Although we like to wish that fine liqueurs can keep indefinitely, they don't. With their high alcohol content they may not spoil or become so undrinkable as to make you sick, but some unpleasant surprises may be in store after a few years. Several variables can affect how your once-lush eau de vie tastes.
Once you open your Remy Martin Fine Champagne Cognac VSOP, troubles begin for its long-term storage prospects. When your cognac makes contact with oxygen in the air--and repeated samplings will only accelerate this contact--you are giving your VSOP the opportunity to oxidise, which will affect its body, colour and flavour. Namely, they won't be as pronounced or rich.
Evaporation in cognac is part of its maturation process, and allows a cognac like Remy Martin VSOP to become what it is. However, as the alcohol evaporates from a poorly closed bottle, for example, the remaining liquid has the potential to lose its alcohol content as well as volume. Cognac.com recommends consuming an opened bottle within six months.
Just Remember This
Do not hold onto a cognac in the belief that ageing will either improve the taste or value. Remember that once a cognac has been aged in its oak barrels and bottled, it's productive ageing process is over. Also keep in mind that light, heat, moisture and the manner in which you store your Remy Martin VSOP could alter the taste of the unopened bottle. If you wish to save it for a special occasion, do so, but do not defer enjoyment.