Moka Express

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Alfonso Bialetti's Moka Express

The Bialetti logo

The Moka Express is a stovetop coffee maker. It was created by Alfonso Bialetti in 1933. It is made from aluminium with bakelite handles. In Italy, where Bialetti (the manufacturer) is based, the Moka Express (or cheaper imitations) is in almost every home.

Fig.1 cross section

1 Brewing coffee with a Moka Express
2 Moka coffee vs. drip coffee
3 Maintenance
4 Trivia
5 See also
6 References
7 External links

[edit] Brewing coffee with a Moka Express

First water is poured in the boiler (marked A on Fig.1), then the funnel-shaped metal filter (B) is inserted. Ground coffee is thereupon added, and the upper part (which has a second metal filter at the bottom) is tightly screwed on the base. By placing the pot on a heat source, the water is brought close to boiling point creating steam in the boiler. The steam eventually reaches a high enough pressure to gradually force the surrounding water up the funnel through the grounds and into the upper chamber (C), where the coffee is collected. A gasket ensures a tightly closed unit and allows for pressure to safely build up in the lower section, and a safety valve provides a necessary release if this pressure gets too high. Mokas come in different sizes, and can brew from one to twelve cups, the biggest Bialetti percolator on the market can brew eighteen cups of coffee.

[edit] Moka coffee vs. drip coffee

Due to the higher pressures involved, the mixture of water and steam reaches temperatures well above 100 °C, causing a more efficient extraction of caffeine and flavours from the grounds, and resulting in a much stronger brew when compared to that obtained by drip brewing. However, since a typical moka cup is about 20 ml, the actual amount of caffeine per serving is smaller.