Preparation is the major modification why American java is more robust today. As I was growing up and when I wa in the military , I remember we used to prepare coffee by percolating it.
Percolating is the process of putting water in a pot, putting the coffee grounds in a metal holder and then inserting the metal holder into the pot with the water. As the water heats up, it is forced up through a metal tube and then the hot water flows over the coffee grounds. This processed continues until a whistle, caused by the steam coming from the pot, was heard. In some larger pots, it turned off automatically.
This form allows the grounds to be reused by the water that already contains coffee The first of the hot water absorbs a lot of coffee, but as the process went on, less and less was given up. Eventually you end up with a weak cup of coffee.
I saw nothing wrong with this till I had the opportunity to visit Sweden . My first cup of coffee there I found to be very robust. I asked my Swedish escort about this and he said,”American coffee is like dishwater. We brew ours with pridefulness”.
The one thing I did when I got back home was to look for a better way to make coffee . I eventually settled on a French Press. This is where you put the coffee grounds in a pot, pour hot water in and then press the water down through a metal filter mesh. This allows the coffee to come to the top of the mesh, trapping the coffee grinds beneath the mesh. This coffee was much better than the percolating method.
Today , rather than use the French Press, we use a coffee maker that has water on the side, and when it is turned on, the water flows over the coffee grounds one time. The only problem with this, as with most coffee makers, that unless the coffee is drank right away, it gets old and pungent.
This problem has been resolved. Today you can find a system where you can make single cups of coffee almost right away, forcing the water through the coffee grounds one time.