At the beginning of the 20th century, Bentz realized that the process for brewing coffee was difficult and frustrating. From her experience as a housewife, she converged upon three major pain points with coffee makers. First, at this time, coffee was usually prepared with percolators. This led to a phenomenon known as overextraction, where too many compounds are extracted from the coffee grounds [1]. Percolators work by cycling boiling water through coffee grounds. However, this constant overexposure to high temperatures, combined with already brewed coffee cycling through due to poor filtration, led the percolator to be particularly susceptible to overextraction [2]. Secondly, already existing espresso filters left grounds in the drink. Not to mention it took up to five minutes to produce a cup of espresso [3]. Bentz then turned to linen bags or cloth filters, but they were difficult to use and impossible to clean. Therefore, Bentz’s solution aimed at creating better-tasting coffee while making the process easier. After some trial and error, she stumbled upon a new solution. She ripped a piece of blotting paper from her son’s notebook and placed it in a perforated brass pot. Next, she added ground coffee and poured water over it, dripping through the holes in the pot into a cup [4]. Bentz had just created the coffee filter. This solution addressed the pain points in a number of ways. The clean-up process was easier and more hygienic as the paper filter went straight into the trash, reducing the presence of messy coffee grounds. In Jun 1908, Bentz was granted a patent for her paper filter by The Imperial Patent Office in Berlin.

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