Piping Hot!

This afternoon, as I sat at lunch with Katie, her mother, and her grandmother, the expression "piping hot" was used to describe a steaming plate of cheese ravioli. However, even as it was said, we were all simultaneously struck by the fact that (a) we knew precisely what the phrase meant, but (b) we had no clue why it meant that. English is full of such enigmatic idioms: the fossilized remnants of once-living metaphors, long forgotten save for their linguistic bones. When I encounter one of these, I usually shrug and pass on my way; but today, I decided to track down the truth.

First, however, I was alarmed by another impulse: namely, the desire to make up an explanation, simply to seem the smartest person in the room. This is a character flaw I sometimes see in myself, but suspect (uncomfortably) that it is present far more than I notice. At any rate, I instantly concocted my own invented etymology of "piping hot", but decided not to present it, knowing it was false. I am ashamed of the plausible pretention to which I am prone. (Note the alliteration: pretentious!)

Anyway, I did some research and found this: The Word Detective, Dec. 20, 2002.

The question, of course, is what all this has to do with pipes, and the first thing to note is that the "pipes" in "piping hot" are not your normal plumbing "pipes." To "pipe" in this sense is to make a sound like musical pipes (think bagpipes), i.e., to emit a whistling or hissing sound. Food served "piping hot" is, thus, hot enough to hiss, sizzle or bubble.

So, there you have it: piping hot food is food so hot you can hear it. Simple and far more reasonable than my own explanation, which involved Romans and the invention of central heating.