This is a trick question, obviously, as everyone knows there are actually 13 loaves of bread in a baker’s dozen. So, how did this strange idiom come about? And no, the answer is not that bakers are just terrible at maths. This one, as the Australian Writers’ Centre explains in one of Dean Koorey’s excellent Q&As, actually goes back many centuries.
It was first recorded in writing during the early 1600s, but the tradition of giving out 13 loaves of bread instead of 12 goes back a few more hundred years. If you really dough (terrible pun intended) need to know why, you should know there are actually two main theories about it.
The first involves avoiding persecution. Due to the price of wheat during the Middle Ages, bread was a heavily regulated thing – literally. The authorities didn’t look kindly on bakers who sold bread with a high air content. One wonders what they’d make of the modern-day problem of chip packets full of air. Given the way bad musicians were punished in the Middle Ages, it’s safe to say it would probably involve flying fruit.
Anyway, bakers came under scrutiny by having every dozen loaves weighed. Worried that natural variances would send them to jail, bakers safeguarded their samples by throwing in an extra loaf to ensure they were over the required weight. The extra loaves they added in were known as “in breads” (nothing to do with certain distant cousins my family doesn’t talk about).
A Tiny Profit Margin
Theory number two – and considered more likely – relates to profits. That extra 13th loaf was the only profit retailers would make. Because of the high regulation involving bread, profit margins were tiny. The retailer would pay the baker for 12, be given 13 – a “baker’s dozen” – and that extra loaf was the profit they made.
In case you’re wondering, the “13 for 12” thing was in fact just for the bakers. And it’s a quirk that has lasted at least in idiomatic form until today, even if the tradition of throwing in an extra loaf or roll is not universal in the age where you can buy a loaf of gluten-free, leavened, miche-inspired, soy-infused, yeast-identifying, macadamia-crusted soda sourdough brioche for a dozen bucks. Or is that $13?