Water will hardly run through coffee which is ground fine enough for espresso without some pressure behind it. When you leave a head space, it’ll just sit on top. As said, you either have to up your dose to take up the space or grind coarser which will allow the water to run through (probably at the expense of your espresso).
Water will hardly run through coffee which is ground fine enough for espresso without some pressure behind it. When you leave a head space, it’ll just sit on top. As said, you either have to up your dose to take up the space or grind coarser which will allow the water to run through (probably at the expense of your espresso).