In fact, this is a widespread misconception. "Washing tea" is a presumptive interpretation of the brewing process for certain teas. In professional tea culture, this step is standardly referred to as the "warming and moistening brew." It is a technical method to make tea taste better, not to "wash away dirt from the tea leaves."

Many teas undergo "rolling" during processing, which not only adjusts the shape of the tea leaves but, more importantly, squeezes out some tea juice from the leaves. After drying, the solid components of this tea juice adhere to the leaves and quickly dissolve into the tea soup during brewing.

Of course, the unexpressed portion slowly dissolves into the water as the dried tea absorbs water and expands, maintaining a certain concentration in the tea soup. Controlling the rolling process helps regulate the content of different components in the tea soup during brewing—varying relative proportions of these components can result in different taste experiences. If the tea leaves are rolled very tightly, making it difficult for the tea juice inside and outside the leaves to enter the water in an orderly manner, the taste of the tea soup becomes less pleasant.

For such teas, moistening the leaves with water at a certain temperature before formal brewing allows the leaves to slightly unfurl, making it easier to control the consistency of strength in each subsequent brew. This step is therefore called the "warming and moistening brew." For most oolong teas and tightly compressed pu-erh teas, professional tea artists often perform this step. Of course, even for oolong and pu-erh teas, if the leaves are already very fragmented and have a high extraction rate, the warming and moistening brew may be unnecessary.

So, are tea leaves dirty, and do they need washing? The so-called dirt primarily refers to dust, microbes, and pesticide residues. There is a certain concentration of dust particles in the air; eating, talking, and even breathing introduce a certain amount of dust into our bodies. The dust on tea leaves is negligible in comparison. Most microorganisms require moisture to survive; the long shelf life of tea is due to its minimal moisture content, which is highly unfavorable for microbial growth.

As for pesticide residues, not only are teas from正规厂家的茶叶农残会被控制到国家标准之内正规厂家生产的茶叶农药残留控制在国家标准以内正规 manufacturers controlled to within national standards, making them safe to consume, but even if they were "超标"超标exceed limits, the fear is often exaggerated—tea consumption amounts to only a few grams per day, and unlike vegetables and fruits, tea is not eaten directly. The amount of pesticide residue that could be ingested from tea is very limited. Conversely, if there were significant pesticide residues in tea, "washing" would remove very little—pesticides need to adhere well to the tea leaves to be effective, and hoping to effectively remove them through a single brew while retaining the tea's components is largely wishful thinking.

In short, qualified tea doesn't need "washing," and unqualified tea won't be helped by "washing." For teas that infuse easily, such as conventional green tea and black tea, the first brew is often the most delicious.