Klarstein coffee maker emits a sour or rancid smell from brewed coffee.

Safety first: Unplug before deep cleaning.

Thorough cleaning:

• Wash the filter basket, permanent filter (if fitted), and carafe with hot soapy water and rinse well.
• Clean the shower head and brew chamber with a soft brush.
• Empty and wash the water tank regularly.
• Run a brew cycle with just water and a small amount of white vinegar, then several cycles with clean water.

For grinder models, run grinder cleaning pellets or grind a small amount of rice (if allowed by Klarstein) to absorb oils, then discard.