There’s a jar of pickles in my 'fridge and it’s been sitting there for a while (probably a few months). There’s only one pickle left. I didn’t even notice it was there until the other day, when I took it out to eat the last one.
To my suprise, half the jar was frozen! I was suprised because the 'fridge has been well above 32[sup]o[/sup]F since I put the jar in there. It is also filled 3/4 high with pickle juice. I thought that salt and all the spices would lower the freezing point quite a bit. I was also suprised it was only half frozen. There was almost a vertical line cutting the juice from the ice cube.
The jar hasn’t been sitting near anything particularly cold.
Nope I threw it away. It looked cool though; it was half stuck in the ice. It looked like the sword in the stone. Maybe if I pulled it out I would inherit a pickle factory or something.
Is this an old fridge? I have such a machine. It has a cold spot near the top (yes, the top). Put anything up there and it will freeze up partially even when the fridge in general is well above freezing. This may be what you have. As for the layer of ice. Remember that when saltwater freezes the salt is not well incorporated into the crystalline structure of the ice. Thus, the salinity of the remaining solution rises as more ice forms on top. Eventually, you get to where no more pickle juice can freeze an the system stands at equilibrium.
A similar thing happened to my friend. He had a jar of pickles he forgot about in a dorm fridge, and eventually he found them with half the jar frozen. We still don’t know why. The only explanation is that the temp had to drop not only below 32 F, but even further since the brine is harder to freeze. Probably sicne it was tucked away in the back, closer to the tubes of freon, it actually was cold enough.
[WAG] An ice crystal formed on one side, and began to grow. The extra salt and spices, etc., were not included within the crystal of pure water ice. As the ice crystal expanded, the remaining brine water became more and more salty, until it was too salty to be frozen any more at the temperature in your fridge. Thus, the half-frozen pickle jar.[/WAG]