Extraction

Extraction is the process of dissolving coffee compounds (sugars, acids, oils, caffeine) from ground coffee into water. Optimal extraction occurs when the right balance of compounds is dissolved - typically 18-22% of the coffee's soluble material. Under-extraction (too little dissolved) produces sour, acidic, weak coffee with grassy notes. Over-extraction (too much dissolved) creates bitter, astringent, hollow-tasting coffee. The extraction is controlled by grind size, water temperature, brew time, agitation, and coffee-to-water ratio. Different compounds extract at different rates: acids and caffeine extract first, followed by sugars and sweetness, and finally bitter compounds. The goal is to extract the desirable compounds (sweetness, balanced acidity) while minimizing bitter compounds.