Have you ever noticed how, if you stir your latte*, when you pull out the spoon it’s piping hot, yet there is no steam rising from the latte itself? That’s because the milk foam on top is such a good thermal insulator thanks to all the tiny air bubbles trapped in it. Cool, isn’t it?
*I never noticed before today, when my friend Sara pointed it out, because I have NEVER before put a spoon in my latte. Because I am always observing double-diffusive mixing in my latte and would never do anything that might destroy the stratification. But this once it might have been worth it. The things we do for science… :-D
Yes! You should add marshmallows to prevent heat transfer both by evaporation and conduction.
Elsa, I’m pretty sure it was you I had that hot chocolate with back in 2011. Recognize your hands?
Actually, no matter what temperature you like your chocolate best at – you should always add marshmallows! :-)
For those of you who want to read more about marshmallows and ocean mixing, check out a very nice post here. For those others getting worried that I’ll only talk about tea until the end of time – nope! Tea week is now officially over and we’ll be back with “real oceanography content” pretty soon!