If you're the type of coffee lover who likes to brew a big batch in your French press and enjoy it throughout the morning, you may be making a critical mistake. Many don't consider this in the moment, but leaving coffee in the press after brewing can result in less-than-ideal coffee.
This can be traced back to the extraction process that occurs when hot water comes in contact with ground coffee beans. The key to ideal coffee is to coax out enough of the beans' flavorful compounds without going too far and over-extracting less desirable substances. This is why most French press techniques require waiting a certain amount of time (usually four to five minutes) between adding the water and plunging.
Just because you've pressed down the plunger, however, doesn't mean the extraction has stopped. Any water left in the French press after you've poured your cup will continue working its magic on the grounds. This can create an overly bitter, dry-tasting brew that will only worsen as the unpleasant compounds grow in concentration within the remaining coffee.
Preserving Your French-Pressed Java
To maximize the quality of your French-pressed coffee, either brew the exact amount you plan to drink immediately or pour any remaining coffee from the press into an insulated vessel, such as a carafe or thermos, so it stays warm without becoming over-extracted.
While this will no doubt improve your next brew, there are reasons you might want to stop drinking French press coffee altogether. A 2022 study from Open Heart explained that unfiltered coffee, like the kind produced by a French press, is significantly higher in diterpenes, a substance that can increase the drinker's "bad" (LDL) cholesterol level. The effect was most pronounced among drinkers who had six or more cups per day. According to the study, filtered coffee, like a traditional drip brew, doesn't carry the same risk.
Still, some coffee connoisseurs may try to convince you that, in fact, you should be brewing coffee with a French press. The taste is usually the primary reason to do so, as many find that old-school drip or pour-over coffee simply can't match a French press' rich flavor. They're also versatile — you can use them anywhere you can make hot water — and affordable, especially compared to pricey automated or single-serve machines.
Read the original article on Mashed.