The Coffee Tree
The coffee "tree" is actually a variety of tropical evergreen shrub. There are three species of coffee "tree", all three are of African origin, arabica, liberica and robusta. Arabica originated in Ethiopia and is best suited to higher altitudes from 2000 to 6500 feet. Liberica originated in West Africa and robusta originated in the Congo, both do better below 2000 feet. Liberica and robusta trees are hardy and do well in forest environments and require less maintenance than arabicas. Liberica and robusta trees also produce higher yields, but the coffee they produce tends to have a harsh flavor in comparison to arabicas and their caffeine content can be as much as 50% higher. Most of the instant and tinned coffees at your local grocers is produced from the these less expensive liberica and robusta coffees. Gourmet coffees on the other hand rely almost exclusively on the more expensive arabicas.
The best growing conditions are in a temperature range of 65 degrees Fahrenheit to 75 degrees Fahrenheit at an altitude best suited to the species of coffee tree (liberica and robusta at altitudes below 2000 feet and arabicas between 2000 and 6500 feet). Rainfall should be plentiful and the weather should switch between heavy rainfall and sunshine to bring the berries to full maturity. The type of soil is not too important but good drainage is a must.
The coffee tree's fruit does not all ripen at one time. In fact it will have blossoms and berries (or cherries if you prefer) in various stages of ripening. This fact complicates the harvesting of coffee since only the ripe berries can be picked. If the berries are left too long their beans will spoil, and the berries cannot be picked when green since they will not ripen once picked. This fact requires that the pickers of quality coffees return to each tree numerous times to harvest its berries. Since each tree only yields about two pounds of beans per year, this equates to a great deal of labor for every cup of coffee that you drink.
The growers of less expensive coffees often use less labor intensive methods to harvest their coffees. These methods produce poor grade, harsh flavored coffees. For instance some growers in Brazil use a method that strips the whole branch of the tree at once, leaves, flowers, green and overripe berries. This is very damaging to the trees and it takes some years for them to recover. Another less damaging method is used in Africa, there they will shake the trees causing the berries to drop to the ground where they can be easily picked up.
The coffee tree does not begin to produce its full yield until its sixth year and will continue produce for about ten years. The tree if left alone will grow to a height of between 16 and 40 feet. In most coffee plantations the trees are kept at a manageable six feet to get the best yield and to make it easy to harvest.
Since there are only three main species of coffee tree, you might wonder why there are so many different varieties of beans offered for sale? This can be attributed to the wide variety of climates, altitudes, soils and amount of rainfall that the coffee trees grow in. Although coffee trees grow in only tropical and sub-tropical areas, these areas have a wide range of climatic differences. Coffee trees grow in the highlands of Central America where the temperatures are cooler and there is a great deal of wind and fog. They also grow in the hot, steamy lowland jungles of Africa and in the variable conditions of the Caribbean. All of these areas produce beans with different characteristics.
Processing the Harvested Beans
Preparing the harvested beans for market requires that the fruit, inner parchment, and outer hull of the bean be removed. These outer layers are removed by either the wet method or the dry method. In the wet method, the beans are mechanically de-pulped and then soaked in fermentation tanks for up to three days. These "washed" coffees have characteristically higher acidity and sharper flavor than dry processed beans. In the dry method, the berries are either sun-dried or machine dried with the outer fruit intact. After drying they are de-hulled mechanically, producing beans that are characteristically lower in acidity, yet fuller-bodied and more complex in flavor than washed coffees. The coffees produced by the dry method are referred to as "naturals" and have the advantage of ageing better than those produced by the wet method.
The availability of abundant supplies of clean, fresh water often determines which processing method the coffee producer will use. In Central and South America, the wet method is predominately used while in East Africa and Yemen, the dry method is used. Even though the wet method is considered to be superior by many experts because it tends to produce a more flavor-consistent bean, some excellent coffees are being produced by the dry method as well.
After having gone through either of the above methods the coffees are sized, sorted and graded by hand.
Coffee is produced and exported by a large number of countries. Each country has its own system for classifying the over one hundred types of coffee. But there are some basic groups and classifications that are used.
The three basic groups of coffees are:
Milds are all of the arabicas grown outside of Brazil. These coffees include the premium or quality coffees that are used by the gourmet coffee industry. The term "mild" does not necessarily refer to the taste of the coffee, some of these have a bitter or acidic flavor.
Brazils are all of the coffees grown in Brazil. These are almost exclusively made up of arabicas. The Brazils are for the most part the less expensive type used for tinned and instant coffees.
Robustas are African grown coffees that are also low quality and used for tinned and instant coffees. There are also many secondary classifications that are used such as the type of plant (Excelsa, Bourbon, Maragogype), processing method (wet or dry), plant species (arabica, liberica, robusta) and so on.
What is Caffeine?
Molecule of caffeine - ever seen it before?
CH3 | N / \ N----C C==O || || | || || | CH C N--CH3 \ / \ / N C | || CH3 O
The major pharmacologically active ingredient in coffee is the central nervous system stimulant, caffeine, known chemically as 1,3,7-trimethylxanthine. The dimethylxanthine derivatives, theophylline and theobromine, are also found in a variety of plants.
Caffeine occurs naturally in the leaves, seeds or fruit of more than 60 plant species, of which cocoa-beans, tea, coffee, cola and guarana are the most well known. Caffeine is also added to many popular carbonated drinks, and is a component of a number of pharmacological preparations and over-the-counter medications including analgesics (where caffeine acts as an adjuvant), diet aids, and cold/flu remedies. (Caffeine added to a food or drink must, by law, be included in the ingredients list). In addition, both caffeine and theophylline have bronchodilatory properties, and are used in the treatment of neonatal apnoea (inability of the newborn to breath properly).
Following consumption, caffeine is readily absorbed into the blood and body tissues, and has a half-life of approximately four hours, although estimates for the half-life vary between two and ten hours. Caffeine does not accumulate in the body, being rapidly metabolised and excreted. Smokers break down caffeine more quickly than non-smokers (so the effects do not last so long), while pregnancy tends to slow down the rate at which caffeine is broken down, particularly during the last months. Women taking the contraceptive pill also metabolise caffeine more slowly.
UNDERSTANDING COFFEE, CAFFEINE AND WOMEN'S HEALTH
COFFEE SCIENCE ARCHIVES
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UNDERSTANDING COFFEE, CAFFEINE
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