Generally, a tea bag can be steeped twice, but it's not very durable and should not be steeped more than three times. In terms of steeping time, from the first infusion to the last, the time should ideally not exceed 12 hours.
Some brands of multi-tiered tea bags, such as Tiffany's, are very durable and can be steeped multiple times without losing flavor. These tea bags come with a saucer to control the concentration. They used to be available at Tiffany's tea shops, but now they are sometimes found on platforms like JD.com and Taobao.
However, a tea bag should not be steeped for two days. Tea leaves are prone to spoilage overnight, and contact with enzymes in the air can produce substances harmful to the body. It's best not to steep tea for too long, only 1 to 2 times.
If a tea bag has been left overnight, it can be used as a mouthwash, but it should not be consumed. Generally, a tea bag can be steeped about three times, not for a whole day. It's best to drink it immediately after steeping to avoid affecting the taste or causing bacterial growth.
When considering whether a tea bag can be steeped overnight, it also depends on the type of tea. Green tea typically needs 3 to 5 infusions, while Pu-erh tea and similar varieties are more resistant and can be infused more than ten times.
Although theoretically overnight tea bags are still drinkable, the taste may be unpleasant, especially for green and flower teas. Therefore, it's better to brew a fresh bag.
In general, tea bags should not be brewed again after being left overnight. The proteins and sugars in tea bags are prone to bacterial growth and nutrient loss if left for too long, which is detrimental to health.
