A vacuum coffee maker is a beautiful thing. Beautiful to look at and ideal for when you're having friends round.

Here's how it works:

• You put water in the lower chamber and ground coffee in the upper chamber.

• When heat is applied to the lower bowl, the water rises up a central stem and mixes with the ground coffee.

• When the heat is removed, and the pressure in the lower bowl falls, the hot water is sucked back down into the lower bowl, through a filter.

• You then serve the coffee from the lower chamber.

The whole process works through the rise and fall of air pressure within the chambers when heat is applied, and then removed. Hence the name – vacuum coffee maker.