is as much of an art as it is a science. The history of brewing devices
is rich, and methods of brewing are culturally dependent. Of the thousands
of machines and brewing devices invented since the advent of coffee consumption
only a few have gained worldwide popularity. The methods discussed below
are recommended since they have been found to maximize the extraction of
the beneficial flavors of coffee, while minimizing the extraction of bitter
and undesirable components.
General rules: The following general rules apply to each brewing method discussed. Coffee should be brewed for 4.5-5 minutes using a ratio of 55 grams of ground coffee per liter of filtered water (195-205°F). It is convenient to use 2 tablespoons of coffee per 6 ounces of filtered water. Filtered water and spring water are recommended. Tap water imparts off flavors to the coffee and since some minerals are essential to coffee flavor, distilled water is not recommended.
French Press: The best way to control the time and temperature is to use a French press. French press is essentially open-pot coffee with a sophisticated method for separating the grounds from the brew. The pot is a narrow glass cylinder. A fine-mesh screen plunger fits tightly inside the cylinder. You put coarse-to-medium ground coffee in the cylinder, pour water just short of boiling over it, and insert the plunger in the top of the cylinder without pushing it down. After about 4 minutes, when the coffee is thoroughly steeped, you push the plunger through the coffee, clarifying it and forcing the grounds to the bottom of the pot. The French press offers unparalleled flavor due to perfect extraction time and delivery of the volatile oils that are often trapped in filters. A French press is also the least expensive brewer available.
Pot: The vacuum pot is a clever device invented by Robert Napier
in 1840 that prepares an exceptional cup of coffee with a potent aroma. This
is an appropriate alternative for those who have an aversion to the taste
of the paper filters from the drip brewers or who do not like the sediment
in the bottom of the cup from the French press method.
Filter Drip Brewing: About 70% of
the coffee consumed in the United States is brewed with paper filters, a method
that produces coffee in the classic American style: clear, light-bodied, with
little sediment or oil. Any other brewing method (except cold water concentrate)
produces a coffee richer in oils and sediments and heavier in flavor than
the typical American cup of filter coffee.
Pour-Over Filter Brewing: Fewer
and fewer people choose to pour the water over the coffee themselves when
automatic filter drip brewers sell for as little as $15 or $20. Reasons to
pour-over yourself: The basic plastic cone and glass decanter set is still
the cheapest brewing device on the market, short of a tin-can and coat hanger;
pour-over units do not require counter space; you can be absolutely sure all
the ground coffee is saturated because you are doing the pouring yourself;
and you can congratulate yourself on being a coffee purist.
or Instant Coffee: Making instant
coffee is not really brewing, rather mixing and stirring. However, at first
glance (not taste), instant coffee does seem to offer many advantages: It
stays fresh longer than ordinary roasted coffee; it eliminates the mistakes
that can occur when brewing ordinary roasted coffee; it can be made quickly;
it can be mixed by the cup to individual taste; and it contains somewhat less
caffeine than regularly brewed coffee. Furthermore, because the process of
producing instant coffee neutralizes strong or unusual flavors, the manufacturer
can use cheaper beans and pass the savings on to the consumer.
Espresso: The word espresso is derived from the Italian word for express since espresso is made for and served immediately to the customer. A double espresso is a 47-62.5 mL (1.5-2 ounce) extract that is prepared from 14-17 grams of coffee through which purified water of 88-95°C has been forced at 9-10 atmospheres of pressure for a brew time of 22-28 seconds. The espresso should drip out of the porta-filter like warm honey; have a deep reddish-brown color, and a crema that makes up 10-30% of the beverage. The espresso is ready to be brewed after correctly roasting, blending, grinding, dosing, and tamping the coffee. Before placing the porta-filter in the group head, allow 2 ounces of water to flow through the head. Tightly place the porta-filter in place and place a pre-warmed glass below the spouts of the porta-filter. Use the manual switch to begin the pre-infusion cycle. This distributes water over the top of the espresso pellet to allow it to expand and seal properly before blasting it with pressurized water.
For 1.5 ounces of espresso, the extraction should take between 23-30 seconds where the time starts when the espresso begins to flow from the spouts. The pour should look like warm honey dripping from the spouts. Manually stop the extraction if the espresso turns a slight shade lighter in color. If it took longer than 30 seconds, adjust the grind to be larger in size. If it took less than 25 seconds, adjust the grind to be smaller. Do not vary the pressure you apply in tamping since you only want to adjust one variable at a time. By adjusting the tamping pressure you are simultaneously adjusting several parameters that will often result in an undesirable product even if you do attain the right timing.