Extraction
Extraction in coffee refers to the process of dissolving flavors into water, influenced by three main factors: coffee, water, and temperature. This process yields four primary groups of compounds: Enzymatic/Fruity Acids (bright, fruity, and acidic notes), Maillard Compounds (nutty and roasted grain flavors), Browning Sugar/Caramels (sweet caramelized sugar notes), Dry Distillates (bitter and dry flavors).
The extraction yield directly determines the balance of coffee flavors. In espresso, the Total Dissolved Solids (TDS) typically range from 7-12%, with an optimal extraction yield of 18-22%. If the extraction is below 18%, the coffee is under-extracted, resulting in a weak, sour, and flat taste. Conversely, over-extraction occurs when the yield exceeds 22%, leading to excessive bitterness that masks desirable flavors. This principle applies to all brewing methods, requiring precise adjustments to achieve optimal flavor clarity and balance.