When doing hand flushing, we usually wet the filter paper with hot water first. On the one hand, because the filter paper itself has a more or less smell, rinse with hot water to remove the smell of pulp and impurities as much as possible. The coffee made in this way tastes purer. On the other hand, we can see that there will be some keel structures on the hand-pushed filter bowl. The function of these structures is to leave some gaps between the filter paper and the filter bowl wall. When making hand-pushed coffee, the lower part of the coffee powder layer The air can be discharged from the gaps, thereby avoiding air bubbles from the powder pile, causing local temperature changes during extraction and causing uneven extraction. Therefore, before making coffee, rinse the filter paper with hot water. You can also arrange the position of the filter paper in advance so that it fits the filter bowl properly to achieve the best condition. v60 Filter bowl Cone-shaped filter paper However, as I said when I briefly answered this question in the screenshot at the beginning, if your filter paper itself has no impurities, it may not be rinsed and there will be no obvious smell. And for example, if you use pleated filter paper, its structure is strong enough and no extra finishing is needed. Well... it's not impossible not to rinse the filter paper. Without rinsing the filter paper, when brewing coffee, the original dry filter paper will absorb and lock part of the aroma of the coffee at the beginning, and it always feels like the coffee made is missing something. So I still recommend flushing the filter paper as much as possible before doing hand flushing
