Grinding
 The fineness of the grounds has a major impact on the brewing process, and matching the consistency of the grind with the brewing method is critical to extracting the optimal amount of flavor from the roasted beans. Brewing methods which expose coffee grounds to heated water for a longer duration of time require a coarser grind than faster brewing methods. Beans which are too finely ground for the brewing method in which they are used will expose too much surface area to the heated water and produce a bitter, harsh, "over-extracted" taste. At the other extreme, an overly coarse grind will produce a weak, watery, under-flavored result.
An old-fashioned manual coffee grinder The rate of deterioration increases when the coffee is ground, as a result of the greater surface area exposed to oxygen. With the rise of coffee as a gourmet beverage, it has become much more popular to grind the beans at home before brewing, and there are many home appliances available which are dedicated to the process.
There are two methods of producing coffee grounds ready for brewing.
Grinding: burr based with two revolving elements crushing or "tearing" the bean and with less risk of burning. Burr grinders can be either wheel or conical; the latter are quieter and are less likely to clog. Burr grinders "mill" the coffee to a reasonably consistent size, which produces a more even extraction when brewed. Coffee experts consider burr grinders to be the only acceptable way to grind coffee. Chopping: Most modern "grinders" actually chop the bean into pieces (and some coffee drinkers merely use a home blender to do the job). Although enjoying a much longer life before wearing out the blades, the results are dramatically less effective in producing a homogeneously ground result and, as a result, will create inconsistent extraction and a degraded product in the cup. Blade Grinders “smash” the beans with a blade at very high speed (20,000 to 30,000 rpm). The ground coffee has larger and smaller particles and is warmer than ground coffee from burr grinders. Blade grinders create “coffee dust” which can clog up sieves in espresso machines and French presses. These type of grinders are (in theory) only suitable for drip coffee makers though even here the product is inferior as a result. They also can do a great job for grinding spices and herbs. They are not recommended for use with pump espresso machines.
Pounding: Turkish coffee is produced by infusion with grounds of almost powdery fineness. In the absence of a sufficiently high-quality burr grinder, the only reliable way to achieve this is to pound the beans in a mortar and pestle. Brewing
Coffee can be brewed in several different ways, but these methods fall into four main groups depending upon how the water is introduced to the coffee grounds. If the method allows the water to pass only once through the grounds, the resulting brew will contain mainly the more soluble components (including caffeine), whereas if the water is repeatedly cycled through the beans (as with the common percolator), the brew will contain more of the relatively less soluble compounds found in the bean; as these tend to be more bitter, that type of process is less favored by coffee aficionados.
Coffee in all these forms is made with coffee grounds (coffee beans that have been roasted and ground) and hot water, the grounds either remaining behind or being filtered out of the cup or jug after the main soluble compounds have been removed. The fineness of the grind required differs by the method of extraction.
Water temperature is crucial to the proper extraction of flavor from the ground coffee. The recommended brewing temperature of coffee is 93 °C (204 °F). Any cooler and some of the solubles that make up the flavor will not be extracted. If the water is too hot, some undesirable elements will be extracted, adversely affecting the taste, especially in bitterness.
The usual ratio of coffee to water for the style of coffee most prevalent in Europe, America, and other Westernized nations is between one and two tablespoons of ground coffee per six ounces (180 millilitres) of water; the full two tablespoons per six ounces tends to be recommended by experienced coffee lovers.
Brewed coffee continually heated will deteriorate rapidly in flavor; even at room temperature, deterioration will occur. For this reason aficionados frown upon the hotplate which is sometimes used to keep brewed coffee warm prior to serving. However, if it is kept in an oxygen-free environment it can last almost indefinitely at room temperature, and sealed containers of brewed coffee are sometimes commercially available in food stores in America or Europe.
Boiling: Despite the name, care should be taken not to actually boil the coffee (or at least not for too long) because that would make it bitter.
- The simplest method is to put the ground coffee in a cup, pour hot water over, and let it stand to cool and allow the grounds to sink to the bottom. One should not drink this to the end unless one wants to "eat" the ground coffee. The advantages of this method are that it is simple and that the water temperature is just right.
- Turkish coffee was a very early method of making coffee and is still used in the Middle East, North Africa, East Africa, Turkey, Greece, and the Balkans. Water is placed together with very finely ground coffee in a narrow-topped pot, called an ibrik (Arabic), cezve (Turkish), briki (Greek), or dzezva (Štokavian), and allowed to briefly come to the boil. It is usually drunk sweet, in which case sugar is added to the pot and boiled with the coffee; it is also often flavored with cardamom. The result is imbibed in small cups of very strong coffee with foam on the top and a thick layer of sludgy grounds at the bottom of the cup, often referred to as the "mud".
- "Cowboy coffee" is made by simply boiling coarse grounds with water in a pot, letting the grounds settle and pouring off the liquid to drink. While the name suggests that this method was derived from or used by cowboys, presumably on the trail around a campfire, it is also seen among others who do not drink coffee frequently and/or lack any specialized equipment for brewing. Some coffee aficionados actually prefer this method.
Pressure: - Espresso is made with hot water at between 91°C (195°F) and 96°C (204°F) forced, under a pressure of between eight and nine atmospheres (800–900 kPa), through a tightly packed matrix (called a puck) of finely ground coffee. It can be served alone (often after an evening meal), and is the basis for many coffee drinks. It is one of the strongest tasting forms of coffee regularly consumed, with a distinctive flavor and crema, a layer of emulsified oils in the form of a colloidal foam standing over the liquid.
- A moka pot is a three-chamber design which boils water in the lower section and forces the boiling water through the separated coffee grounds in the middle section. The resultant coffee (almost espresso strength, yet without the crema) is collected in the upper section. It usually sits directly on a heater or stove. Some models feature a glass or plastic top to view the coffee as it is forced up.
- A vacuum brewer consists of two chambers: a pot below, atop which is set a bowl or funnel with its siphon descending nearly to the bottom of the pot. The bottom of the bowl is blocked by a filter of glass, cloth or plastic, and the bowl and pot are joined by a gasket that forms a tight seal. Water is placed in the pot, the coffee grounds are placed in the bowl, and the whole affair is set over a burner. As the water heats, it is forced by the increasing vapor pressure up the siphon and into the bowl where it mixes with the grounds. When all the water possible has been forced into the bowl the brewer is removed from the heat. As the water vapor in the pot cools, it contracts, forming a partial vacuum and drawing the coffee down through the filter.
Gravity: - Drip brew (also known as filter or American coffee) is made by letting hot water drip onto coffee grounds held in a coffee filter (paper or perforated metal). Strength varies according to the ratio of water to coffee and the fineness of the grind, but is typically weaker than espresso. By convention, regular coffee brewed by this method is served in a brown or black pot, while decaffeinated coffee is served in an orange pot.
- The common electric percolator — which was in almost universal use in the United States prior to the 1970s, and is still popular in some households today — differs from the pressure percolator described above. It uses the pressure of the boiling water to force it to a chamber above the grounds, but relies on gravity to pass the water down through the grounds, where it then repeats the process until shut off by an internal timer. The coffee produced is held in low esteem by coffee aficionados because of this multiple-pass process.
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 (normally for four minutes) before the plunger, in the form of a metal foil, is depressed, leaving the coffee at the top ready to be poured. This style of "total immersion brewing" is considered by many coffee experts to be the ideal way to prepare fine coffee at home.
- Coffee bags (akin to tea bags) are much rarer than their tea equivalents, as they are much bulkier (more coffee is required in a coffee bag than tea in a tea bag).
- Malaysian coffee is often brewed using a "sock", which is really just a muslin bag shaped like a filter into which coffee is loaded then steeped into hot water. This method is especially suitable for use with local-brew coffees in Malaysia, primarily of the varieties Robusta and Liberica which are often much stronger in flavor, allowing the ground coffee in the sock to be reused.
Electronic coffee makers boil the water and brew the infusion with little human assistance and sometimes according to a timer. Some even grind the beans automatically before brewing. Connoisseurs shun such conveniences as compromising the flavor of the coffee; they prefer freshly ground beans and traditional brewing techniques. To be continued |
The fineness of the grounds has a major impact on the brewing process, and matching the consistency of the grind with the brewing method is critical to extracting the optimal amount of flavor from the roasted beans. Brewing methods which expose coffee grounds to heated water for a longer duration of time require a coarser grind than faster brewing methods. Beans which are too finely ground for the brewing method in which they are used will expose too much surface area to the heated water and produce a bitter, harsh, "over-extracted" taste. At the other extreme, an overly coarse grind will produce a weak, watery, under-flavored result.