How do temperature fluctuations affect espresso?

Temperature fluctuations can significantly affect the extraction process of espresso. When the brewing temperature is inconsistent, it can lead to uneven extraction of the coffee solubles. This variation can cause some compounds, which are crucial for the flavor profile, to extract too quickly or too slowly. For example, if the temperature is too low, under-extraction occurs, resulting in sour or acidic flavors, as the desirable sweet and bitter compounds haven’t been fully extracted. Conversely, if the temperature is too high, over-extraction can take place, leading to bitter flavors due to the extraction of undesirable compounds. Thus, maintaining a stable brew temperature is essential for achieving a balanced and well-flavored cup of espresso.