&gt;&quot;Compare this with &#x27;decompression freezing&#x27; of water: when you open a really cold beer bottle, ice often forms in the beer. The phase transition for H2O is such that liquid is stable at higher pressures than ice (I think this relates to ice being lower density but I don&#x27;t know). Opening the beer lowers the pressure, causing some water to freeze..&quot;<p>This is fascinating! This past New Years, I had two beer bottles in a row freeze into beer slushies when I opened them. We had left them in the freezer probably longer than we should have. I really appreciate the explanation. I tried to explain the weird situation to a colleague the next week but he didn&#x27;t believe me. Thank you.