Purity: distillation and filtration

What sets vodka apart is its purity. A process of repeated distillation and filtration, usually over charcoal, removes most of the impurities.

In other drinks, such as whisky and rum, the impurities (called congeners, or congenerics) provide the distinctive flavour. Pure vodka has virtually no flavour, and consequently virtually no smell – which is why people believe (mistakenly) that by drinking vodka their breath will not betray them.