Understanding Coffee

 In Articles, Introduction to Espresso

The History Of Coffee

The history and development of the beverage that we know as coffee is varied and interesting.

According to one story the effect of coffee beans on behaviour was noticed by a sheep herder named Kaldi as he tended his sheep. He noticed that the sheep became hyperactive after eating the red “cherries“ from a certain plant. He tried a few himself, and was soon as overactive as the herd. The story relates that a monk scalded him for “partaking of devil’s fruit“. However, the monks soon discovered that this fruit from the shiny green plant could help them stay awake for their prayers.

Another legend gives us the name for coffee or “mocha”. An Arabian and his followers were banished to the desert to die of starvation. In desperation, Omar and his friends boiled and ate the fruit from an unknown plant. Not only did the broth save the exiles but their survival was taken as a religious sign by the residents of the nearest town, Mocha. The plant and its beverage were named Mocha to honour this event.

The Galla tribe from Ethiopia used coffee, but not as a drink. They wrapped the beans in animal fat as their source of nutrition while on raiding parties. The Turks were the first country to adopt it as a drink, often adding spices such as clove, cinnamon, cardamom and anise to the brew.

Coffee was introduced much later to countries beyond Arabia. They guarded its secret like top military plans. Transportation of the plant out of the Muslem nations was forbidden by the government. The spread of coffee started illegally. An Arab named Baba Budan smuggled beans to some mountains near Mysore, India and started a farm there. Early last century the descendants of those original plants were found still growing fruitfully in the region.

Coffee was believed by some Christians to be the devil’s drink. Pope Vincent III heard this and decided to taste it before he banished it. He enjoyed it so much he baptised it, saying “coffee is so delicious it would be a pity to let the infidels have exclusive use of it“.

Coffee today is grown and enjoyed worldwide, and is one of the few crops that small farmers in the third world countries can profitably export. In the worldwide marketplace coffee ranks alongside oil, steel and grain and grows as an exportable raw material. Many prime coffee producing nations are almost entirely dependent on the export of coffee for their material wealth.

The Coffee Plant

The coffee plant is the first link in the long chain to a cup of espresso.

Coffee beans begin as waxy, white, strongly perfumed flowers (of the Jasmine family) which covers the shrubs branches in clusters. The fruit, known as cherries, begins as small, green berries which grow larger and turn bright red as they mature. Within each cherry there are two seeds. The coffee we drink is made from the dried and roasted seeds of these ripe berries.

Coffee belongs to the Rubiaceae family of which there are two major species commonly known as Arabica and Robusta. Both grow in a belt around the world between the Tropics of Cancer and Capricorn.

Arabica prefers altitudes above 600 metres while Robusta grows on the lower slopes. Due to higher altitudes and lower temperatures Arabica is a delicate plant that requires intensive cultivation and is generally handpicked due to the hillside terrain. The beans are denser and far more intense in flavour that their lower grown siblings.

Robusta, as the name suggests, is more resistant to the tropical climate and its accompanying diseases and parasites. It’s growth cycle is shorter. It therefore arrives on the market at a much lower price than Arabica. Robusta is the base for most instant coffees.

Arabica constitutes about three quarters of the worlds total production and is the source of the worlds great coffees.

Arabica coffee has a very pronounced aroma, is mild, well rounded, slightly acidic and often features a hint of chocolate. It produces a hazelnut brown crema with a pleasing touch of bitterness.

Robusta coffee is more astringent, not very aromatic and much more bitter. Its crema is brownish grey.

The caffeine content of Robusta is about twice as much as Arabica.

The two most important coffee markets are New York (Arabica) and London (Robusta).

Processing – Wet & Dry Methods

In the tropics, the seasons do not follow the same sequence as in the temperate climates. The flowering and ripening cycle begins after every rainy period. For this reason, there are nearly always berries and flowers on the same coffee plant.

Coffee beans must be removed from the fruit and dried before they can be roasted. This can be done in two ways, known as the dry and wet methods. When the process is complete the unroasted coffee beans are known as green coffee.

THE DRY METHOD – This is the oldest, simplest and requires little machinery. Dry processing produces what are called natural coffees.

The method involves drying the whole cherry. The cherries are sorted and cleaned by winnowing or flotation in washing channels. They are spread out in the sun on concrete patios or trestles. As the cherries dry they are raked and turned to ensure even drying. This can take up to four weeks.

The drying is very important to the quality of the coffee. An over-dried coffee will become brittle and produce too many broken beans. Coffee which is too moist is prone to attack from fungi and bacteria.

The dry method is used for a large proportion of Arabica coffees and almost all Robusta coffees.

THE WET METHOD – This method requires the use of specific equipment and substantial quantities of water making it the more expensive option. This method ensures the intrinsic qualities of the coffee beans are better preserved, therefore producing a better product which commands higher prices. These coffees are called washed coffees.

The cherries are sorted then de-pulped, separating the pulp of the fruit from the beans before the drying stage. Any residue of pulp is removed completely from the beans in fermentation tanks where it is washed away. This takes between 24 and 36 hours.

After fermentation the coffee is thoroughly washed with clean water. The beans, still wrapped in a protective film called the “parchment“ are then sun dried, machine dried or a combination of both.

Coffee produced by this process are some of the finest in the world and almost always Arabica.

Washed coffees are brighter with cleaner more consistent flavours. Dry processed coffees are generally heavier bodied and more variable in flavour.

Blending & Roasting

Producers of green coffee often provide sketchy information about quality, so before buying a consignment of coffee, tasting samples from various sources are indispensable.

The blend is roasted slowly to avoid any big surges in temperature. This allows every bean to develop its full flavour while gradually taking on its typical brown colouring. The depth of flavour and aroma is entirely dependent on the duration and temperature of the roasting period.

Further vital factors are air cooling the roasted beans and immediate packaging to avoid oxidation and to guarantee that the blend loses none of its bouquet.

The best coffee blends are produced by combining several types of coffee beans from different parts of the world. The various properties and characteristics combine to balance the taste and aromas.

Blends of pure Arabica are milder and more aromatic than blends of Arabica and Robusta which have more body and stronger flavour.

Grinding & Dosing

Roasted coffee is sold in beans so as not to alter its taste and to maintain its fragrance. Considering that espresso means “made on the spot“ the grinding of each dose must occur immediately prior to the actual brewing of the coffee. The tool used for this operation is the grinder.

The most important part of this machine are the blades. There are two discs, one rotates while the other, mounted on a toothed ring nut, controls the degree of grinding.

There are two types of blades. Flat grinder blades and conical grinder blades.

There are two reasons why the conical blades are normally preferred. Up to 1000kg of coffee can be ground without signs of wear, while flat blades must be changed after 400kg. Conical blades avoid overheating as the rotating speed is lower.

As soon as blades show signs of wear it is essential they are changed.

The degree of grinding is directly related to the extraction time of the espresso. If the grind is optimal, an espresso is extracted between 20 to 30 seconds. If the extraction time is lower than that, the grind is too course. An extraction time exceeding 30 seconds indicates that the grind is too fine.

Another main component of the grinder is the doser. This devise determines the exact dose of coffee needed for an espresso.

Its design is such that the volume of coffee released is measured. The weight of the dose varies depending on the characteristics of the coffee used.

The Language Of Coffee

Arabica

is the quality bean, has half the caffeine of Robusta, grows at higher altitudes, matures slowly and is handpicked.

Arabica

a bartender trained in espresso preparation.

Barista

is the quality bean, has half the caffeine of Robusta, grows at higher altitudes, matures slowly and is handpicked.

Bean Hopper

stores the coffee beans prior to grinding. A tinted hopper preserves the beans from light. The hopper should have no more beans than necessary for service that day.

Blank Filter

used to clean the diffuser by fitting the group handle with a blank filter and back flushing with water several times a day. Daily the blank filter should be used with Mulclean detergent

Caffeine

is a compound found naturally in coffee and more than 60 other plants. It is odourless, slightly bitter tasting solid that dissolves easily in water or alcohol.

Cake

the spent coffee from the group handle, should knock out in a firm almost dry condition after extraction. This is called the cake.

Crema

the crema on an espresso should be a 0.03 inch thick, rich, hazelnut coloured foam.

Decaffeination

whatever method of decaffeination is used, the decaffeinated green coffee must contain less than 0.1% caffeine to comply to EEC regulations. This corresponds to about 3mg of caffeine in a cup of decaffeinated coffee.

Dry Processing

coffee processed by removing the husk or fruit after the coffee berries have been dried. This process produces “natural“ coffees.

Electro Pump

This devise is used to raise the mains water pressure up to 9 bar.

Espresso

is made to order from freshly ground beans. The perfect espresso is 7 grams of coffee extracted between 20-30 seconds, no more than 40ml, served in a warm cup.

Grinder/ Doser

the machine used to grind the coffee beans prior to extracting a cup of coffee.

Group Handle

portable coffee filter to be fitted with a single, double or triple brewing basket in preparation of an espresso coffee.

Group Head

is the part of the machine from which hot water is dispersed through the group handle.

Heating System

there is a electric element immersed in the boiler water which heats the water and produces steam.

Pressure Gauges

indicate the boiler pressure and the working pressure of the pump.

Pressure Sensor

controls the pressure and the activation of the heating system to maintain the boiler water at a constant temperature

Robusta

is grown at lower altitudes, has a quicker growth cycle and is therefore cheaper to process and used mainly as bases for instant coffees.

Steam Wand

delivers steam to froth the milk necessary when making cappuccino, to heat up water or prepare hot chocolate.

Syrup de Gomme

sugar syrup

Tamper

tamping compacts the coffee ensuring water pressure is evenly distributed. Most grinder-dosers have a tamper attached to the body, however, a manual tamper will achieve better results.

Water Level Gauge

Indicates the water level in the boiler.

Water Tap

Supplies hot water for Tea.

Wet Processing

coffee processed by removing the skin and pulp from the bean while the coffee berry is still moist. Most of the worlds great Arabica coffees are processed this way and are called washed coffees.

 

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