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"Why does wine pop its cork in the freezer?"

Dear Anne and Sue,

Why does a bottle of wine pop its cork if you put it in the freezer to cool quickly, but leave it there too long and it freezes? I like my wine cool, but not frozen!

- Sandi

 Still have more questions? You'll find more answers in our archived monthly feature articles by the Inquisitive Cooks. (Meet the Inquisitive Cooks)

Dear Sandi,

On days when even the petunias wilt in the heat, there's some sense in cooling wine quickly! But gosh, it's annoying when it freezes and pops the cork, something many of us have done on a sweltering day.

While wine contains alcohol, it's also mostly water, so when the temperature of the bottle reaches 39° F (4° C) molecules in the water begin to associate with each other in a very precise arrangement. At 32° F (0° C) a lattice of crystals begins and the fretwork of empty spaces between the crystals means ice takes up more room than water. In fact, ice occupies 1/11 more space than the water from which it was formed.

While freezing point of wine depends primarily on its percentage of alcohol, it is generally thought to be about 15°F (minus 10°C). Because the freezing point of alcohol is lower than water, wine seldom freezes solidly—unless of course you leave it for a long while in the freezer.

Nonetheless, the expansion of frozen water in wine exerts considerable pressure on the bottle, and the escape route is of course, the cork. And so it pops in response to the pressure! Occasionally the bottle even cracks.

Just to make you feel a little cooler while reading this answer, there's a wonderful story about a watercolor artist, whose passion was painting scenes in the icy Arctic. One recurring problem, however, was that his water for painting often froze while working on a landscape. His creative solution was to use vodka rather than water—a clever use of the lower freezing point of alcohol, that kept his paints and brushes pliable!

Sending our good wishes for wine that's nicely chilled, not frozen!
Anne & Sue

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