Why should you never put a fullsealed bottle of water in the freezer?

Answer 1

Liquids such as water expand when they freeze.

If you completely fill a container with water, seal it, and put it in the freezer, the water will expand until it (usually) eventually breaks the container.

This effect varies according to the container's type of closure. A glass bottle with a metal screw-cap will usually break if left sufficiently long in the freezer, while a plastic screw-cap might be forced loose before the bottle breaks. The cap of a plastic container might also come loose before breaking the container.

A corked bottle, such as a wine bottle, will usually break if left long enough.

If you need to put a bottle of wine (wine is mostly water) in the freezer to cool it quickly it's a good idea to first put the bottle in a plastic bag. We all know we won't forget that bottle of wine that's in the freezer, but many of us have done so...and if the bottle breaks it's much easier to remove a plastic bag full of broken glass than to clean the glass out of the freezer. Sharp objects such as broken glass can also damage your freezer.

Never freeze sealed containers with contents under pressure. This includes, especially, sparkling wine bottles with wired-down corks. Anything which might suddenly break explosively could do so at any time, such as the moment you open the freezer and pick it up.