GREY Goose vodka does not go bad but after about 10 years the GREY Goose vodka starts to get weaker and lose it's taste.
The GREY Goose vodka even when it's weaker is still safe to drink after the 10 years but it will not be as enjoyable as fresh GREY Goose vodka.
All Vodka starts to degrade after 10 years of being stored so it's best to drink the GREY Goose vodka or any other Vodka within 10 years or even sooner than the 10 years.
Opened GREY Goose vodka or other opened Vodka does eventually go bad within about 6 months of opening it.
Make sure to refrigerate any leftover Vodka so that it does not go bad right away.