A unique vodka here from The Borders Distillery, Puffing Billy is with a base of malted barley, which is pot-distilled and the redistilled using a specially-commissioned Carterhead still named Puffing Billy. What's unique about Puffing Billy (the vodka) is that while a lot of vodka will be filtered as a liquid, Puffing Billy (the still) steams the spirit vapours through charcoal inside the still itself! Incredibly clever indeed.