For thousands of years, countless scholars and literati have had a special fondness for tea, and tea tasting has become an elegant activity. Tea culture has a long history, dating back thousands of years. The nutrients in tea, such as tea polyphenols and tea polysaccharides, have exceptional health benefits. Especially tea polyphenols, which have excellent anti-cancer and cancer-suppressing effects. However, not all teas contain these beneficial nutrients, and not all teas are safe to drink. Some teas should never be consumed, no matter how good they may seem.

First brew tea:

Many people enjoy drinking the first brew of tea, believing it to be the most nutritious. In reality, the first brew contains the highest amount of pesticide residues. After tea farmers pick and process the leaves, pesticide residues remain on them. Many pesticides are water-soluble, meaning the first brew has the highest concentration. Rinsing tea is a good practice. To avoid losing too many nutrients, use cooled boiled water to rinse the leaves before brewing with hot water. This reduces pesticide residues and safeguards your health.

Over-steeped tea:

Many people drink the same cup of tea all day. There’s an old saying describing office workers: "A newspaper, a cup of tea, and that’s the day." After rinsing, 85% of tea polyphenols are already dissolved in the first brew, with the remaining 15% in the second. By the third brew, very few nutrients remain. Over-steeping depletes the tea’s nutritional value, making it essentially devoid of benefits.

Spoiled or contaminated tea:

If stored improperly, tea can spoil. The nutrients may deteriorate, and microorganisms can multiply. At this point, the tea has little nutritional value and may even harm your health. Tea should be stored in a sealed container away from strong-smelling items like cosmetics, which can cause it to absorb odors and lose its original flavor.

Overnight tea:

Some people don’t mind overnight tea, while others avoid it at all costs. Tea left standing for too long can breed bacteria, and the nutrients in the tea provide a breeding ground for them. Drinking such tea may not directly cause cancer, but it is harmful to health and should be avoided.