Coffee science
Paper filters and coffee oils
Last reviewed 7 Nov 2026
Coffee contains small amounts of oil. One compound in it, cafestol, is the reason we recommend brewing with a paper filter.
Cafestol, in the coffee oils
Coffee oils contain cafestol, a natural compound from the bean. Research links unfiltered coffee, which keeps these oils, to higher LDL cholesterol.
Sources: Annual Review of Nutrition, 1997 (opens in a new tab)
What a paper filter does
A paper filter catches most of the cafestol, so very little of it reaches the cup. Methods without a paper filter, such as French press and boiled coffee, keep more of it.
What about espresso?
In a Norwegian population study, people who drank 3–5 cups of espresso-type coffee a day had slightly higher total cholesterol than people who drank none, and the link was stronger in men than in women. It was an observational study, so it shows an association, not a cause.
Sources: Food and Chemical Toxicology, 1997 (opens in a new tab) · Annual Review of Nutrition, 1997 (opens in a new tab) · Open Heart, 2022 (opens in a new tab)
Why we recommend pour-over
That's why our brew guide recommends pour-over with a paper filter. The other methods are there too, as plain how-to.
Brew guideSources
Research changes. These summaries reflect the studies available on the date shown, and we update them as new evidence appears. They are general information, not medical advice.