What happens if coffee is brewed for too long?

When coffee is brewed for an extended period, the extraction process continues beyond the optimal point, leading to bitterness and over-extraction. This occurs because the compounds in coffee, particularly the oils and bitter compounds, can be extracted if the brewing time is prolonged. A balanced extraction is crucial for achieving the desired flavor profile; too much extraction pulls in undesirable flavors that dominate the palate and can leave an unpleasant aftertaste.

It's essential to brew coffee within the recommended time frames to ensure that the rich, nuanced flavors are highlighted while avoiding the harshness that results from over-extraction.