The Coffee Wiki
Advertisement

Brewing is the typical method of preparing roasted coffee beans for drinking. While there are several methods for brewing coffee, nearly all involve infusing ground coffee beans with water over a period of time. Coffee brewers can range in complexity from a vessel in which coffee grounds and hot water are combined for several minutes to an espresso machine which "presses" hot water through a puck of coffee at a high pressure to produce a highly concentrated coffee.

History[]

The history of coffee consumption is a bit contested. The earliest confirmed method of coffee consumption was similar to today's drip brew infusion methods. As recorded in the 16th century, beans were dried, roasted, then ground and boiled to create a black coffee drink. There are also earlier, unconfirmed reports from several different accounts of beans that were originally dried and then simply eaten. These reports are less reliable.

Whatever the original origin, the modern coffee and coffee trade we're all most familiar with began with invention of the Ibrik; this allowed for a more skillful technique of brewing and a widespread adoption of coffee in Islamic religious practice[1].

Coffee trade began to grow quickly, and saw a huge boom of popularity in Western cultures. By the 18th century, the French had developed a drip brewing technique, using a cloth bag as a filter, which allowed the coffee grounds to be kept separate from the resulting liquid coffee. This technique allowed for steeping the coffee at a lower temperature, as it was not brewed while constantly adding heat. Additionally, by not leaving the grounds in the coffee until consumption, it reduced the period of extraction and the resulting bitterness[2]. The technique of steeping coffee at a temperature below boiling did not see widespread adoption until the 19th and into the 20th centuries. Today, most Western brewing methods use water below boiling point[3].

Common Factors[]

There are several different ways to brew coffee, and each with a different best method. However, four factors are consistent across all brewing methods:

  • Amount of coffee
  • Type of grind
  • Water (type and temperature)
  • Extraction time

Amount of Coffee[]

The ratio of coffee to water determines the strength and flavor of the coffee (and the caffeine content). When preparing good coffee, the proper water-to-coffee ratio is vital for achieving the proper extraction - this will make more subtle flavors apparent. The generally recommended measure is two tablespoons for every five to six ounces of water[4]. A greater ratio results in a strong, bolder coffee, but it's important to note that without adjusting other variables like time and temperature of the water, changing ratio of coffee alone can result in under-extracted or over-extracted brews.

Type of Grind[]

The "ideal" coffee grind varies greatly depending upon the brewing technique that is used. By having a finer grind, more surface area of the coffee is exposed, thereby allowing more flavor compounds and coffee solids to be extracted into the coffee. The fineness of the grind will significantly influence the ideal temperature of water and exposure time variables. For example, if the coffee is ground too fine, filters on drip or pour-over brews will increase the exposure of the grounds to water, and result in an over-extracted brew. Additionally, grinding coffee too fine can result in heating up the coffee to a point at which the more subtle flavors are lost. The exception to this is when grounds are intended to be unfiltered, such as in Turkish coffee, for which the coffee is ground into a fine powder before brewing and the bitter flavor of the boil is intentional[5].

Water[]

While it is often overlooked as a factor in brewing coffee, it's vital for the outcome. Ninety-nine percent of coffee is water. Both the type of water and the temperature of the water at time of brewing are essential factors in brewing coffee. If the water used to brew coffee has a particular taste, it will likely be passed on to the coffee itself. Hard water will tend to mute the more subtle flavors in most coffees, with water softeners making the situation worse[6].

Spring water or filtered water generally add no flavors to coffee, and are often recommended for brewing coffee. However, distilled water is not typically recommended, as the lack of minerals and ionic compounds in the water will limit the full infusion of the coffee. The Specialty Coffee Association of America recommends between 50 to 100 parts per million of minerals disolved in water used to brew coffee[7].

The temperature of the water used to brew coffee determines the extraction of the flavor compounds, coffee solids, and coffee oils - each contributing to the final flavors in the cup. The rate at which coffee is extracted into the water is directly related to the temperature of the water. The hotter the water, the quicker the extraction. At a higher temperature, desirable flavors are typically more fully extracted to the cup. This can also result in greater acidity, which is sometimes undesirable. At a lower temperature, a longer extraction time is required, and some compounds and flavors are fully extracted while others are not at all in the resulting coffee. In cold brews, for example, the longer exposure and very low temperature results in a less acidic, "brighter" tasking coffee that is preferred by some. Similarly, too high of a temperature exposed for too long a time will result in a bitter cup of coffee, as desirable compounds are broken down[8]. A water temperature of between 195 and 205 degrees (just below boiling) is considered to be ideal for brewing coffee[9].

See also[]

References[]

  1. Joel Schapira (1996). Book of Coffee and Tea: A Guide to the Appreciation of Fine Coffees, Teas and Herbal Beverages, 6-7. ISBN 0312140991.
  2. Harold J. McGee (2004). Book On Food and Cooking: the science and lore of the kitchen, 441. ISBN 0684800012.
  3. Kenneth Davids (2001). Coffee: A Guide to Buying, Brewing & Enjoying, Fifth Edition, 123. ISBN 031224665X.
  4. Kenneth Davids (2001). Coffee: A Guide to Buying, Brewing & Enjoying, Fifth Edition, 136. ISBN 031224665X.
  5. Kenneth Davids (2001). Coffee: A Guide to Buying, Brewing & Enjoying, Fifth Edition, 119-120. ISBN 031224665X.
  6. Kenneth Davids (2001). Coffee: A Guide to Buying, Brewing & Enjoying, Fifth Edition, 126. ISBN 031224665X.
  7. Specialty Coffee Association of America - Brewing
  8. William H. Ukers (1922). “Preparing the Beverage”, All about Coffee, 719. ISBN 0810340925.
  9. | Equal Exchange - Brewing Tips
Advertisement