The integrated microwave in the coffee kitchen at my old workplace has a sticker showing a glass with a spoon. The manual suggests heating water only with a spoon in it to make sure bubbles can form at boiling temperature.
2023-02-08 23:22:13 +0000 UTC
I regularly heat my morning coffee, 1 1/2 cups, black, no sugar, in a 2-cup Pyrex measuring cup, 3 minutes on high, and have noticed that on rare occasions, if I put my spoon in immediately after removing it from the microwave, the coffee will boil over. Now I have a name for it.