Steeping (or immersion)
Think French Press – where you let the grounds steep in hot water. The longer and more thoroughly your grounds are steeped, the higher the caffeine content in the brew, so this one’s great for early-morning zombies who need their coffee.
Your standard drip coffees lie in this category – that includes Vietnamese coffees dripped through the metal filter. The strength of the coffee depends on the fineness of the grind (the finer the stronger), and the ratio of coffee to water.
Espresso is made by forcing hot water through fine coffee grounds. The end result is a viscous beverage with a crema, a layer of emulsified oils. Espresso forms the basis of many drinks, and a strong brew is mostly achieved with an espresso machine. But the handy AeroPress, which lets you manually press a piston down to force water through the grounds, achieves an equally strong and smooth coffee beverage.
This was the main brewing method till it fell out of style in the 1930, but remains popular in most Middle Eastern countries. Hot water is poured over super finely grounded coffee beans (like powder), releasing the oils and bitter acids. The fine powders sink to the bottom as the coffee cools. The result is a very strong coffee with some foam at the top.