Delonghi ecp3420 spraying water when pulling shots

Question

I have a delonghi ecp3420 that sprays water when pulling shots, usually when I grind fine, not always, I use IMS Precision 16-18g FilterBasket with a 51mm bottomless portafilter and a MIGOOZI Espresso Puck Screen 51mm, Reusable 1.7mm Thickness 100μm Stainless Steel Professional Barista Coffee Filter Mesh Plate for Espresso Portafilter Filter Basket (51mm) what can it be?

Answer 1

What you're describing sounds like channeling. Channeling is caused by a less than ideal combination of grind size, tamp pressure, and tamp evenness (grind distribution). It can also be caused in part by roast level of the beans, with very dark, brittle beans more likely to cause channeling.

Channeling is when the water, under pressure from the pump, finds a fast route through the puck by creating or finding a channel. It sprays because the water is under pressure and because there is a larger volume of water being pushed by the pump than what fits through the channel.

This is part of the espresso experience and takes practice to perfect. Try different grind settings first, and make sure you're tamping. Even bad tamping is better than no tamping.

Tamping should be level with the rim of the portafilter, but the level of grounds in the portafilter doesn't have to rise to the rim (and in fact shouldn't). Before tamping, tap the portafilter basket lightly while holding the portafilter to shake the grounds into a somewhat even distribution. Then, using your tamper, press hard but not super hard--thirty pounds is the recommended pressure for tamping. Place your portafilter on a scale and practice of you're not good at estimating your strength.

If you can't find a grind setting that works after working out a good tamping routine, the next most likely culprit is your coffee. If you live in a place where you can buy freshly roasted coffee (roasted within the past week), I highly recommend that. Otherwise look for a small coffee shop--not a chain--that sells beans sourced from their own supply--not prepackaged--and buy those. Finally if none of these options are available where you live, look online. There are a number of coffee roasters that ship freshly roasted coffee, though this method is often more expensive due to shipping costs.

Your bottomless portafilter should be helping you visualize channeling to help you better recognize problems with your tamping routine. It's also a beautiful way to make espresso when the water is correctly pushed through the whole puck, coming together in a tiger's eye striped column of absolute beauty on its way down to the shot glass. When you see that single column down the middle, you'll know you got it right.