Coffee filters are a daily feature in many of our lives and choosing the right filter can be, well, tricky. Aside from numerous brands to select between, there are also a host of different types of coffee filters to choose from, each with its own pros and cons. Today, we are breaking down coffee filter options but before jumping in, it is important to talk about coffee and cholesterol. While different coffee filters highlight different elements of a coffee’s character, the most important relationship between brewed coffee and coffee filters is measured in diterpenes.
Unfiltered brewed coffee contains diterpenes cafestol and kahweol, more commonly referred to as lipids or oils, that can elevate LDL cholesterol. According to a 2020 study published by the European Journal of Preventive Cardiology, “unfiltered coffee contains 30 times more diterpenes than a cup of filtered coffee1“. Diterpenes release during brewing and are easily and effectively removed from brewed coffee with a filter — the finer the pores / holes in the filter, the more effective the filtration. The more effective the filtration, the lighter, cleaner, and brighter your cup. Now let’s explore the options!
Metal filters
Metal filters are made from either stainless steel or aluminum, create a wonderfully rich, creamy, flavorful cup, and are the next best thing to an unfiltered coffee. Metal filters, including the famed gold filter, are pricer than paper filters at the onset but can last for years if properly cared for. While metal filters are a great option for someone seeking a sweet, creamy, filtered up with a hint of brightness, their fine mesh makes them the least effective filter option for removing diterpenes and micro-fines (small coffee granules) during brewing.
Pros: Removes some diterpenes during brewing, durable, reusable, best option from a long-term cost perspective, environmentally-friendly.
Cons: Does not remove diterpenes and micro-fines as effectively as a paper filter.
Paper filters
Paper filters are by far the best option for producing a clean, bright, nuanced, diterpene / oil-free cup of coffee. Paper filters are made of either natural brown paper or bleached white paper. Both natural and bleached filters are highly and equally effective at removing oils and micro-fines during brewing. While one is not necessarily better than the other, there are a few differences. Natural paper filters may release woody paper fibers into your coffee while brewing. While these fibers are not harmful they can impact the flavor of your coffee — they are also easily removed by pre-wetting your filter (quickly running a small amount of water through the filter before brewing). Generally, high-quality natural filters will not release any discernible fibers into your cup. White paper filters are bleached filters that have been whitened through either a chlorine or oxygen process — both processes are perfectly safe and both produce clean, clear cups of coffee. From an environmental standpoint, natural filters are better for the environment than white filters and oxygen-processed filters are better for the environment than chlorine-processed filters. All paper filters are biodegradable and natural paper filters can be added to compost piles.
Pros: Effectively removes diterpenes and micro-fines during brewing, easy cleanup.
Cons: Greater long-term cost, least environmentally-friendly option.
Cloth filters
Cloth filters, relatively new to the American market, are made of either cotton or linen. Tightly woven, cloth filters have shown to effectively remove micro-fines and some diterpenes, mainly cafestol, during brewing. For comparative purposes, cloth filters generally fall between metal and paper filters. Cloth filters are more effective than metal filters and less effective than paper filters at removing diterpenes, and cloth filters produce a cup that is lighter and brighter than one brewed through a metal filter but richer and sweeter than one brewed through a paper filter. Cloth filters are washable, reusable, and environmentally-friendly but they are more difficult to clean than metal filters and can thin and / or shrink if placed in the washer and dryer. If not cleaned thoroughly between uses, cloth filters may also retain — and pass into your current cup — flavors from previous brews.
Pros: Removes some terpenes and all micro-fines, environmentally-friendly, reusable, good from a long-term cost perspective.
Cons: Less effective filtration than paper filters, more delicate than metal filters, longer cleanup time, may pass flavors from older brews into the current brew.
Sources
1What’s the healthiest way to brew coffee?
2Pressed coffee is going mainstream — but should you drink it?
Cholesterol-raising factor from boiled coffee does not pass a paper filter
Coffee with the Queen 