Why a Bakers Dozen is 13 Instead of 12
There are three main theories for why a baker’s dozen is 13 instead of 12, but most think
it has its origins in the fact that many societies throughout history have had extremely strict
laws concerning baker’s wares, due to the fact that it is fairly easy for bakers to
cheat patrons and sell them less than what they think they are getting.
These societies took this very seriously as bread was a primary food source for many people.
For example, in ancient Egypt, should a baker be found to cheat someone, they would have
their ear nailed to the door of their bakery.
In Babylon, if a baker was found to have sold a “light loaf” to someone, the baker would
have his hand chopped off.
Another example was in Britain in the mid-13th century with the establishment of the Assize
of Bread and Ale statute, which was in effect all the way up to the 19th century before
being repealed by the Statute Law Revision Act of 1863.
The Assize of Bread and Ale statute set the price of ale and what weight a farthing loaf
of bread should be.
Specifically it stated: “By the consent of the whole realm of England,
the measure of the king was made; that is to say: that an English penny, called a sterling
round, and without any clipping, shall weigh thirty-two wheat corns in the midst of the
ear, and twenty-pence do make an ounce, and twelve ounces one pound, and eight pounds
do make a gallon of wine, and eight gallons of wine do make a London bushel, which is
the eighth part of a quarter.”
So basically, in terms of bread, setting the relationship between the price of wheat and
what the subsequent price of a loaf of bread from a certain quantity of wheat should be.
Even though this statute was enacted at the request of bakers, it still posed a problem
for them.
If they happened to accidentally cheat a customer by giving them less than what they were supposed
to as outlined by the statute, they were subject to extremely severe fines and punishment,
which varied depending on where the lawbreaker lived, but could include, like the Babylonians’
punishment, losing a hand.
As it wasn’t that hard to accidentally cheat a customer, given making a loaf of bread with
exacting attributes is nearly impossible by hand without modern day tools, bakers began
giving more than what the statute outlined to make sure they went over and never under.
Specifically, in terms of the “baker’s dozen”, if a vendor or other customer were
to order a dozen or several dozen loaves of bread from a baker, the baker would give them
13 for every dozen they ordered.
Likewise, when selling quantities of anything, they’d give 13 measures when only 12 were
purchased.
This practice eventually made its way into the Worshipful Company of Bakers guild code
in London.
This guild was actually started in the 12th century and had a large part in formulating
the rules on the Assize of Bread and Ale statute.
All that said, although the above is generally thought to be the correct origins for a baker’s
dozen, there are two alternate theories put forth that are somewhat plausible, though
lacking in hard historical evidence and visible progression.
The first is that bakers would sell 13 loaves to vendors, while only charging them for 12
which allowed the vendor to then sell the 13 at full price earning a 7.7% profit per
loaf.
So in this case, vendors were being given a sort of wholesale price, but without breaking
the laws outlined in the Assize of Bread and Ale which had no exceptions for allowing a
cheaper price to vendors.
This theory has some holes in it, but is somewhat plausible on the whole.
Yet another theory is that it was simply a product of the way bakers bake bread.
Baking trays tend to have a 3:2 aspect ratio.
The most efficient two-dimensional arrangement then of loaves/biscuits/etc. on such a tray
results in 13 items with a 4+5+4 hexagonal arrangement, which avoids corners.
It was important to avoid the corners because the corners of a baking tray will heat up
and cool off faster than the edges and the interior, which would result in not cooking
anything on the corner evenly with the rest.
This theory doesn’t explain why they’d sell them in batches 13 for the price of 12,
but at least explains why they may have commonly made them in batches of 13 in the first place
and is still a possible source, or at least contributor, to the “baker’s dozen”
if it was fairly universal that baker’s baked things in groups of 13, as is suggested
by the theory.
But, in the end, most historians think that the first theory- that bakers simply were
trying to make sure they didn’t accidentally break any laws- is the correct one.
Bonus Facts: • The term “baker” dates back to around
the year 1000.
Another term that meant the same thing from that time was “bakester”.
This latter word is thought to have referred to female bakers; this is similar to how a
“webster” was a female weaver, with the “-ster” ending implying a woman.
From this, if your last name is “Baxter”, you probably had a professional female baker
somewhere up your family tree.
“Bakester” is where the surname “Baxter” comes from.
• One might think checking to see if a baker was cheating you on a loaf would be as simple
as weighing the loaf, but this was not actually the case.
Bakers had many tricks up their sleeves for cheating customers while having the weight
come out more or less correctly.
One such trick was to add a bit of ground sand to the loaf to get the weight just so,
while being able to use less wheat.