Coffee As A Plant
Two main species of coffee are cultivated. Coffea arabica, known as Arabica coffee, accounts for 75-80 percent of the world’s production.
Coffea canephora, known as Robusta coffee which makes up the remaining 20 percent and differs from the Arabica coffees in terms of taste. Robusta coffee has an inferior taste with higher caffeine content. Both the Robusta and Arabica coffee plants can grow to heights of 10 meters left unchecked.
Robusta plants are capable of growing below the necessary 1800 feet above sea level for Arabica coffee. Robusta also tends to have greater plant disease resistance and produces a higher yield than Arabica trees.
Arabica plants are self pollinating whereas Robusta plants require cross pollination in order to produce coffee cherries. Coffee cherries grow along what is called the “axils” of the branch which is in between the leaves of the plant.
The Espresso Machine
Simply put, espresso machines force water through ground coffee in order to emulsify the soluble components of the coffee. This occurs through the use of a water heating source (Boiler) and a pump to aid in the passing of water through the coffee grounds.
These espresso machines passed water over a heated metal reticulation system that heats the water almost instantly, and is commonly found in home espresso machines.
This type of coffee machine utilises a boiler filled with water and heated by an element. This type of boiler is commonly found in home espresso machines and is a considerably cheaper to purchase than the heat exchanger models and multi boiler models.
The heat exchanger is a semi commercial or commercial application for espresso machines. This system has a large usually copper/brass boiler which heats the water for steaming milk and simultaneously providing hot water for espresso extraction. This method supersedes the single boiler concept by of passing water through the boiler inside a pipe to heat water for extraction. The water inside the boiler therefore is not reheated water which provides a better quality water source for espresso extraction.
The multiboiler concept uses multiple boilers inside the same machine, one of which is dedicated solely to the heating of water for espresso extraction and another boiler which provides steam for frothing milk and hot water.
Stove Top Espresso
The stovetop espresso functions by way of heating water (A) which when approaches boiling point pass through ground coffee (B) and the water carries through to the top part of the espresso pot © as a brewed coffee.
The plunger coffee is made by putting an amount of coarsely ground coffee into the glass beaker and adding nearly boiling water. The coffee is allowed to steep in the water for approximately 3 -4 minutes before a filter layer in plunged through the brew to separate the coffee from the water before pouring and drinking.
The Paper and permanent filter coffee makers use a boiler to heat the water and raise it above a conical or V – shaped filter where it passes through ground coffee. A paper filter differes from the permanent filter as the permanent filter is often a gold plated metal that is reusable. The paper filter is used once and is then discarded.
Turkish coffee is made in what is called an ibrik or a jezzve. This is a style that requires the user to finely grind the coffee, in some culture the addition of spices is common and then add cold water and bring the water almost to the boil. This process is repeated while the coffee is stirred to achieve the preferred brew strength. In regards to the fineness of grind this style of coffee making defies the usual rule whereby the longer the brew time the coarser the grind of coffee.
The percolator coffee maker is less common these days and functioned by way of water that is approaching the boil passes up through a central funnel in the coffee maker and passes through the coffee in a basket by gravity back into the water in the base of the pot. The desired brew strength is achieved by allowing the pot to brew for a longer period of time.
The storage of coffee is something that has been a constant source of debate. The best methodology to follow is to buy coffee freshly roasted and in beans, the coffee should then be ground when coffee is to be made. The beans or ground coffee should be kept in an airtight container out of light. Exposure to light, air and moisture will quickly make coffee go stale. Ideally, if freshly roasted coffee is bought for consumption on a weekly basis, then most matters of degradation and lose of flavour can be easily avoided.
There are many ways to define specialty coffee, more than anything it is a product of quality first and foremost. The Cup of Excellence™ defines specialty coffee as: “Coffees of this exemplary quality are very rare. These coffees are perfectly ripe, carefully picked with well developed body, pleasant aroma and a lively sweetness that only extremely high quality specialty coffees contain. Each winning coffee has its own flavor signature from the earth where it grows and all have been handcrafted in such a way as to enhance these unique characteristics.”
A key aspect of specialty coffee is the recognition of origin and the awareness of the factors that must be present that deliver a quality cup of coffee. These factors take into account three main areas Producers/Growers, Coffee Roasters and Baristas.