Understanding Coffee

"BLACK AS THE DEVIL, HOT AS HELL, PURE AS AN ANGEL, SWEET AS LOVE.” - CHARLES MAURICE DE TALLEYRAND

 

TYPES OF COFFEE

There are two main species of bean, robusta and arabica; both thrive in equatorial regions.

Robusta

Growing at lower altitudes from sea level to 1,000 metres, robusta has a high yield per plant and high caffeine content, and it accounts for about 30% of world production.

Arabica

Growing at 1000 metres and above, Arabica is widely recognized to be superior to robusta. Accounting for about 70% of world production, Arabica has a delicate acidic flavour, and a refined aroma.

 

ROASTING

Roasting is the process in which the coffee beans are cooked; sugars and carbohydrates in the coffee beans are emulsified and caramelized to extract the coffee oil. The degree of roasting leads to different level of coffee oil extracted within the beans which ultimately brings out the different aromas and tastes of the coffee. The degree of roasting is usually categorised into:

Light

Light brown to cinnamon colour with low body and light acidity. The bean is dry and generally is too light and does not allow the flavour to develop fully.

Medium to Light

Medium light brown colour with bright acidity. The bean is still dry at this level.

Medium

Medium brown colour with balanced acidity. The bean is more potent and is mostly dry.

Medium to Dark

Rich brown colour with small droplets of oil appearing on the surface. The acidity is slowly diminished and bean is most potent.

Dark

Deep brownish/black colour with spots of oil or is completely oily. Dominated by bittersweet with less acidic.

Very Dark

Develops oil on the bean surface. The bean will generally have a bitter and smoky or burnt taste. The amount of caffeine is substantially decreased.

 

GRINDING

Grinding is done after roasting of the beans, and just before brewing your coffee. The grind of the coffee is important to its taste and aroma. The coarseness of the grind determines how fast the water passes through during brewing. Look for a grinder that grinds the beans consistently – a burr grinder is better for this than a blade grinder. Grinding tips:

French Press: Grind the coffee to large size grind.
Drip Brewing: Grind to a medium sized grind. 
Espresso: Grand to a fine sized grind.

 

BREWING

Coffee brewing is made with coffee grounds, with an ideal water temperature between 92°C and 96°C. Brewing methods can be categorised into four main groups:

Boiling

The earliest and easiest method of making coffee; simply place water together with finely ground coffee in a coffee making instrument and allow it to cool as the grounds sink to the bottom. This brewing method is predominantly used in making Turkish coffee.

Pressure

One of the popular brewing methods used in an espresso coffee maker by forcing pressurised hot water through the coffee grounds. Moka pot (a three- chamber design) and vacuum brewer (a two-chamber design) are the types of coffee making instrument applying this water vapouring technique.

Gravity

Commonly used in America, drip brewing or filter brewing is simply letting hot water drips onto coffee grounds that are held in a coffee filter. Though the result of the coffee is weaker than that of espresso, it is easy to control the coffee’s strength. Strength varies according to the ratio of water to coffee and the fineness of the grind, but is typically weaker than espresso.

Steeping

A cafetière or French press is a tall, narrow glass cylinder with a plunger that includes a filter. The coffee and hot water are combined in the cylinder before the plunger is depressed to isolate the coffee at the top ready to be drunk. This style is considered by many coffee experts to be the ideal way to prepare fine coffee at home.

 

REGIONAL VARIATIONS

Adding coffees from different sources helps add the various characteristics needed for suitable complexity of flavour. As a rule of thumb:

To add body, acidity and flavour:

Coffee from Colombia, Costa Rica, Guatemala and Venezuela are used.

To add complexity and brightness:

Coffee from Ethiopia, Kenya, Yemen, Zimbabwe and Zambia are used.

To add richness and body:

Coffee from Sumatra, Sulawesi, Java, East Timor, New Guinea and Ethiopia are used.

 

TIPS FOR A GREAT CUP

Freeshness

Coffee should be bought as fresh as possible and should not keep for more than 4 weeks. The enemies of fresh roasted coffee are direct sunlight, heat and moisture, so store the coffee in an airtight container at a cool, dry and dark place.

Grind

Be certain that the grind used is right for the type of brewing you are using and avoid over-steeping your coffee.

Water

Water quality plays an important role. It is preferred to use filtered or bottled water. If tap water is used, let the water runs for few seconds first.

Temperature

A water temperature of 92°C to 96°C is preferred. Avoid boiling the coffee, as this will scald the beans and spoil the flavour.

Proportion

The proportion of coffee used depends on the strength you want. Try various combinations; too much water will dilute the flavour while too little water will result in an over-powering flavour.