Over time, a persistent brown coating appears on the walls of cups. It cannot be washed off with a regular sponge and raises the question — is it harmful to drink from such dishes?
Nutritionist Daria Yarygina answered this question, explaining where the coating comes from and how to get rid of it.
What tea and coffee coatings are
The coating on the walls of cups forms due to tannins and caffeine — natural phenolic compounds that interact with minerals in water, the expert explained. These substances give beverages astringent taste and aroma, but when they settle on the walls of the cup, they form a characteristic dark film.
Is the coating on cups dangerous
The coating looks unattractive, but in reality, it does not affect the beverages themselves.
"The coating itself is not toxic and is not harmful to health if the dishes are washed regularly," the nutritionist clarified.
However, over time, dust, grease, and microorganisms settle on the inner part of the dishes. All of them are "trapped" on the contaminated walls, and the drinks acquire an unpleasant aftertaste and smell.
How to safely remove the coating
According to the nutritionist, powerful household chemicals for washing cups are not necessary.
"The coating from tea and coffee can be easily removed with baking soda, citric acid, or damp salt," Daria Yarygina specified.
