What Happens When Brewing Coffee

What happens when coffee is brewed

What Happens When You Brew Coffee
In making coffee, your aim is to extract flavorful solids (including coffee oils and sucrose and other sugars) from the ground beans without pulling bitter, astringent tannins along with them. How long you brew the coffee determines how much solid material you extract and how the coffee tastes. The longer the brewing time, the greater the amount of solids extracted. If you brew the coffee long enough to extract more than 30 percent of its solids, you will get bitter compounds along with the flavorful ones. (These will also develop by letting coffee sit for a long time after brewing it.)


Ordinarily, drip coffee tastes less bitter than percolator coffee because the water in a drip coffeemaker goes through the coffee only once, while the water in the percolator pot is circulated through the coffee several times. To make strong but not bitter coffee, increase the amount of coffeeŚnot the brewing time.
 

How Other Kinds of Processing Affect Coffee
Drying. Soluble coffees (freeze-dried, instant) are made by dehydrating concentrated brewed coffee. These coffees are often lower in caffeine than regular ground coffees because caffeine, which dissolves in water, is lost when the coffee is dehydrated.


Decaffeinating. Decaffeinated coffee is made with beans from which the caffeine has been extracted, either with an organic solvent (methylene chloride) or with water. How the coffee is decaffeinated has no effect on its taste, but many people prefer water-processed decaffeinated coffee because it is not a chemically treated food. (Methylene chloride is an animal carcinogen, but the amounts that remain in coffees decaffeinated with methylene chloride are so small that the FDA does not consider them hazardous. The carcinogenic organic solvent trichloroethylene [TCE], a chemical that causes liver cancer in laboratory animals, is no longer used to decaffeinate coffee.)

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