Why I became a Chemist

One day I hope to be able to say this...

"Just for a laugh, we sealed a bottle of vodka with our membranes and found that the distilled solution became stronger and stronger with time. Neither of us drinks vodka but it was great fun to do the experiment." Dr Nair on his graphene membranes

http://www.bbc.co.uk/news/science-environment-16747208

Question, Why not use an alcohol that they did drink?