CAMPING THE KIWI WAY
UNITING NZ CAMPERS
Camping without a fridge: chilly bins and cooler bags
I am no expert, but here are my tricks for keeping food and drink cool or fresh when camping.
In the old days, people used “meat safes” or “safes” which were insect-screened, ventilated boxes or containers located in cool, draughty places. I have no experience with these aand can’t comment about them. My experience is with chilly bins or Esky cooler bags.
Without a fridge it is hard to cool things down, so when using a chilly bin or Esky it is important to get everything as cold as possible before you add them in. For instance, we would pre-freeze our drinks in plastic bottles and our meat etc. and these would slowly thaw during our trip. We also pre-froze 3 litre juice bottles filled with drinkable water for a few days before we left so they were really frozen solid. They provided a good reservoir of coldness and when they melted we drank the cold water. When restocking your chilly bin try to get pre-cooled or frozen food to go in it.
The coldness in your chilly bin can be extended by:
Keeping it in a cool shady spot (this may require shifting it around your camp as the sun moves around).
Having it full of cold stuff so there is less room for warm air to circulate around inside it.
Avoid opening and closing the bin any more than you need to.
Don’t leave things like milk out of the chilly bin longer than necessary as they will warm up.
As said previously, without a fridge it is really hard to cool things down, but there are a few tricks.
First some science.
When something changes from solid to liquid (like ice to water) or from liquid to gas (like water to water vapour) it sucks in heat from the stuff round it. This is effectively how refrigeration and heat pumps work. You can also sometimes see this as condensation or cold patches on the outside of a gas bottle as when the gas inside is drawn off it converts from liquid to gas.
Trick 1: Party ice
Use a bag of party ice, a chilly bin and salt to cool your drinks or to chill some freshly caught fish to take home.
Empty the ice into the bin with your drinks or fish and add some salt and maybe a little bit of water (or use sea water). The salt makes the ice melt faster.
The ice needs energy /heat to melt, which it sucks out of your fish or drinks. This cooling is more rapid than just packing stuff in ice.
Trick 2: A damp cloth
A damp cloth wrapped around what you want to cool will provide cooling as the water evaporates off the cloth.
For water to evaporate it needs to go from a liquid to a gas which requires heat which it sucks out of the surrounding objects. This is increased with more air flow. Think about how cold you get wearing wet clothes on a windy day even when the day is warm. This is basically how cooling towers work.
Another variation I saw in Egypt was roadside drink stations that looked a bit like large shady rural letter boxes (roof but no sides) with unglazed earthenware jars full of cold water. They were not glazed and were semi-porous so the outsides were always damp and evaporation was happening to keep the water cooler.
A couple of other things to be aware of
For some foods like milk and butter the light is as much a problem as the temperature and so keeping them in a dark place is important.
Cooling drinks in a stream will only work if the stream is colder than the air which often it is not. Our skin is normally about 33°C so most often the air and stream water are going to be cooler than us and we will be shedding heat to them. As water is a better conductor of heat it will feel colder than the air even when this may not be the case. So sometimes putting your drinks in the creek ws0ill actually warm them up if they are already at air temperature.
Evaporation can lower the temperature as much as 15°C