When choosing between metal or paper, the answer depends on the body of your brew.
When it comes to which filter is better for manual and automatic drip coffee makers—paper or metal—the experts are divided. Some say brewing through paper filters can impart papery off-flavors and trap some of the delicate aromatic oils that enrich coffee flavor. Others insist that metal filters produce a weaker brew and that their larger openings allow too many grounds to pass through. To see for ourselves, we ground enough beans for two batches of coffee, brewing one batch in a manual-drip coffee maker using a paper filter and the other in a second manual-drip using a metal filter. Our in-house panel of experts found the two brews virtually identical in flavor, with no unwanted tastes or lack of complexity in the paper-filtered coffee. The coffee made with a metal filter clearly had more body from the presence of fine particles and tasted ever so slightly weaker than the paper brew. Our recommendation? Use paper if you like your coffee without any particles in the mix. Metal is fine if you prefer coffee with body, but since water passes through this kind of filter faster than paper, grind the coffee a little finer to achieve the proper extraction.