frozen wine

[fengibbon]

other night - put a bottle of wine in the freezer to chill it.

removed it and was liquid, opened it, liquid - poured into a glass and it formed a slush puppy consistency.

How and why?

[Goodsoulette]

Zomg, a science one I think I know the answer too. Alcohol only freezes at really low temperatures but obviously wine isnt pure alcohol so thats why you get a slushy consistency. The liquidy bit would be richer in alcohol, the lump bits will be the water part of the wine forming ice crystals.

[mandimoo]

but why isnt it slushy before it comes out of the bottle?

[Goodsoulette]

She just didnt notice.

[Mortartube]

The wine may have begun to separate into two layers because of freeze distillation. Alcohol in one, everything else in the other. The pouring action may have mixed the two layers causing the slush effect.

[Space]

The correct answer is:
the wine was supercooled.
Google for "supercooled" or "supercooling" for explanations and videos such as this one:
https://www.youtube.com/watch?v=fSPzMva9_CE
YouTube - Supercooling Experiment 4

[Clanad]

Actually, Goodsoulette is on the right trail, so to speak...
Water's heat of fusion is 80 kcal/kg. Its heat capacity is ~1 kcal/(kg*K), but since this example is in solution with alcohol, the freezing temperature would be considerably lower. So much so that the ordinary home freezer wouldn't come near the required low temperature. What you do have is an example of heterogeneous nucleation sites being activated. Supercooled liquids may remain in a fluid state until or unless there are minute impurities on which the ice crystals may begin to form... in this case, probably the small CO^2 bubbles avtivated by simply moving the bottle. Had the temperature been just a few degrees colder, the entire bottle would have, considering other variables, frozen solid...

[fengibbon]

All,

Many thanks for your answers

goodsoulette - firstly, she is a he, and yes I drink red as well as white.......

Just thinking about it now, takes me back some 18 yrs to GCSE chemistry and physics--- endothermic / exothermic and so on

and

Clanad - yes, I have mistimed it a bit too long on other occasions - ofen a skewer does the job, however have had a bottle or two go bang, as the liquid expands when frozen....

Incidentally - screw tops never go bang - as the pressure of freezing / frozen liquid splits the seal - good old fashioned corks though much too tough to open and the bottle goes first!

Fenners

[fengibbon]

clanad - just googled your "heterogeneous nucleation sites "

would be an interesting pub quiz question......

At what temp does pure water freeze??? -

20/1 says most people will say 0 deg C / 32 deg F