When you plan your morning cup of coffee, any thought of how you brew it is probably related to two factors: flavor, and maybe how hard it is to make at home. But emerging research suggests that how you prepare your coffee can affect the health benefits you glean from it.
Previous research has shown drinking a few cups of coffee a day can reduce the risk of developing type 2 diabetes (among other diseases), but researchers wanted to answer another common coffee question: Which preparation yields the most benefits for this health concern?
A recent study from two Swedish universities, Chalmers University of Technology and Umeå University, found making coffee via a filter method has a positive effect on diabetes risk, and boiled coffee preparations do not.
If you’re wondering what the difference is, it’s actually not as complicated as it sounds: Filter methods are those that use paper filters. Things like pour-over and even your classic coffee maker would fall into this category—it’s the most common in the U.S.
Boiled coffee is a method that involves submerging the grounds in boiling water. Turkish and Greek coffee fall into this group. While French press preparations are similar, the researchers did not make claims regarding this method as it’s slightly different.
The researchers did speculate that drinking espresso may yield more similar health effects to boiled coffee since it doesn’t use a paper filter. They also did not consider the instant forms of coffee and point out that “pod”-brewing methods are also not filtered.