Sep 20th, '10, 21:19

Superheated water

by merznd » Sep 20th, '10, 21:19

Hello everyone~

I have a quick question/problem regarding heating water in a glass kettle. I have an old pyrex kettle that I got a while bag and I never noticed this problem until recently when I scrubbed it out very thoroughly with baking soda to remove some scale that was beginning to build up.

After the cleaning the water heats up fine but only boils if it is over halfway full (the glass towards the top of the kettle appears slighly rougher which must allow the bubbles to form).

However, on later infusions when I tend to leave the kettle on the burner on low, the water steams in the kettle but doesn't boil. At first I thought it was just because of the low heat but I had a suspicion that it was still at the boiling point and, sure enough, when I dipped my stainless steel thermometer in the water it boiled up fairly violently all around the steel.

I know it is an odd problem but I was wondering if any users out there have had similar experiences or have any ideas about what I can do to solve it easily.

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Sep 20th, '10, 22:49
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Re: Superheated water

by tingjunkie » Sep 20th, '10, 22:49

Sounds like you might be using reverse osmosis or distilled water? Water actually needs "impurities" to bubble when it boils.

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Sep 21st, '10, 00:47
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Re: Superheated water

by debunix » Sep 21st, '10, 00:47

There are a variety of devices invented to solve just this problem. In the lab, for beakers regularly used for boiling water baths, they get filled with little glass beads to an inch or so. You can buy (or used to be able to buy) glass rings (think doughnut) that you could put on the bottom of the pot--google 'pot watcher'. Still widely available for sale, at least online, and very effective.

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