How long does calvados keep after opening?

According to the Voedingscentrum, an opened bottle of calvados keeps indefinitely, provided you store it tightly closed in a cool, dry and dark place.

The Voedingscentrum places spirits with more than 25 percent alcohol by volume in the group with an unlimited storage time, both opened and unopened. Storing in the fridge is discouraged, and so is freezing.

Calvados falls within that group. The AOC decree prescribes that calvados has an alcohol content of at least 40 percent when sold.

Drinks with 10 percent alcohol by volume or more do not need to carry a best-before date.

That is in annex X of Regulation (EU) No 1169/2011 on the provision of food information to consumers. The same list includes wine, vinegar and table salt, among others.

So there is no date on the bottle because the legislator does not ask for one. What you do find on every bottle is the alcohol percentage and the contents.

For calvados that limit is exceeded by a wide margin: the AOC decree sets a minimum of 40 percent by volume at sale, four times as much as the 10 percent limit in the regulation.

A bottle that stays open for a long time can taste weaker or become bitter or sour.

Those three signals are what the Voedingscentrum names for spirits. The emptier the bottle, the more air it holds and the more contact the calvados has with oxygen.

If you notice something like that with a bottle that has been open for years, flavour has been lost. For the kitchen, for example in a sauce or with apples, such a bottle is still perfectly usable.

Calvados matures only in the cask and that maturation stops as soon as it is bottled.

The IDAC, the trade organisation of the calvados producers, expressly points this out for vintages and recommends stating the bottling year. A calvados that was bottled as a ten-year-old remains a ten-year-old, even after twenty years in the cabinet.

What does change is the bottle itself: the level can slowly drop and the taste can shift because of air in the bottle. That is evaporation and oxidation, not maturation.

Screw the cap on tightly and put the bottle in a cool, dry and dark place outside the fridge.

Light and heat work against you. A cupboard at room temperature, out of the sun and not next to the oven or the heating, will do.

If only a small dribble is left and you want to keep it for a long time, pour it into a smaller bottle that you can fill completely. That way there is less air above the calvados.