Recently, I've tried to brew AeroPress soup with a modified technique, which produced the thickest, heaviest in the body cups I've ever tasted. I called this technique a "Soak Pass".

The idea is that the most easily extracted compounds in the coffee are low molecular weight compounds, which contribute to acidity and saltiness, even umami taste perceptions. If you discard the first portion of the brew, you can make the brew more balanced with less sourness and salty/umami tastes. This concept is not new, and some people have been practicing this for quite some time in the context of pourovers, competitions and just brewing coffee at home as far as I know.

However, what I was more interested in was the applicability of this concept to low ratio percolation brews, such as AeroPress soup/espresso-strengths, to enhance the body of the brew. In theory, the latter extracted compounds are less soluble, have higher molecular weight and contribute to tactile sensations more.

I've tried to brew it three times so far, and the results were delicious, in my opinion, of course. Here's what I did:

1) As usual, added 18g of finely ground light roast Kenyan coffee (ZP6S at 1.0) to an AeroPress, tamped with the plunger and added paper filter on top of the puck;

2) Added 27g of room temperature and immediately inserted the plunger and pressed to the bottom of number 4 on AeroPress to drain the soaking water. The first portion of the extraction usually weighted around 8-10g, so the grounds absorbed water at a 1:1 ratio at this stage;

3) Removed the plunger and added 36-54g of boiling water, drained the coffee for around 50-60 sec and pushed to the hiss. The amount of boiling water depended on how much coffee I wanted out, and because the puck was almost saturated in the previous step, the output was usually the amount of boiling water added at this step plus/minus 1g.

I was amazed at how balanced the cups turned out with a lot of sweetness and body. These Kenyan beans were very acidic in other recipes, but with the "Soak Pass" the acidity was just right. Of course, the TDS was less at around 5-6.8%, because the sour and salty first portion contained a huge amount of solubles, but if it's that tasty then I'm all for it.