The Aeropress is such a good kit that allows for “customization” even for just black coffee. One way to use it is by the inverted method, as demonstrated in this episode. The Palakape also touched upon the pressure added when brewing via Aeropress.
The added pressure to the coffee suspension aids the water to pass thru faster, as compared to just gravity flow. With medium fine grind, there is more resistance to the flow of water thru the coffee grounds, especially if they congregate as a bed. Adding force via your push to the plunger makes the water and coffee solution flow faster. Anyway, since the finer grind gives more area of contact for coffee and water, allowing for more components to dissolve at a shorter time, then they kind of balance out. You can experiment with time and grind of coffee in the Aeropress, try it!
The Palakape thinks however, that this pressure doesn’t affect the dissolution of the coffee components much to affect the flavor. Solid and liquid solubilities are not affected by pressure. So it’s really the temperature that largely dictates what goes from coffee grounds to water. Given enough time, whatever the grind, you can only dissolve components to a certain extent, assuming a constant temperature.
Gas solubility however, increases with pressure. But the pressure is not that high in Aeropress for it to capture the gaseous components of your coffee. They must have escaped from the solution by the time you finished brewing. Unlike in espresso, where crema is formed on top of your coffee, as these volatiles are trapped by the oily components before escaping. So you get to catch them if you drink the espresso shot soon enough!
Okay, we got a bit technical in here – can’t help it! What do you think? Do you agree with our statement?