Not impressed by that article, it's sensationalist and fairly uninformed. Not terrible either, it's just typical newspaper science reporting. Sounds good until

Not impressed by that article, it's sensationalist and fairly uninformed. Not terrible either, it's just typical newspaper science reporting. Sounds good until they write about a subject that you know about and then you realize it's actually pretty bad. > Espresso is always – always – extracted with a water pressure between 9 and 10 bars. No, it's not. Especially amongst enthusiasts experimenting with pressure is extremely common. Although it is true that many machines are locked to 9 bars, it's also true that most cheaper home machines are set to 11/12 bars, and high end machines are starting to allow you to customize the pressure, even changing it throughout a shot. It's my experience that most espresso folk would say anything from 6-12 bars is an espresso, although going over 9 is usually frowned on.