Filter paper is an essential filtering tool for making hand brewed coffee. Although it may not look very eye-catching, its impact on coffee cannot be underestimated. If you communicate with coffee players, you should have heard many questions related to filter paper, such as whether filter paper needs to be wetted, whether filter paper has a paper smell, how much hot water should be used for wet filter paper, and so on.
Should the filter paper be wetted?
Many friends often struggle with the question of whether to wet the filter paper before brewing coffee when they first get started. The reason for the dilemma is often due to being warned that it is necessary to wet the filter paper before making coffee. But in daily life, it is often seen that the filter paper is not wet. So this has made many friends wonder, is it necessary to wet this filter paper before making coffee?
In addition to personal preferences, whether the filter paper gets wet or not also needs to be determined based on specific circumstances. We can measure it from the following three perspectives: the adhesion between the filter paper and the filter cup, the taste of the filter paper, and the storage environment of the filter paper.
Fit filter cup: Many filter cups, like V60, have a considerable number of guide ribs, which not only support the filter paper to create exhaust space for coffee powder, but also guide the water flow. And if we want these ribs to play their role, we need to make the filter paper fit tightly with the filter cup.
There are many ways to make the filter paper adhere to the filter cup, such as pre wetting the filter paper with water or filling it with coffee powder. For beginners who are not familiar with the specific operation of the latter, it is still recommended to wet the filter paper with water to make it adhere to the filter cup.
Storage environment of filter paper: Secondly, the storage environment of filter paper is also one of the factors for us to measure whether it needs to be pre wetted. If the filter paper is stored in an open environment, it is easy to accumulate a lot of dust in daily life. In this case, we need to pre wet it to wash away the “stains” attached to the filter paper; If the storage environment of filter paper is relatively sealed and not easily adhered by dust, then we can decide whether to keep it moist according to our own preferences or other factors.
The smell of filter paper: Finally, the smell of filter paper! Earlier, the main purpose of wet filter paper was not only to adhere to the filter cup, but also to wash away the paper odor on the filter paper. Due to the manufacturing process, many filter papers retain a significant amount of pulp flavor. If this flavor is not removed, it will mix with the coffee solution during the brewing process, resulting in a subtle paper like taste in the final coffee.
With the improvement of technology, many filter papers no longer have a distinct pulp smell, so some filter papers do not need to undergo deodorization operations. Therefore, whether to wet the filter paper in advance depends on whether the filter paper itself has a noticeable odor. How can we determine if the filter paper has a noticeable paper odor? It’s very simple and abstract! We only need to use a small amount of hot water to rinse the filter paper, and then taste the water separately to see if there is a noticeable paper smell ….
Should I use cold water or hot water to wet the filter paper?
The next issue is the water temperature when using wet filter paper! When we decide to wet the filter paper, the next thing we need to consider is the water temperature when wetting the filter paper, which is also very particular!
When the purpose of using wet filter paper is to remove paper odor, it is best to use a slightly warmer water temperature for the wet filter paper. Just as hot water can accelerate the dissolution of coffee flavor compounds, it can also better dissolve paper flavors. In addition, the water temperature of wet filter paper also depends on whether preheating tools such as filter cups and sharing pots are needed. If the material of the filter cup is a ceramic with high specific heat capacity, it is best to use hot water to wet the filter paper. Because filter cups made of this type of material will first absorb the hot water temperature during boiling to replenish themselves without preheating, thereby affecting the extraction process. The same principle applies to whether the sharing pot needs to be preheated, but it affects the coffee liquid rather than the hot water.
Post time: Sep-12-2025