Filtration. For years the coffee industry debated heavily on which brewing methods were best for making great coffee. But now, it is widely accepted that filtration brewing methods produce the healthiest and “best” tasting coffee (as opposed to immersion or percolation methods). But which filtration system is best for the popular brewing methods like pour over, Aeropress, and Chemex? Paper or metal? Bleached or unbleached?
Metal Mesh Filters vs. Paper Filters. Metal mesh filters (like these gold filters) are reusable, cheap, and more environmentally friendly than their paper counterparts. But, they are highly porous in comparison, and often leave a layer of sludge at the bottom of the cup. That sludge, while unpleasant enough to drink, is also believed to contain the harmful diterpenes cafestol and kawheol, which are known to increase bad cholesterol.
(Note. If you’re committed to metal filters you may consider upping the coarseness of your grind to eliminate some level of sludge. But tread carefully when altering grind size.)
Paper filters, on the other hand, have been found to remove most of these harmful contaminants, and during blind taste tests comparing the two, paper filters have always produced better coffee. This goes for all brewing methods that use a filter. Even Aeropress, Inc. discourages the use of mesh filters, and doesn’t produce them for the very reasons listed above.
Additionally, almost all paper filters are fully compostable, making their environmental footprint significantly smaller despite being single-use.
Rinsing Your Paper Filter. No matter what filtration brewing method you use, if you use a paper filter you need to rinse it prior to brewing. Failure to rinse your paper filters can result in a papery, woody taste being imparted in your cup. That quality edge you were supposed to gain by switching from metal mesh to paper is now lost. Rinsing with hot water right before brewing is best, but running it under the tap will also help do the job.
Bleached Filters. Bleached coffee filters are your typical white, paper filters. We use these everyday with our pour overs, but also use bleached filters when using a Chemex or Aeropress. The bleached filters are a little pricier than unbleached/natural, but have an almost undetectable impact on the final result of your brew.
Note! Bleached filters are made using a method of oxygen-bleaching which kills bacteria and whitens the filter. It is completely safe for consumption (no Clorox used here). This also makes them fully compostable.
Unbleached/Natural Filters. Don’t be fooled by the holistic sounding nature of unbleached coffee filters. These are your typical brown coffee filters. They are more natural and often cheaper, but leave way more of that papery, woody flavor in your brew. We suggest ponying up the few extra cents/dollars for bleached filters.