Camper Trailers Tech Tips

thermal cooker basics




thermal cooker

Thermos Shuttle Chef with two 3 litre pots

Thermal cookers are great for an easy no prep meal after setting up camp on a Friday evening, preparing a meal before a big day of driving or a busy day out camping and exploring with the meal ready to eat when you return to camp.

how do they work

Thermal cookers use the retained heat of the food being cooked to continue cooking by placing the inside pot into the insulated outer pot. It is important to make sure the food is covered in liquid or a sauce so the heat is equally distributed throughout the cooking process. Heat retention is dependent on thermal mass, so the larger volume of food that is in the thermal cooker, the longer the heat is retained. Smaller meals will cool faster, however they can be easily reheated.

Billyboil 3 litre & 4.5 litre sizes Ecopot with 5 litre & 2 litre pots


Thermal cookers need to be filled to around 75% to 80% to work efficiently, so the size of the cooker needs to be considered when making a purchase. Some brands have a single inner pot. If you cook in a larger pot for two people, four meals could be cooked, part of the meal eaten and the rest vacuumed sealed & placed in the fridge or frozen for a quick meal later during the trip. Other brands may have two internal pots of various sizes in the one outside pot, suitable to cook a main meal and perhaps a dessert. 

The cost of thermal cookers start from under $100 up to nearly $500. Brands include Thermos, Primus, Billy Boil, Eco Pot, Dream Pot, Thermo Pot & Aldi Thermal Cooker to name a few.

buying tips

* The size of the meal you normally cook will depend on the thermal cooker pot size.
* The inside pot is best mostly filled to maintain the heat.
* Make sure the pot lids can be locked if you are going to use the cooker when driving.
* What is your budget.

There are two types of insulation methods
- the foam insulator loses about 6 degrees per hour.
- the vacuum insulator loses 3 to 4 degrees of heat per hour.

There are also thermal pots that will fit two pots inside the one insulation pot. Great for cooking a dessert as well. 
Any recipe designed for extended simmering, slow cooking or one pot cooking is ideal for a thermal cooker. You probably already have a stack of suitable recipes. Most brand thermal cookers have a collection of recipes either in a booklet or on their website.

Billyboil 3 litre & 4.5 litre sizes Ecopot with 5 litre & 2 litre pots


The stainless steel inner pot is used on the stove as you would normally to bring your food to the boil or partially cook as required. Once the food is heated through, switch off your stove and place the inner pot inside the insulated outer pot and close the lid. The thermal cooker will continue to cook the food using the retained thermal heat in the already heated food.

Remove the inner pot when the cooking time has elapsed or up to 12 hours later, when you are ready to eat.

cooking tips

* If using pasta or rice, extra water may need to be added as both absorb moisture and the result might be very dry food. Both pasta or rice are often added to slow cooker meals to add bulk to the cook.

* Once the cooking pot is added to the thermal, leave the lid closed until the food is cooked Ė donít be tempted to keep checking it - removing the lid to check the food will let out heat and the food/thermal will go cold quickly.

* The inner pot can be re-heated on arrival at camp if needed.


info by Rob
january 2024