Striking a Blow for Science with the Coffee Temperature Experiment!

We got our new thermometer the other day and did a coffee cup temperature test. It’s certified by the National Sanitation Foundation (NSF), but we’re not sure where it was manufactured. The instruction sheet looks like it was translated into English.

First, we measured the temperature of coffee in different cups. We measured the temperature of coffee in a double wall glass mug and compared it with the temperature of coffee in a stoneware mug. Stoneware is a type of ceramic.

Right after brewing, the coffee in the double wall glass mug was around 180 degrees. In the stoneware mug, the coffee temperature was around 160 degrees. After 5 minutes the temperature dropped by about 20 degrees in both mugs. Not a big surprise to learn that the double wall glass mug kept coffee hotter.

In fact, I previously noticed when I drank coffee from the stoneware mug last week, it was less hot right after brewing.

Sena wanted to test the Keurig machine to see if the preference setting for making coffee hotter actually worked. In fact, there was no difference in the coffee temperature in either the glass or the stoneware mug after setting the temperature higher.

We then tested the claim of the makers of our old Black & Decker coffee maker that preheating the carafe with hot water actually kept coffee hotter. We were a little surprised that it seemed to work for the stoneware mug, but not for the double wall glass mug.

Just in the interest of full disclosure, we used plain water for the last two experiments. We didn’t think getting buzzed out on coffee was a worthwhile sacrifice in the name of science.

So, the takeaways from this experiment:

1. The preference setting for temperature adjustment on the Keurig may not be all it’s cracked up to be.
2. The stoneware mug didn’t keep coffee as hot as the double wall glass mug in either the Keurig or the Black & Decker model.
3. The stoneware mug seemed to stay hotter when we pre-warmed the carafe on the Black & Decker coffee maker by filling it with hot water before brewing. Be sure you empty out the hot water first.

If you don’t mind sacrificing hot temperature for looks, then go with stoneware mugs. I guess some male reviewers said things like, “Now there’s a man’s coffee mug! I guess maybe that’s because they’re broader than they are tall—I mean the mugs, not the men (although I don’t know if they sent photos of themselves).

By the way, extraterrestrials are not intimidated by a thermometer.