow between 25 degrees north and 25 degrees south of the equator ( or between the tropics of Cancer and Capricorn) with Arabica growing in soil more than 600m above sea level and Robusta growing from sea level to 600m.

Nearly all speciality coffee is 100% Arabica with Robusta beans being used for instant soluble coffee.

Coffee plants take 3–4 years to mature before they can be harvested. After that they have a production life of 20–30 years.

The Arabica cherries ripen after 6 – 8 months and Robusta ripens between 9–11 months.

The cherries are then harvested and processed. On average each picker gathers between 100-200 pounds of cherries a day. Of this only 20% is bean. Coffee is shipped out of farms in 100-130 pound bags; therefore it will take one picker 3-6 days to fill one bag.

Brazil, the largest producer of coffee produces some 27 million bags of coffee a year (approximately 1/3 of all coffee produced in the world).

There are two main methods for processing cherries - wet and dry. The dry method involves spreading out the harvested beans in the sun to dry. This takes 7-10 days. The wet method involves passing the cherries through a pulping machine to separate the beans from the cherries. The beans are then stored in a fermentation tank for 12-48 hours to separate the protective layers. The beans are then spread out in the sun to dry for 7 -15 days.

The beans then go to a local cooperative to be ‘hulled’, which is the process of removing the outer skins from the bean.

The beans are then graded and sorted by size and quality, and then shipped out to the roasting companies.

The coffee roasting process differs vastly, depending on he company’s method to the variety of bean being roasted, and type of drink it is intended for, i.e espresso / filter etc.

When the beans start to turn brown the coffee oils (Cafeol) start to be released. This process, called pyrolosis is at the heart of the roasting, as it produces the flavour and aroma of the coffee. This is an extremely precise art, requiring years of practice. During the roasting process the beans expand by 50-80% and can lose 16% of their original weight. Once the beans reach the required colour (roast), they are usually rapidly cooled, using either water or air, to stop the roasting process. Once roasted the beans only have a week shelf life when exposed to air, so at Costa they are sealed in special airtight bags as soon as they come out of the roaster. Once ground, coffee will become stale ten times quicker than beans (as quickly as 1–2 hours).

The decaffeination process occurs at the green bean stage (before roasting). This process is often done in Germany or Switzerland where the methods have been developed. There are three main methods used to extract the caffeine.

The first method (Direct contact method) sees the beans softened by steam and then flushed by methylene chloride, a solvent that soaks through the bean to remove 97% of the caffeine. After this the beans are then steamed for the second time followed by a drying process.

The second method (Indirect contact method) the beans are soaked in water. Gradually the water dissolves the caffeine and some of the other coffee flavours from the bean. The beans are then separated and the water is treated with methylene chloride to remove the caffeine. The water is then heated to remove the chemicals. After this the beans are returned to the water to allow the absorption of the coffee flavours back in to the beans.

The third method (Swiss Water Process) sees the beans immersed in water for several hours until at least 97% of the caffeine is removed. The resulting solution is passed through activated charcoal or carbon filters to remove the caffeine. Then, as in other methods, the coffee elements are added to the coffee beans. This method is called the Swiss water process after the Swiss company that invented it.