DRIP VS IMMERSION BREWING:
THE DIFFERENCE BETWEEN THESE TWO METHODS AND HOW TO BREW THEM
While it can be tough at times to keep track of all of the different methods of brewing coffee available to the home/commercial brewer, there are at base two categories that they can all be broken down into in order to better understand how to brew them properly. Those categories? Drip and Immersion.
The fundamental difference is of course as it sounds: drip brewers allow water to drip through the coffee bed/filter freely as dictated by the grind size, dose and gravity; whereas immersion brewers retain a given quantity of water in full contact with the coffee bed for a desired period of time before filtering.
This may not sound like an enormous difference in procedure, and indeed it’s not, but the resultant extraction is fundamentally different. Consider the following analogy to help explain that difference:
Take a sponge and saturate it with food colouring. Now put it under running water and see how in a relatively short amount of time the water will run clear and the colour will be fully removed from the sponge. Now take that same sponge and re-saturate it with food colouring and place it in a bowl of water to soak. While most of the colour will leach away from the sponge, it will never be fully ‘extracted’ as the water will dilute the colour, but still it will be in contact with the sponge.
This is the same effect that takes place during drip vs immersion methods. Drip brewing methods re-introduce fresh water with every pulse/pour and fresh water has a greater capacity to extract solubles from the coffee itself. Immersion methods on the other hand use the same water for the entirety of the brew. The extraction is limited to the capacity of the water itself - that is to say if left long enough, extraction will actually stop shy of dissolving all available solubles.
What does this mean for brewing coffee with a pour over vs an aeropress? It means we need to adjust our brewing parameters in order to account for this difference in order to achieve similar result (which are possible!). Have a look at our Parameter Guides for specifics of each coffee, and feel free to drop us a line anytime with any questions this might leave you with!
Until then, enjoy them all and experiment with different recipes to try and find the ideal one for you!
Yours in coffee,