With brewing coffee, as with cooking food, each ingredient and step along the way shapes the end result. The technique, roast, coarseness of grounds, temperature and quality of water are all known to influence the flavor of a cup of coffee. But often overlooked is the filter — the element through which everything passes.
Paper filters are the norm, preferred for their low cost and easy disposal. But steel and cloth filters carry their own respective advantages, enriching the flavor and texture of a pour-over in different ways. “The most important factor in filter selection is to ensure that [the medium] does not create any negative distractions,” explains Blue Bottle Coffee Director of Quality Control Benjamin Brewer, noting that filter material is ultimately a matter of personal preference. Here’s what you need to know about each type.
For a cleaner mouthfeel. “Paper filters tend to filter out more solids and absorb more oil,” Brewer explains; this makes them well suited to a broad range of roast styles. The caveat is that the filter’s pulp and composition can influence the overall flavor of a coffee extraction — recycled paper filters will yield a “papery” taste, while bleached filters can leave dry, astringent notes.
The solution lies in simply rinsing the filter with hot water to remove what Brewer calls “non-coffee attributes.” The result is a more clarified extraction and a coffee with a cleaner mouthfeel.
Flannel Cotton Nel Filter by Hario $15
For luxurious, silky texture. Cloth filters, commonly used with the Hario Nel brewer, absorb oils in much the same way that paper filters do, but their woven texture results in what Brewer calls “luxurious, silky, layered cups.” While cloth filters are reusable, they do need to be replaced after a few months of use. “Oils get absorbed [into the fabric] and don’t get fully removed, even with cleaning regimens,” Brewer says. “This is a scenario where, over time, there is a possibility that the filter will produce negative, distracting qualities.”
Stainless Steel Filters
KONE Coffee Filter for Chemex by Able Brewing $60
For bold flavor. Whereas paper and cloth filters absorb oils during the brewing process, stainless steel, being non-porous, does not. “Methods used to allow for more solids [ultra-fine grounds] or oils in the cup, like stainless steel filters, can produce wondrous coffee,” Brewer says.
“Higher thresholds of oil and solids in coffee can transmit more volatile nuances, which means, in some instances, more complexity.” The result, according to Brewer, is a “perception of increased fullness of body and mouthfeel.” While desirable in most instances, increased oils can lead coffees with “excessive roast influence” to grow bitter.