Why do silver chopsticks turn yellow after three or four uses?

Silver will react with oxygen in the air to produce silver oxide, so it will turn yellow. This is a normal reaction.

Moreover, when eaten, both eggs and beef contain sulfur. Silver reacts with sulfur to produce dark brown silver sulfide, and cooked food is easier to discolor silver than raw food, because high temperature can promote chemical reaction. "Fish, meat, eggs, peanuts, beer and other foods all contain more sulfur. When the silverware touches these components under heating, it will change color and generate silver sulfide.

Extended data

1. Change chopsticks regularly for no more than three months. The discoloration of chopsticks is mainly caused by the residues on food, air, detergent and chopsticks during use. Of course, the long-term attachment and accumulation of bacteria is also a major reason for the discoloration of chopsticks. I suggest you change chopsticks once every three months.

2, refused to "wet storage", chopsticks dried before storage, to avoid mold breeding. Most household chopsticks are bamboo chopsticks or wooden chopsticks. People are used to washing chopsticks and putting them directly into the cupboard or chopsticks tube. But at this time, it is easy to breed mold in a humid environment, which leads to the surface of chopsticks being moldy or even "hairy", which will pose a threat to health in the long run.

3. Pay close attention to chopsticks (smell+look) and observe whether they are moldy. Bamboo and wood chopsticks are prone to mildew in humid environment. Generally, as long as the humidity reaches a certain level, mildew spots can be produced in a day or so. It is suggested that we should always pay attention to chopsticks in our life. If there are obvious changes (mildew spots, spots other than bamboo color) or moldy smells, please don't continue to use them and throw them away directly.