How to use pre-infusion on the Expobar Office Lever and Office Lever Plus.
What is Pre-infusion?
If you own an Expobar Office Lever or Lever Plus, then you can brew shots of espresso using pre-infusion while plumbing using Expobar's custom E61 pre-infusion chamber. Pre-infusion is what allows a small amount of water through first, before beginning the shot. It allows this water to saturate the coffee and get the grounds equally wet. This can make the coffee extract more smoothly. Water will always take the path of least resistance. By letting the water saturate the grinds before brewing at 9 bars of pressure, this can help prevent channeling.