How long can brewed coffee be safely kept warm?

Brewed coffee can be safely kept warm for up to 30 minutes. During this time, the flavor and quality of the coffee are generally well-maintained. After about half an hour, brewed coffee may start to develop undesirable flavors due to ongoing extraction and the heat from the warming source, which can cause bitterness and acidity to intensify.

Keeping brewed coffee warm beyond this timeframe risks significantly deteriorating its taste and quality. While some sources might suggest longer durations, 30 minutes is a practical guideline for preserving the optimal drinking experience. Additionally, factors like the type of coffee, the brewing method, and the temperature of the warming surface can all impact how long coffee can maintain its desirable characteristics.