Each coffee cherry usually contains two coffee beans with their flat sides nestling against each other.

The coffee beans inside the cherry are green in colour, their natural state as a seed.

Some coffee cherries, around 5%, contain only one coffee bean, this bean is referred to as a Peaberry.

As this Peaberry doesn’t have another coffee bean to push against it is round in shape instead of having one flat side.

The coffee beans contain between 0.8% and 2.5% caffeine, a natural stimulant which makes coffee a very popular drink and the green coffee beans the world’s second valuable traded commodity, behind only petroleum.

Coffee Bean (Roasted)

The brown coffee bean we are all used to seening in our local coffee shop is actually the final product from the coffee roasting process.

The green beans are roasted in a large heated drum for between 8-15 minutes until brown in colour and are ready to send to coffee shops, supermarkets and our homes.

There are more than 90 species of coffee plant but only a portion of these are used to make the coffee drink.

Coffee Plants

Coffee plants used to make the coffee drink are usually grown in tropical and sub-tropical countries on large farms or plantations.

These tropical plants are small trees that grow to a height of 3-4.5 meters (10-15 feet) and live for 50-70 years on average.
Coffee plants leaves are broad, waxy green and thickly cover the branches.
They bear fruit, coffee cherries,  after 3-5 years and then for the rest of their lifespan.
They also produce sweet, jasmine like flowers in huge quantities.

Coffee Cherries on a Coffee Plant

There are 2 main types of coffee plant grown and harvested around the world, Coffea Arabica and Coffea Robusta.

Robusta is grown at lower elevations than Arabica and  produces a greater yield of coffee beans per plant.
It is also a more robust plant, more resistant to disease and bad weather.

Robusta coffee contains twice as much caffeine, which gives coffee its bitter taste, as Arabica.
As such Robusta is classed as a lower quality coffee than Arabica, often being used for instant coffee, especially due to its lower production costs.

Arabica is grown at higher elevations often on the side of hills and mountains and makes for all the worlds best coffees.
The lower caffeine content gives a smoother taste preferred the world over.
Arabica needs plenty of sun and water with low pH soil and is often grown in volcanic regions as the soil there is perfect for Arabica growth.

Arabica contributes around 75% of all the worlds 8 million or so tons of harvested coffee each year.

Arabica coffee plant

]]> http://www.coffee-machine.org/the-coffee-plant/feed/ 2 http://www.coffee-machine.org/coffee-growing-and-harvesting/ http://www.coffee-machine.org/coffee-growing-and-harvesting/#comments Tue, 24 Mar 2009 12:30:20 +0000 Coffee Machine http://www.coffee-machine.org/?p=113 Coffee Growing

To grow coffee you need three main things.

• Moderate rainfall, too much or too little will ruin the crop.
• A frost free climate.
• Lots of sunshine.

Though the conditions can vary, producing different types of coffee, these main requirement need to be met.

Coffee is produced in various regions across the world, these can be grouped as the Americas, Africa and Arabia, and Indonesia.

Inside of these three regions the coffee plant grows in around 80 different countries with Brazil begin the largest grower.

Coffee Producing Countries

In these countries, coffee can grow at anywhere from sea level to 6,000 feet (1,828 meters) in lots of different types of soil and local climates.

The higher quality coffees need more exacting conditions however.
These coffees need to be at high altitudes, between 4,000 to 6,000 feet (1,219 to 1,828 meters) and only grow in select mountainous regions between the Tropic of Capricorn and the Tropic of Cancer.
They also need around 80 inches (203cm) of rainfall annually, and the rainy and dry seasons must come in set periods.
Cloud and mist needs to present on regular intervals to block overexposure to the sun.
The soil must be very fertile and is often volcanic as this is rich in nutrients and generally considered the best type of soil for crowing crops.
Finally the average temperature must be held around 60-70°F(15-21°C) which by tropical standards is quite cool.
This lower temperature means the growing period is longer, which leads to denser crops and a more intense flavour.

Coffee grown outside of this area and at lower altitude still produces good coffee but tends to have  a more simple taste without the intense flavour of the higher grown beans.

Coffee Harvesting

The coffee tree’s cherries are harvested individually by hand.
This process allows the coffee to be collected when its is ripe and means it is handled with care.
The average coffee tree will be returned to several times over a harvest as all the cherries do not ripen at the same time.

Once collected from the trees the next process is to remove the seed ‘the coffee bean’ from inside of the cherry.

Removing the bean from the cherry involves removing four outer layers.

These are the tough outer layer, the sticky pulp layer, a stiff parchment casing and finally the thin silverskin that wraps around the bean.

Cross-section of a Coffee Cherry

There are two methods of removing the coffee bean, the wet and dry methods.

Which one is used depends mainly on the availability of fresh clean water and has a significant impact on the flavour of the coffee.

The wet method involves removing the bean from the pulp in purpose built machinery.
After removing the bean from the pulp, it is then placed in a fermentation tank where water is added to start the fermentation process.
This process usually last between 12 and 36 hours, but must not be allowed to go over this time as the ripen fruit can soon become rotten.
Once fermentation is complete the beans are washed free from the remaining pulp then left to dry.
The drying is done on large patios and the beans are raked several times a day to ensure the beans dry evenly.

The dry method is a lot more simple but doesn’t give the clean even taste associated with the wet method.
The dry method simply involves leaving the coffee cherries out in the sun for several weeks until they are dry.
The beans are then simply separated from the dried cherry.

Whichever method is used the next stage is to remove the parchment and the silverskin from the bean by milling.
Once done they are sorted by size to make sure of even roasting and any foreign materials, twigs, stones and so on are removed.
These beans are ready to be shipped to roasters and retailers in their now ready ‘green coffee’ state.