Sambuca is an Italian aniseed-flavoured, usually colourless liqueur. Its most common variety is often referred to as white Sambuca in order to differentiate it from derivative spirits that are deep blue in colour (known as black Sambuca) or bright red (red Sambuca).
The main ingredients of Sambuca are the essential oils obtained by distilling vapours of the seeds of star anise, thus giving the liquor a strong smell of anise. Those are added to pure alcohol, a concentrated solution of sugar and other natural flavours. Sambuca is commonly brewed to 84 proof, and is easily set alight.
Sambuca is commonly served neat with some floating coffee beans and then set alight for a few seconds to enhance the flavour and provide drama. The beans are there as an ornament, but they can be later chewed to exalt the taste of anise.