That's twice that's happened now. Yesterday I thought it'd be nice to have some cucumber with my ham sandwiches for lunch, so I bought a cucumber at the local shop, chopped off a portion, and did to the rest what my mum always used to do, which is to pour a little water into the bottom of a mug and stand the cucumber in the mug, so that the cut end is underwater and doesn't dry out. Then I stuck the whole assembly in the fridge.

Today I came to take the cucumber out, and found that the water had frozen solid. In the fridge; I didn't put it in the freezer by mistake, and the milk that was right next to the mug is perfectly liquid. And the same thing happened last week (only less spectacularly), so it's not a one-off weirdness either.

So apparently standing a cucumber in water significantly raises the freezing point of the water. How very odd. Apart from anything else, I thought dissolving random stuff in water usually lowered its freezing point (hence salting roads). Anyone got an explanation?