2. Cool beer in ice saltwater
Take a large tray or bowl. A sink will also do the trick, but a nice glass dish looks fantastic. Just make sure the beer has enough space. Fill the dish with water and add plenty of ice cubes. Add a few tablespoons of salt - lots of salt isn’t anything to worry about. Stir and place your beer in the dish. After about a minute give it another stir and a minute later your beer will be cold - after just 2 minutes!
How does it work? Saltwater freezes at a much lower temperature than freshwater. By adding salt to ice water, a chemical imbalance is created, whereby a self-cooling (cryogen) mixture is produced. To rectify this imbalance, the temperature plummets to below freezing (the eutectic point) to extract energy from a heat source - in this case, your lukewarm beer. Impressive stuff, right?