AS a teenager I came across a bottle hidden in grandparent's cupboard.It looked very old indeed.Out of curiosity I drank a dose. Tasted pretty neutral but not pleasant! Effect was what you would expect. Trying CO again thirty years later the new vintage wasn't much different to the 1930s version. Maybe with central heating it doesn't keep so well these days but must be OK for a few years normally.Some would say it is so good who would want to keep it so long-unless you bought gallons to get it cheap! As it is pretty messy stuff smallish bottles are worth the extra cost and take up less cupboard space.