Limescale or coffee residues (black stains) could build up inside your coffee jug during use. To clean your coffee jug, you can use a soft sponge with washing liquid. Please ensure you do not immerse the jug in water or place it in the dishwasher. 

To remove limescale and black stains, pour one cup of heated water into the coffee jug and half a cup of vinegar or lemon juice. Let it sit for 30 to 60 minutes, then rinse the jug with fresh water. If some stains are still there, please repeat the cleaning process for a second time. 

For more information, please refer to the User Manual or contact us for further assistance.