Today is Pi Day, so named because the date is rendered in the United States as 3/14, which are the first three digits of the ratio between a circle’s circumference and its diameter. (In the rest of the civilized world, I suppose Pi Day would make more sense on April 31, if such a day existed on the Gregorian calendar.*)
It is traditional to consume pie on Pi Day, for the obvious reasons that “pi” and “pie” are homophones, and that most pies are circular. On paper, these are compelling reasons. In practice, they fail to outweigh the fact that mid-March is a terrible time to eat pie.
Let’s break pies into approximately pi groups—i.e., three. The first group is summer fruit pies. These won't work on Pi Day: Stone fruits and berries are totally out of season in March. The second group of pies comprises most custard and cream pies, which are always very rich with butterfat and egg yolks. If you are like me, you are totally sick of rich desserts by the time March rolls around, and you’re ready, after months of wintertime overindulgence (Christmas cookies, Valentine’s Day chocolate, etc.), to take a little break from heavy desserts. The third group of pies is those served in late autumn: apple, pumpkin, pecan. These point toward the strongest argument against eating pie on Pi Day, which is that we already have a Pie Day, and it’s called Thanksgiving.
What to do about Pi Day’s inopportune timing vis-à-vis pie consumption? Last year I had the fever-dream-like vision that Mole Day and Pi Day should switch places: We should eat mole sauce on March 14 and apple pie on October 23. But of course, this solution is impossible: Pi and mole are mathematical and chemical constants, respectively. We cannot alter them to suit our culinary whims unless we are prepared to rip a hole into the fabric of spacetime and travel to an alternate universe.
A more workable solution is to broaden our definition of acceptable Pi Day fare to include all foods that begin with “pi-.” Sip a Pimm’s cup with a piquillo pepper garnish. Make a pissaladière with pine nuts sprinkled on it. If you want to represent the mathematical importance of pi with your Pi Day meal, have a perfectly round pita, or, better yet, some pierogi. Pierogi are usually shaped like half circles, so one of their edges is a diameter, the denominator of the fraction we celebrate on Pi Day. Put two pierogi together to show what a circumference is, take them apart again to show what a diameter is—no cutting required. It’s an elegantly rational solution to an elegantly irrational problem.
*Update, March 14, 2014: An earlier version of this blog post failed to clarify that April 31 is not a real date.