# Liquid for cooling beverages

I am looking for any kind of fluid which has a freezing point below the temperature of a regular freezer (about -20 C). My plan is to keep this liquid in my freezer for fast cooling of beverages, so the liquid needs to be harmless to drink in case some is left on the can. Suggestions? Or maybe the liquid will cool down the beverage too fast making it impossible to get a proper even drinking temperature without freezing the beverage?

• Ethanol, liquid nitrogen or ether jump to mind. – Jan Jun 3 '16 at 21:08
• But they aren't that harmless to drink ;) – Mithoron Jun 3 '16 at 21:26
• @Mith Wait, a Polish person saying ethanol is not harmless? =O – Jan Jun 4 '16 at 12:00

Aim for a brine solution: mixture of water and NaCl. The lowest freezing point for a brine solution is about -20$^\circ$C, obtained with approximately 23 mass % NaCl, as is seen in the phase diagram below (you want to stay within the "brine" part of the diagram). This is not much below the freezing point of a regular freezer, but you may get away with some brine + ice. Or set your freezer to -18$^\circ$C.