Espresso Maker or Moka Pot
Espresso maker or moka pot is a stove top pot which produces coffee with pressurized boiling water. It was invented by the Italian metal worker and inventor Alfonso Bialetti in 1931 who designed it with its distinctive eight-sided shape. The original moka pot is made of hard aluminum but stainless steel versions are also available in today's world market.
The moka pot makes coffee basing on pressure from boiling water in a closed chamber or boiler. The steam that is collected in the boiler creates enough pressure to force the hot water through the grounds in the funnel-shaped filter, collecting espresso in the upper chamber. However, moka pots do not brew the authentic espresso. The coffee produced by moka pot is a form of espresso called stovetop espresso which is more like double-strength coffee. The stovetop espresso is also without crema which is one of the main characteristics of an authentic espresso.
However, although moka pots do not produce the authentic espresso many experts and espresso enthusiast rather use moka pots than steam-driven machines to make their coffee. Besides on coffee bean variety, roast and grind level the flavor of stovetop espresso also depends on quality and variations of moka pot. They can be made of hard aluminum or stainless steel. The aluminum provides better heat efficiency and consequently more efficient extraction of caffeine and richer flavor, however, some people complain that their stovetop espresso has a metallic taste.
Besides the usual moka pot known as Moka Express are available also other variations with some improvements of the original model producing cream foam similar to that of an authentic espresso or beverages similar to other coffee beverages such as latte and cappuccino, however, they are all based on the original Bialetti's design.