Different Types of Coffee
Four Basic Methods of Brewing Coffee
The different methods of making coffee can be divided into four basic types:
- Filtering by Gravity
- Pressure Percolation
When Did People Start Drinking Coffee
For most people today coffee is an integral part of their lives. Whether it's that first cup of java that you prepare in your kitchen, half asleep, hoping it will wake you up enough to drag yourself to work, the Starbucks skinny latte you grab on your way to the office, or the coffee you drink while meeting with friends over a weekend, it is hard to imagine life without it. But how did people get into the habit of drinking it, and where did all the types of coffee we enjoy today originate?
Coffee is prepared from the roasted seeds of the berries (also called cherries) of shrubs from the genus Coffea. The two species that are used today are arabica and robusta, with Arabica being generally considered superior.
It is generally agreed that the wild coffee plant was originally found in Ehtiopia in Africa. Legend has it that the invigorating effects of the beans were first noticed by an Ethiopian goatherd, who noticed that his goats were particularly frisky after eating the cherries of this particular bush. The story is very amusing, although it is most probably not true.
To make coffee the beans have to be roasted first, to develop their flavour. At about 200oC an aromatic oil known as caffeol develops in the beans, and it is this that gives coffee most of its flavour.
Finally the beans are ground, different preparation methods require different degrees of grind.
Then comes the method of brewing the coffee, using hot water to extract caffeine and aroma from the powdered beans. It is here that different cultures developed their own methods, to produce very different types of coffee.
A cheap solution if you want to try your hand at making Turkish/Arabic coffee
Turkish or Arabic Coffee
The first reliable records of coffee drinking come from 15th century yemen. Coffee became very popular amongst the Arabs and in the Ottoman empire. In fact it was introduced to Central Europe after the Turks were defeated in the Battle for Vienna in 1683. The supplies of the Ottoman Empire army included large quantities of the beans.
Turkish and Arabic (and Greek) coffee is still brewed and served as it was centuries ago and prepared by boiling. The coffee is ground to an extremely fine powder, it feels like confectioner's sugar.
It is then mixed with almost boiling water, and placed on a heat source until it boils. A special pot with a long handle called cezve in Turkey and ibrik in Arabic speaking countries is used. The coffee is removed from the heat, as soon as it comes to the boil, to prevent it from boiling over. This process is repeated, usually up to three times.
Whereas boiling the coffee too long produces a bitter, stewed tasting beverage, this method does not allow that but ensures that the caffeine and aromatic oils are released into the water. It produces a lovely layer of foam. Skilful pouring is required to ensure each cup gets equal amounts of the foam, the cup with the most foam is considered the best.
The coffee is not filtered, but because of it is so finely powdered the grounds sink to the bottom of the pot to form a thick layer of sludge.
In Arab countries the coffee is flavoured with cardamom and served sweet. Bitter coffee is usually only served after a death, to symbolise the sorrow the family feels.
Coffee is an important part of Arab hospitality. It is served in tiny cups, which are refilled by the server until the guest indicates that he's had enough.
Perfect for making a single cup of coffee. Buy in bigger sizes if you need to brew coffee for more than just one person.
Steeping: The French Press and Malaysian Socks
Steeping is a relatively simple method of making coffee that produces a good brew easily without the need for sophisticated equipment.
Basically the method involves mixing ground coffee with boiling water and leaving it for a few minutes, so caffeine and aromatic oils are extracted. The next step involves separating the grounds from the liquid, so you can enjoy your hot aromatic drink without having the disgusting coffee powder stuck in your throat.
This is usually done using a French press. This is a cylindrical shaped glass pot, with a plunger, with a nylon or metal mesh filter at the bottom. Once you think the coffee has steeped inside, you push the grounds to the bottom with the plunger, so you can pour off the liquid while remains of the coffee stay at the bottom.
I really like using my French Press for making coffee. It is quick and simple. The only unpleasant bit is cleaning the French Press, with all the ground coffee at the bottom, afterwards.
You need to use fairly coarsely ground coffee in a French press. If you use fine powder, like for espresso or Turkish coffee, it will be very difficult to push the plunger in.
In Malaysia and some countries in the Caribbean a similar principle is used to trap coffee in a "sock". This is not as disgusting as it sounds, the sock is merely a muslin bag where the coffee is placed. It is then tied, and hot water is poured over it. Once the coffee has steeped sufficiently it can be removed.
In Russia, Poland and other Eastern European countries, making coffee by the steeping method is taken to an extreme of simplicity, and the problem of removing the grinds is not solved, but ignored. In Poland during my childhood, I remember adults simply placing the coffee in tall transparent glasses, pouring boiling water over it, and simply waiting for the grinds to settle.
I think they used very finely ground coffee, which helped it settle at the bottom, and I assume they just became well practised in the art of avoiding the layer of mud at the bottom of the glass.
Did You Know? The Most Expensive Coffee in the World Comes from Civet Droppings.
The most expensive coffee in the world is Kopi Luwak, selling at between $100-$600 per pound. The preparation method is highly unusual, the coffee beans are collected from the droppings of a civet, which feeds on coffee cherries.
Proponents of kopi luwak claim that the coffee is superior because the civets select the best berries to eat, and because the beans are fermented in their digestive system before processing, which makes them less acidic. Professional coffee tasters, however, generally think the civet droppings coffee is quite stale and has no body.
Coffeemakers and the Drip-Brewing Method
The drip brewing method is very popular, especially in American homes, due to the simplicity and neatness of separating the grounds from the liquid. At its simplest the coffee is placed in a filter, hot water is poured over it, and drips through the filter by gravity, extracting the coffee flavours and caffeine as it passes through it.
Of course most people now rely on electric coffee makers, that boil the water for you. Disposable paper filters are the most convenient, since they can simply be thrown away with the coffee grounds. However, you get a fuller tasting coffee if you use metallic filters, since the paper traps some of the aromatic oils that come from the coffee.
A fairly coarse grind of coffee is best for filter methods, since a fine powder would compact too much to let the water through efficiently.
One amusing consequence of the popularity of filter coffee, is that the liquid at the bottom of the pot, which passed through the filter first is stronger than the liquid at the top. This has lead to mathematical theories of how to pour the coffee, so that different cups are equal.
Apparently the correct way of pouring uses the Thue-Morse sequence. As explained in this guardian article, if you wanted to pour out 2 cups, A and B, you need to pour in the sequence ABBA. That's if you are happy to just use two pours per cup. If you want to make a real spectacle of yourself, and divide the coffee in 16 goes, the best sequence to use is ABBABAABBAABABBA.
I have not seen any mathematical argument that shows that the 16 step sequence produces better results than the 4 step sequence. Or that just stirring the coffee before pouring won't achieve the same results.
Cappuccino Is a Morning Drink
Did you know that no Italian would drink cappuccino after midday? It is considered strictly a morning drink.
Coffee the Italian Way, Espresso
The Italians were probably the first Europeans to come in contact with coffee, the city of Venice was a hub of trade with Arabs. The main object of the trade were spices, from India and Southeast Asia, which made Venice fabulously rich, but coffee was also exchanged.
However, the quintessential Italian way of drinking coffee, the espresso, was only invented in the 19th century. The first patent for a machine that makes coffee by passing a small amount of almost boiling water through the powder under high pressure was obtained in 1884 by Angelo Moriondo.
The pressure makes extracting oils and solids from the coffee beans very efficient. A cup of espresso has a lot more caffeine, by volume, than drip-coffee. However it is drunk in much smaller amounts.
This method produces a layer of emulsified aromatic oil foam on top of the coffee, that is known as the crema.
Espresso is the base of many different drinks served in coffee chains, these include:
- Cappuccino- Usually made with equal amounts of espresso, steamed milk and milk foam.
- Latte- espresso with a large amount of milk (usually 3-5x more than the coffee) with a little bit of foam floated on top.
- Macchiato- an espresso shot with a small amount of foamed milk. The word means "stained"
- Americano- espresso diluted with a large quantity of boiling water, giving it the same strength, but different flavour, to drip coffee. Apparently the name comes from the coffee American soldiers like having in Italy during WW2.
- Caffe Corretto- A shot of espresso "corrected" with a shot of alcohol, for example brandy or grappa.