Extraction in the context of coffee brewing, is the process of dissolving soluble solids and emulsifying aromatic oils in water. Coffee extraction is a precise process, and there are a few parameters that will determine the taste, aroma, and strength of the brewed coffee. Correctly brewing coffee requires using the correct amount of coffee grounds, extracted to the correct degree, (largely determined by the correct time), at the correct temperature.
Different coffee brewing methods use different brewing parameters, and have distinctive flavor and taste profiles.
Coffee is a liquid solution of various substances found in the coffee bean dissolved in water. The extraction of these substances can be improved by increasing the solubility. Solubility can be increased by temperature, pressure, and agitation. Extraction can be tweaked by changing the grind size, and the extraction time.