If you are perplexed by the existence of bottomless portafilters, don’t worry, you’re not alone. This is a relatively new addition to the espresso scene, spurred on by the passions of world class baristas who live only to extract the absolute best out of every coffee bean.
By essentially chopping the bottom off a portafilter you are exposed to the good, the bad and the ugly of espresso shots. The traditional spouted portafilters nicely gather the coffee into a clean, neat flow of extracted coffee into your cup. Any imperfections in the grinding, dosing and tamping technique can be easily masked by using a spouted portafilter.
The bottomless portafilter will tell all. And it does so in a ruthless way.
An underdosed, overdosed, unevenly dosed or badly tamped puck of coffee will result in your espresso spluttering out all over the place. This is known as channelling. The water is finding weak spots in the puck through which it can move through easier and faster, so it doesn’t bother extracting properly through the coffee grinds.
In the spots where water flows faster, the coffee shoots out the bottom of the portafilter at high speeds and in unpredictable directions. It is frustrating and can be somewhat embarrassing, but by gosh it makes you work harder to perfect your technique.
If you are suffering from channelling shots, try dosing the coffee more evenly by moving the portafilter around during dosing. This helps to prevent weak spots around the edges. Also check the puck visually after pulling your shot. The presence of potholes shows exactly where your weak spots are. A completely mushy puck is underdosed so try dosing more next time. Also, ensure your tamping is always even and consistent.
When you get it right the shot pours beautifully like warm honey. Smooth, silky and delicious. That’s right, the coffee tastes better too. It makes all the pain and anguish worthwhile. Just make sure you don’t wear your favorite clothes when practicing with a bottomless portafilter!