What is typically the outcome of under-extraction in coffee?

When coffee is under-extracted, it means that the brewing process has not allowed enough time for the water to dissolve the desirable compounds from the coffee grounds effectively. As a result, the compounds that contribute to a flat and sour taste are more prominent.

Under-extraction often occurs when the water flows too quickly through the coffee, which prevents the appropriate flavors from being extracted. This typically leads to an imbalance where the acids present in the coffee are not balanced out by the sugars and other flavor compounds that contribute to a fuller, more complex flavor profile. Instead of achieving the sweetness and richness that well-extracted coffee offers, under-extraction highlights the less desirable notes, resulting in a cup that is perceived as sour and lacking depth.

Therefore, the outcome of under-extraction is most accurately described by the resulting flat and sour taste, highlighting the importance of proper extraction time and technique to achieve a balanced cup of coffee.