Blog
Who Invented the Paper Coffee Filter? Melitta Bentz’s Idea
How Melitta Bentz combined paper with a supporting cup, what her 1908 utility model was, and how later filter bags changed the design.
Quick Answer
Melitta Bentz developed a paper coffee filter in 1908, using paper supported by a perforated cup to keep grounds out of the drink. Her documented German protection was a utility model. The filter-bag patent filed in 1935 and published in 1937 describes a later design, not that original registration.
On This Page8 Sections
Paper and its holder do different jobs. The holder supports the wet paper and coffee bed; the paper retains grounds while brewed coffee passes through. That pairing makes Bentz's idea easy to recognize even though today's filter shapes came later.
The Grounds Problem Behind Bentz's Filter
In Melitta's account of the invention, Bentz used a perforated brass cup and her son's blotting paper. The paper provided the filtering layer, while the cup held it in place and allowed liquid to drain.
The used paper could then be lifted out with the grounds. A durable support and a replaceable liner shared the work, rather than requiring the support itself to act as a fine filter.
What Was Registered in 1908?
The German Patent and Trade Mark Office (DPMA) identifies Bentz's right as a Gebrauchsmuster, or utility model. It gives June 20, 1908 as the application date and July 8 as the registration date. The business entered the commercial register on December 15.
DPMA says the early utility-model papers were lost during the Second World War. Its 2023 annual report includes later patent illustrations; those drawings belong with their own dates, not a caption identifying them as the original 1908 filing.
Paper Coffee Filter Milestones
| Date | Milestone |
|---|---|
| June 20, 1908 | Bentz's utility-model application. |
| July 8, 1908 | Utility model registered. |
| December 15, 1908 | Business entered in the commercial register. |
| July 25, 1935 | Application filed for the later filter-bag patent DE640946C. |
| January 15, 1937 | DE640946C published. |
How Later Paper Bags Changed the Design
DE640946C concerns a cup-shaped filter bag and how to make it. It discusses a construction with a separate base and side wall, then a bag formed from one cut piece of paper with joined edges. Reinforced-bottom alternatives and the supporting holder are also part of the discussion.
This is a practical manufacturing problem: a sheet must become a bag that holds its shape in the brewer. The paper's outline, folds and joins affect how it can be made and supported. The later patent makes that development visible, decades after Bentz's first arrangement.
Match the Paper to the Holder
The enduring idea is a paper layer with suitable support. Modern papers and holders come in different shapes and sizes, so the useful question for your own coffee is which paper fits the brewer you have.
Our coffee filters guide covers present-day materials, fit, flow and cleanup. For a modern Melitta setup, use the Melitta cone guide; the pour-over guide covers the wider brewing family.
A Personal Note on Filter Design
A personal note: I find the paper filter interesting because its usefulness depends on several small design choices working together. The paper needs a shape, the shape needs support, and the finished arrangement needs to be practical to make and use. That is the kind of detail I want an invention story to explain. I pay particular attention to captions because a later drawing can easily become the image I associate with an earlier date. Keeping the document and its date together helps me appreciate the design more clearly. It also leaves room for the improvements that followed the familiar origin story.
Sources
- DPMA: Melitta Bentz
- Melitta: The Melitta Story
- DE640946C: Filter bag in cup shape
- DPMA Annual Report 2023: Utility models, historical Melitta Bentz section