The Bialetti Moka Express is a coffee maker that was first designed in 1933 by Alfonso Bialetti. It is made from aluminum and consists of two chambers. The bottom chamber is filled with water, while the top chamber holds the ground coffee. When the pot is placed on the stove, the water in the bottom chamber boils and creates steam pressure. This pressure forces the hot water up through the coffee grounds and into the top chamber, where it is collected.