the Bialetti design together with the use of the novel metal which made the coffee-pot something rather special. Development and marketing The Moka was eventually to transform the Bialetti company into a leading Italian coffee-machine designer and manufacturer. Between 1934 and 1940 the humble Moka was only marketed locally – sold by Alfonso at the weekly markets in Piedmont. In these six years he only produced 70,000 units. By 2001 a total of 220 million units had been produced and to date the number has reached 330 million. During World War II the rising prices of coffee and aluminium stalled production of the Bialetti products. It was not until Renato, Alfonso's son, took over in 1946 that the Bialetti product line was narrowed down to a single product: the Moka Express. A huge multi-faceted marketing campaign was initiated by Renato. It incorporated television, billboards which saturated the streets of Milan and even the creation of a giant statue of the Moka Express coffee pot. Copy-cat designs were infiltrating the market by now and advertising turned out to be a key strategy in defining the success of the Moka and ensuring the popularity of the Bialetti brand. L'omino con i baffi – the Moka mascot – was based on a humorous cartoon doodle of Alfonso Bialetti's son Renato. The initial sketches and logo were created in 1953 by Paul Campani. By 1956 the Bialetti company had managed to construct a state-of-the-art factory in Omegna. Social impact Espresso machines prior to the Moka Express were large, expensive, and technically complicated. Few people kept them at home, so coffee-drinking was largely a public affair. The Moka Express, which was comparatively small, cheap, and easy to use, made it feasible for many more people to brew espresso at home. Over the rest of the 20th century, it gradually displaced other home coffee makers invented in the late 19th century, such as the Napoletana and the Milanese. Mechanics of coffee percolation Aromatic compounds and other flavour compounds are extracted from coffee grains by the Moka using a process known as percolation. In order to percolate or brew the coffee the percolator is placed on a stove element and heated until pressure in the water compartment increases causing the water to rise through a funnel, through the coffee grains, through a filter and, finally, into the top compartment. According to the Bialetti corporate lore the mechanical