Don’t worry—kaolin, or porcelain clay, has not turned out to be a source of cancer in California mice. My modest experiment tested for an entirely other devastating consequence: cold coffee.
The scalding question behind my not awfully controlled but purposeful test was to determine which of my two 12-ounce mugs was going to be my favorite—my glass one that’s Walking Tall (it holds 12 ounces with room, so I can walk from counter to table without spilling any precious contents), or my stylish porcelain one that is Tall in volume but not in stature (it clocks in at 12 ounces to the brim and I sip at the counter to conserve what would otherwise inevitably spill). Why was this important? Because the winner would accompany me on visits to Starbucks, unless pre-empted by my Grande travel tumbler or my favorite (and only) Grande mug. So big things were at stake.
I normally get a Tall coffee, because that is the size exchanged for an empty Starbucks coffee bag, the 12-ounce size sold in grocery stores, and having the special offer printed on them. I’m not going to save a dime on a free drink; I simply dislike drinking from paper cups.
I decided to compare the heat loss of my two Tall mugs, using, of all things, a meat thermometer and a timer. The mugs took turns being filled with 12 ounces of boiling water, and I noted for each the water temperatures at 5, 10, and 15 minutes. This method was necessary because I only have one meat thermometer and I didn’t want to spend very much time with this, as important as it was.
The results were virtually identical. My porcelain and my glass mug both read 170° at 5 minutes, 158° and 157° at 10 minutes, and 145° at 15 minutes. I was surprised; perhaps I have discovered a new constant or something.
Since the Walking Tall is easier to carry to the table, it will be my take-to-Starbucks mug. Or I could take one of my 16-ounce mugs, because the clever barista can pour a Tall coffee into a Grande mug. I recall this being impossible at a Tacoma Starbucks some years back, but a tide of resourcefulness seems to have swept Starbucks’ shores.
Admittedly this isn’t an experimental protocol that would readily dislodge funding from the NSF, but at least I know that liquid cools no faster in a glass mug than it does in a porcelain mug. Resolving this overwhelming question freed me to select a favorite mug according to more subjective criteria, and I think such things are consistent with what Favorite things are.