Brewed coffee has a burnt or bitter taste.

Usage adjustments:

• Do not leave coffee on the warming plate for more than 1–2 hours; use a thermal carafe if you need longer holding time.
• Use a medium grind and follow Oster's recommended coffee-to-water ratio.

Clean thoroughly:

• Run a descaling cycle with vinegar and water.
• Wash the carafe, brew basket, and showerhead area with warm soapy water to remove coffee oils.

Check warming plate behavior:

• After brewing, feel (carefully) how hot the warming plate gets. It should keep coffee hot but not boiling.
• If coffee boils or scalds quickly, the warming plate thermostat may be faulty and require replacement.