PIPING HOT COFFEE

[“Coin operating coffee machine with 4 possible mixtures, each selling for five cents.” Photograph by Wallace Kirkland. February 1947. From the Life Photo Archive. Click for a larger view.]

Why piping hot? “Because of the whistling sound made by very hot liquid or food,” says the Oxford English Dictionary. Its first citation is Chaucer’s “Miller’s Tale” (c. 1390):

He sente hir pyment meeth and spiced ale
And wafres pipyng hoot out of the glede.

In other words:

He sent her honeyed wine, mead, and spiced ale,
And cakes, piping hot out of the fire.

Also some coffee with cream and sugar, piping hot out of the machine.

[The OED gives pipinge and pipeinge as v.rr., variant readings, for pipyng. The ersatz Chaucer is mine.]