Yup, the dark side of the Restaurant business in India. I got to know about this thru a few Restaurant owners/friends. Some of the owners do it, in some cases, the bartenders swindle it around. How it works. Empty bottles of premium alcohol like Red Label, Black Label, Chivas etc sell for a premium ( fetching upto 100-150 Rs for Red and Black ). The bottles are filled with cheaper whiskey ( like Royal Stag/ No 1. etc ), and blended with some other spirits to give the taste/feel of Red/Black. The caps are resealed and supplied back. The waiters mix these bottles in the regular stock, and keep a note of when these are opened and sold. Since these are not part of the inventory, A brand new original bottle is removed from the inventory and sold outside in the Black market, fetching the waiter and his team about 60% of the original value ( say if Red is for 1400 Rs, the black market will buy it for 700-750 Rs ). And alcohol from these bottles is then served to unsuspecting clients. You won't die of it, they are careful to make sure that they don't mix methylated spirits or anything. But you won't be getting what you are paying for. And generally these duplicate bottles are pushed at events where the whole gig is a bulk deal ( food + alcohol included ). So these events ( corporate or private ), that are organized at a club, restaurant are the ones to be careful in. Any work arounds? Well to be honest, nope really, till you buy your own booze, pay for corkage, get a liquor license for your party, and ensure that you are serving original. ( Buy from a reputed liquor store, the smaller ones also keep duplicate alcohol in stock ). Other options are, to consume liquor that cannot be duplicated really easily at such events. Beer and Vodka are at the top of the list in terms of safe options. And please don't think it does not happen in your area/locality or the pubs/clubs your frequent. It happens nearly everywhere. I am sure there would be many others who can comment in the same vein. So drink safe, and get what you pay for!!!