There is a kind of tea ball wrapped in thread. What kind of tea is this?

It should be partridge tea.

Partridge tea is one of the "three treasures" in Dongshan, with round leaves and sweet taste. It is a peculiar wild tea. The tea it makes is golden in color, special in taste and rich in aroma, and the first person who drinks it will taste the faint medicinal taste. So some people say that partridge tea is not tea but medicine. In fact, there is some truth in saying this. Old people in Dongshanling often say: "Partridge tea is not ordinary tea. It can relieve greasy and cure colds. Every time you catch a cold, you can get the general effect of Chinese herbal medicine by cooking a bowl of thick partridge tea. " The dual-purpose of tea and medicine is the characteristic of partridge tea. It is not only sweet and refreshing, but also has the effects of clearing away heat and toxic materials, quenching thirst, promoting digestion, lowering blood pressure, reducing weight, strengthening the spleen and nourishing the stomach, and can also prevent and treat colds, so it has been praised as "Ganoderma lucidum" by scholars of all ages.