The unending struggle against thermal equilibrium, or, trying to get my coffee just right

© 2014 Gene Breshears
Coffee always helps.
I have a favorite coffee mug. It’s purple and holds a large amount of coffee. It’s a nice, solid mug that isn’t top heavy (a feature that a previous favorite mug did not share, which resulted in a lot of spilled coffee and swearing). You know those markings on the side of most automatic drip coffee carafes that tell you how many cups are in the pot? If my favorite mug is completely empty and I fill it from such a pot, the numbers on the side indicate that I’ve poured out a bit more than four cups from the pot. A standard-ish modern coffee mug usually holds about two cups. So when I said this one is large I meant it.

I like the mug a lot.

There really is only one problem, which I have been dealing with for several years, ever since we bought our current microwave.

This mug (my favorite) and this microwave do not quite get along... © 2019 Gene Breshears
This mug (my favorite) and this microwave do not quite get along…
For various reasons, most mornings when I go to get myself my first cup of coffee at home, there is usually enough cold coffee leftover from the previous day to fill my favorite mug. So I fill the mug and stick it in the microwave and immediately face a dilemma. If I press the 1 minute button on the microwave, by the time it is done, the coffee in the mug will be only barely warmer than tepid. If I select, say, 1 minute and 30 seconds, when I reach for the mug I will find that handle is scalding hot, while the body of the mug is only slightly warm, and the coffee is also only slightly warm. If I select a full two minutes, the coffee itself will be a very nice temperature, but not only with the handle of the mug be too hot to hold, but the body of the mug will also be a warmer than is pleasant to hold.

Exactly why the mug itself heats up more than the coffee in this microwave doesn’t really matter. The thing is, according to the Laws of Thermodynamics, once the mug has reached a point where it is warmer than the coffee, one should need only to wait for a bit, and the mug will cool down while the coffee absorbs some of that heat the mug is losing and warm up. So you would think that the ideal option would be to select the one and a half minute cycle, carefully carry the mug grasping the body and not the too-hot-to-touch handle over to my desk or whatever, and in let’s say five minutes time everything would be perfect.

But it doesn’t work. Most of the mug handle’s heat, instead of going into the rest of the mug and eventually the coffee, seems to mostly go into the air around it. The upshot is that by the time the mug’s handle is cool enough to comfortably grip it, the coffee has cooled down closer to room temperature than the warmth it had before.

Once a fresh pot is made, I have an easier time managing the temperature. Usually the coffee is cold by the time I’ve drank half the mug, so I can top it off from the bot and it reaches a nice warm—not too hot, not tepid. And if can do a little 30 second zap if the coffee is a bit cooler than I like. So long as I don’t let it get back down to room temperature, anyway.

I’m sure there’s some sort of life lesson I should be able to derive from this. It’s like the tiniest annoyance in my life. It’s been on my mind more lately because between one or the other of us being sick and all the weird weather, I’m been working from home a lot more often. And this will surprise some people since I seem to by such a coffee addict, but I almost never make coffee at home on days I go into the office. My first caffeine of the day on those days happens is the free stuff they have in the kitchenette down the hall from my desk.

Ah, well, I’ll just have to soldier on!

4 thoughts on “The unending struggle against thermal equilibrium, or, trying to get my coffee just right

  1. Have you considered using something like a 4-cup pyrex measuring cup to heat up the coffee, then pouring the coffee into your favorite mug? If the cup ends up cooling the coffee too fast you could either pre-warm the cup with some warm water or heat the coffee up a little bit more before pouring.

    1. I have considered it, and usually talked myself out of it because of the ghostly voice of my grandma asking why I’m dirtying up an extra thing. Which, as soon as I type it, I know is silly, given that I’m irritated by the temperature and in this case “dirtying up” means I just have to rinse the pyrex measuring cup or whatever and let it dry. 😛

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