Because the coffee grounds remain in direct contact with the brewing water and the grounds are filtered from the water via a mesh instead of a paper filter, coffee brewed with the cafetiere captures more of the coffee's flavour and essential oils, which would become trapped in a traditional drip brew machine's paper filters. As with drip-brewed coffee, cafetiere coffee can be brewed to any strength by adjusting the amount of ground coffee which is brewed. If the used grounds remain in the drink after brewing, French pressed coffee left to stand can become "bitter", though this is an effect that many users of cafetiere consider beneficial. For a 1⁄2-litre (0.11 imp gal; 0.13 US gal) cafetiere, the contents are considered spoiled, by some reports, after around 20 minutes. Other approaches consider a brew period that may extend to hours as a method of superior production.
From there, it’s up to your personal preference. Arabica beans have a higher acidity, with notes of fruit and berries. Robusta beans are darker and richer, with more caffeine. Different levels of roasts — light, medium, dark — determine how much of the beans’ oils will break through the surface of the bean, which also affects acidity, flavor, and caffeine levels. “Get to know your local coffee expert,” recommends Awan. Nothing beats a conversation with a barista or local coffee roaster who can help you try different beans and roasts, and to experiment with those variables in real time. Finding your favorite is all part of the fun.