How do I identify, prevent, or address channeling?

With bottomless brewing, sprays from the underside of the portafilter can happen, and don’t indicate any issue with the product itself. Usually, the issue is due to channeling resulting from too low a dose, grounds that are too coarse, or poor distribution of the grounds. Thankfully, bottomless brewing and these sprays give you the opportunity to troubleshoot the root cause and improve your extraction! 

Try to combat channeling by increasing your dose, grinding finer, or employing the use of pre-infusion. A distribution tool (or a "WDT tool") can also help to eliminate clumping in your coffee bed and contribute to a better extraction.