Hi there,

We all know that heating and cooking with gas (natural gas = methane) is more ecologically friendly than electricity, etc. That’s not as true for LPG, but LPG or propane or butane is still better than electricity. Especially if there’s no pipeline available!

I was just thinking about making Sunday dinner, and the thought of how much energy goes lost when you’re cooking just popped into my mind! And since our kitchen has an LPG-fired range, “cooking with gas” is a natural outgrowth, or something like that!

A Moderate Flame

What I was thinking about is the problem I have when I’m cooking small quantities of food on the range part. We have a semi-professional cooking unit; it’s 1 meter (3ft-3in) across the top, and has five burners on top, one of which is a large double burner in the center for cooking water for pasta. The single oven is 76cm (30 inches) wide with a strong-hinged door for stability. It’s great for cooking large amounts of things, and of course, with gas, when it’s on it on and when it’s off, it’s off. No residual heat as with electrical “burners”.

But what I was thinking about is what happens with a pot on a burner that is barely large enough to cover the support grid. What happens when you turn the gas on all the way, is that much of the heat goes up the sides of the pot, and gets lost in the process.

I made a totally un-scientific study, and discovered that the time it takes to get pot of water to a full boil (not just boiling off the sides) when I’m cooking with gas is virtually the same, whether I have the gas turned on full or if I only have it on about halfway – enough that the visible flame does not get shielded away from the pot and guided up the side with almost no heating effect. Lesson learned?

efficient 50% gas flame	inefficient 100% gas flame

Heat transfer when you’re cooking with gas requires good contact to work properly. It’s like using a hammer – if you just wave the hammer around, it doesn’t do much, but if you hit the nail on the head with it, it’s a great tool!

A Watched Pot

There’s another tip that you should remember, also. Even if you’re cooking with electricity, it still applies! When you’re heating water for pasta or potatoes or something else, remember to keep the pot covered. If you don’t, you will lose a lot of energy right out the top of the pot! It will leave as water vapour (steam) and also as radiated (like heat rays) and convective (like heat waves) heat loss. If you don’t believe me, think about a kitchen in a cold winter – if you’re boiling water on the stove in an uncovered pot, the windows will “steam up” as water vapour condenses on the cold surfaces. If the pot is covered, that doesn’t happen!

You’ve heard the saying, “a watched pot never boils” – now you know why: it takes longer because so much heat leaves an uncovered pot!

Thanks for reading what we write!

Jimmy Craig

That’s Cooking With Gas!