It can be a challenge to keep your beverages cold while camping. A cold beer tastes better than a warm beer. After extensive research I have come up with a system which will keep your beer cold while on a overnight kayak/camping trip i.e. having cold beers over 2 days, one night. Here's some general tips:

Start off with cold beer.
Use block ice instead of crushed ice.
Have no spare space in your Eskey or cooling box.
Keep the Eskey in the shade
Don't open it often
Have realistic expectations

I call the system 'Ice Rolling' because you roll a beverage can on a block of ice to cool it. The melted ice can be poured into a drink bottle and also drank. Useful when camping and weight and space is at a premium.

Step 1: Getting Ready

Fill several 750 mill tray containers with water, place lids on and freeze overnight. Cool the beer in a fridge and if you can get them really cool by placing them in the freezer for an hour before you leave. But don't freeze them as this can cause the cans to burst.
Place the cans and ice blocks in a cooler, the ones I use are reflective foil with insulation doubled up, one inside the other. While not the best at keeping things cold, I use them because they don't take up much space. I then place them into a flexible esky.

Step 2: Beverage Can Rolling Apparatus

To roll the can, an apparatus was designed and manufactured. This involved 'repurposing' a sucker which was being used on a soap tray and glueing it to a piece of dowel using a hot glue gun. This allows the stick to be stuck onto the end of a beverage can and rotated with your fingers.

A valve lapping tool can probably be used to rotate cans as well.

Step 3: Keep Closed and in the Shade

At your camp site keep the ice and beer in the shade until you want to use them.
As cool sinks, it might be an idea to place an insulated mat under the Eskey if you have one.

Step 4: Ice Rolling a Can

To use this beer cooling system:

- Take the container with ice in it out of the esky, the ice will probably have melted a bit, but thats OK.
- Place a beverage can on the ice or into the icy water.
- Rotate the can using the beer turning apparatus, I cooled a beer can to 4c after about 5 minutes of rotating on ice.

Step 5: Enjoy

Pour the beer into a drinking vessel,
Drinking Vessel

then place into a stubby holder (greatest invention to have come out of Australia) and enjoy being in the great outdoors.

Now that you know how to cool beer outdoors, check out how to cool beer Fast indoors:

Cold Beer in 6 minutes

Cold Beer in 3 minutes

Step 6: Epilogue

On a kayaking trip, A 1 Liter milk carton had been filled with water and frozen. To bring it to the camping site it was placed in a small box made from polystyrene foam to keep it cold. After 30 hrs there was still a frozen center. The top was cut off with a knife and a beer placed into the cold water. It was turned a couple of times over a 20 minute period to cool it.

Results: While the beer was cooler it was really wasn't cold enough. The beer really needed to be spun with the 'sucker' made earlier to cool it better. Unfortunately the 'sucker' hadn't been packed. While the polystyrene box did keep the ice cold it was a little bulky and when no longer required still took up space. There is also benefit if having the beer very cold before taking it and then giving it a cold 'boost' at the campsite compared to trying to cool it from room temperature. Next time I will cool the beer before leaving home, use a soft cooler for the milk carton ice block, bring a 'sucker' to spin the beer with and use the ice as a cold 'booster'.

Step 7: Epilogue II

On another camping trip 4 cold beers were packed into a small soft Eskey along with a 2 litre carton of frozen water (empty milk carton being the container). Cool beers were enjoyed the first afternoon and also on the 2nd day (32 hrs cooling). There was also the benefit of drinking cool water from the carton.
Placing the beer and frozen water carton in a 'dry bag' inside the Eskey seemed to help in keeping it cold.