How Do Filter Specifications Affect Pour-Over Coffee?

Pour-over filter paper first appeared in Dresden, where Melitta Bentz used notebook paper in a perforated copper bowl. Her company began producing drippers and filters in 1908, and its 1937 dripper became the model for today's designs. Filter specifications such as size, thickness and structure all shape flow rate and the final cup.

Bleached filters give a cleaner flavor with less papery taste, while unbleached natural filters avoid chlorine bleaching but can carry more paper note. Size and seam structure determine how evenly water passes through the bed, so matching filter specification to dripper size keeps extraction consistent and repeatable.

Before making pour-over coffee, many people first take a filter paper, fold it, and place it in the dripper before adding coffee grounds. What role does the filter paper actually play? And how should one choose between white and natural-colored filter papers available on the market? This time, Front Street Coffee starts from the origin of filter paper, sorts out the pros and cons of bleached and unbleached types, common size specifications, and further discusses how manufacturing processes and filter paper structure affect the flow rate, thereby influencing the final extraction. At the end, combined with Front Street Coffee's experience, it offers purchasing ideas that are more convenient or environmentally friendly, helping you find a balance between flavor purity, operating habits, and environmental considerations.

When brewing coffee, we usually first take a filter paper, fold it, and put it in the cup, then add coffee grounds. What role does this filter paper actually play? Also, many friends have asked Front Street Coffee: filter papers come in white and natural wood color—which is better? What are the differences between them?

Actually, these two types of filter papers each have their own advantages. Today, Front Street Coffee will chat with you in detail and give you a comprehensive understanding of filter paper.

The Origin of Filter Paper

Filter paper first appeared in a small town in Germany called Dresden. A lady named Melitta Bentz used her son's notebook paper as a filter, placed it in a perforated copper bowl as a dripper, and used it to extract coffee. Before paper filtration, people generally used rags for filtering; compared to rags, paper materials can better filter out off-flavors.

Later, Melitta Bentz founded the Melitta company in 1908 and began producing improved drippers and filter papers. The dripper style invented by the Melitta company in 1937 became the prototype of the drippers we are familiar with today.

Pros and Cons of Bleached and Unbleached Filter Paper

Since filter paper is divided into bleached and unbleached, does it actually affect health? The manufacturing of filter paper itself is also a science. Below are the differences between the two types of filter paper:

Bleached Filter Paper

Pros: 1. Less papery taste, coffee flavor is purer. Cons: 1. Many manufacturers still use "chlorine" for bleaching, which can cause environmental pollution if not handled properly. However, in recent years, many well-known manufacturers have switched to more environmentally friendly methods such as oxygen-based bleaching and no fluorescent agents. There are also bamboo fiber filter papers made from bamboo, which protect the environment and give consumers more peace of mind.

Unbleached Filter Paper

Pros: 1. Less processing, more environmentally friendly.

Cons: 1. If the filter paper is not pre-rinsed with hot water, the coffee may have a papery taste. Although it is not mandatory to rinse unbleached filter paper before brewing, if you want to make a good cup of coffee and don't care about consistency in every brew, it's hard to improve to the next level. In addition, some professional baristas use alternating hot and cold water to remove off-flavors from the filter paper to keep the coffee flavor pure.

What Sizes Do Filter Papers Come In?

Generally, filter papers are divided into the following two types:

1~2 servings

One serving of coffee grounds is about 10 grams, so this type of filter paper can hold up to 20 grams of coffee grounds.

3~5 servings

That is, you can put more coffee grounds at once, and the filter paper is also larger. Which filter paper is better to choose? If considering environmental issues, unbleached filter paper is certainly the first choice. As long as you rinse it with hot water 1~2 times, you can also remove the papery taste.

From Front Street Coffee's experience, if you want to skip the step of rinsing with hot water to remove odors, you can also buy oxidized bleached filter paper, which is more environmentally friendly. Filter paper is ultimately a case of you get what you pay for—the better the filter paper, the more expensive it is, but relatively, the papery taste will also be less than with cheaper filter paper.

The Craftsmanship of Filter Paper

‍‍

Even filter paper made of the same material can vary greatly due to different manufacturing processes. These differences are mainly reflected in the structure of the filter paper, such as the use of patterns and folds, or the thickness. The two filter papers in the picture below are both made of natural wood pulp, but the production processes are different, so the difference can be seen directly from the surface.

Differences in manufacturing processes exist not only between different manufacturers, but even the same manufacturer will use different processes to produce filter paper. The reason is simple: the structure of the filter paper affects the flow rate of the coffee, and the flow rate is an important factor affecting coffee extraction. Therefore, many manufacturers develop filter papers with different structures based on different brewing characteristics! ‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍ Take Japan's Sanyo Sangyo as an example. It has designed three versions of filter paper for different roast levels of coffee beans—T-83, T-90, T-92, corresponding to dark roast, medium roast, and light roast beans (the model number corresponds to the water temperature used). You can see the specific differences in the picture~‍

As you can see, although the filter paper material is the same, their water permeability varies due to structural changes. Not only Sanyo Sangyo, but other filter paper manufacturers also have similar practices. Front Street Coffee is just giving an example here, so I won't expand further~

The above content is compiled by CoffeeHunters, a coffee news website.