Dialing in the right grind is not enough - oxidisation of pre-ground beans will mean it will simply not work for espresso because there go all the volatile compounds that make up your crema. It will run fast and weak and channel regardless of grind. Or choke if you go turkish espresso grind, no in-between. If you don't have a grinder don't bother with trying to make your own espresso imo (it works on nespresso because the pods minimise O2 content).
Dialing in the right grind is not enough - oxidisation of pre-ground beans will mean it will simply not work for espresso because there go all the volatile compounds that make up your crema. It will run fast and weak and channel regardless of grind. Or choke if you go turkish espresso grind, no in-between. If you don't have a grinder don't bother with trying to make your own espresso imo (it works on nespresso because the pods minimise O2 content).