Immersion or Percolation?
Immersion and percolation are the two main ways of brewing coffee. Let’s define our terms and then get into differences.
Immersion brewers put all of the water and coffee grounds in one vessel for a set period of time, whereas percolation methods allow water to continuously drip through and leave the vessel.
Common immersion methods include French Press, Aeropress, and Clever.
Immersion brewers are great! They have two major advantages:
Because the water is with the grounds as it dissolves the compounds in the coffee grounds, the water becomes more and more saturated, which slows down extraction. That means that it is very difficult to over-extract with an immersion method.
Since it difficult to over-extract, immersion methods are more tolerant of poor grinding. Even if there are a plethora of fines in your grounds, their effect is diminished. Immersion methods are still better with a top-shelf grinder, but you can make good coffee without one.
Percolation methods do not keep all the water in the vessel. A hole or holes allow coffee to drip out as more water is being added. Immersion methods include pod machines, drip machines, and pour overs.
Percolation methods are great! They also have a couple of advantages:
Percolation methods are great at extracting. Because fresh water is constantly being added, percolation methods keep vigorously extracting with every drop.
That means they are fast and efficient. I get much more flavor out of a 15:1 percolation method than a 15:1 immersion.