The Physics of Winter Backpacking Stoves

Why do standard gas stoves fail when temperatures drop below freezing? It’s not bad luck—it’s physics. Discover how Optimus stoves use smart engineering to withstand the cold.

There’s nothing better than a hot meal after a long day of snowshoeing or mountaineering. Yet many winter campers know the frustration of a gas stove sputtering and going out, even when the canister is still half full. Why does this happen, and how does Optimus technology solve the problem?

The Problem: Evaporative Cooling

Conventional camping gas stoves run on a pressurised mixture of liquid butane, isobutane and propane. When you open the valve, the pressure drops, allowing the liquid fuel to turn into gas, which then burns. However, this phase change—from liquid to gas—requires heat, which is drawn from the fuel and the surrounding air. This is known as evaporative cooling.

As you cook, the canister gets colder and colder. In winter conditions, its temperature can quickly fall below the boiling point of the fuel inside (butane stops vaporising at around −0.5 °C). The fuel remains liquid, the pressure drops to zero, and your stove goes out.

Optimus Solution 1: Liquid Fuel Technology

To bypass the canister problem entirely, experienced mountaineers turn to liquid fuel stoves such as the Optimus Polaris Optifuel. Instead of relying on the ambient temperature to vaporise the fuel, you manually pressurise a fuel bottle using an integrated pump. The liquid fuel, such as white gas or kerosene, flows through a brass generator tube that passes directly over the burner flame. The intense heat of the flame instantly vaporises the liquid fuel inside the tube before it reaches the jet. This physical preheating process guarantees maximum heat output, whether the temperature outside is +20 °C or −20 °C.