We recommend using citric acid or sodium bicarbonate (baking soda) to keep your TC products clean. Baking soda has an antibacterial effect and dissolves calcified residues easily. For cleaning, put a table spoon of citric acid or baking soda into hot water, then add cold water, put it into the TC carafe or tumbler and leave it there for 12 hours. Make sure you wash it out completely before using it again. You can also use mild dish detergents, as with other household glass products. We do not recommend placing them in the automatic dishwasher.