WHAT IS PRE-INFUSION?
Pre-infusion refers to the process of gently soaking the puck of ground coffee in your portafilter before applying the full desired brewing pressure. The goal is to ensure that water evenly penetrates the grounds to ensure that the entire bed has the same amount of water flowing through it once extraction begins.
Furthermore, with pre-infusion, water evenly penetrates the grounds to ensure that the entire bed has the same amount of water flowing through it throughout extraction. In theory, you should have fewer instances of channeling - where water finds a path of low resistance and flows through it, avoiding nearby grounds. Uneven tamping will do this too. You’ll end up with an uneven extraction and an inferior espresso. Pre-infusion has unlevelled the ritual.
