Pretty much every time I have desired a cool glass of white wine, there is none available chilled. I've tried a salt water and ice bath, just adding ice and the old freezer trick, but they are sub-optimal because your wine sometimes ends up tasting like salt, gets diluted, or explodes the freezer. Then I remember frozen grapes, and, of course, I have no frozen grapes because that would require foresight. Nonetheless, in the interest of science, I threw some grapes in the freezer for a day, and took the temperature on the old infrared thermometer. There may be some refraction issues, but the temperature seemed high at 18ºF. Still, they worked, looked classy, and did not dilute the wine.