Wait but tell me more, what kind of math does our godforsaken measuring system make sense for? I'm horribly curious!
oh dear oh boy okay, Iâve tried to explain this to people and had them just get more annoyed, so Iâll give it a shot, but no promises that it will make any sense. Disclaimer also that I donât really know what Iâm talking about, Iâve just done a lot of baking, and ages ago I read something by Plato explaining why the musical scale is how it is, and Iâm extrapolating from the two
(wow this turned out way longer than I meant it to because ITâS MIDNIGHT)
the metric system is a base 10 system, like most modern human math, so it is easy to use in the way people tend to do math these days - ie, by sitting down with either a piece of paper or a calculator and doing sums. Itâs a good system for a lot of things, especially scientific applications where you need to be VERY precise and donât want to waste time converting units, and need to do shit like calculus. Itâs a highly rational way of doing itâŠif you are literate.
if you arenât literate, or are less literate, itâs not a sensible way to construct a measuring system at all. If you measure something and come up with 367.45 cm, thatâs nothing. Youâre going to forget it, and you canât easily divide it by anything, thereâs no way to go from here
But consider the English Foot. Weâve all been working with a base 12 system without realizing it, and without really utilizing it for what itâs best for, which is easy mental division. This is where people get mad at me, they say math all gets terrible and ugly when you do it in feet, you end up trying to figure out how many sixteenths of an inch 0.135 is, or you end up with repeating decimals, and it all sucks super bad. To this I say yes, it does, because youâre thinking like a modern algebra student, and not like a medieval bricklayer.
The base 12 system of the traditional English foot is fantastic for mental math, because 12 is a highly divisible number. Itâs easily divisible into halves, thirds, quarters, and sixths by most people in their heads. The inch is then typically divided into 1/16ths, which *super* suck to deal with on a calculator, but are really quite friendly if you just keep them as fractions like God and the Magna Carta intended. This is the kind of math most artisans need to do. You want supports placed evenly along a wall, to divide a piece of fabric in half, or to double a recipe. Nobody 1.7xâs a recipe. Metric would be great for that, but why would you do that? It wouldnât be worth the math involved.
And listen, I also use a lot of metric baking recipes. Everything is in grams, you can measure everything the same way, and itâs super accurate. Theyâre great if you have a digital scale, but before the age of digital scales? Unfathomable. You (a medieval peasant) have a cup youâve decided is The Cup, and sometimes you put in a half or a third or a quarter of that cup. THAT makes sense. Also, itâs a lot easier to double something that calls for 1 cup of flour than it is when it calls for 136 grams of flour, and this is for me, a person who learned math in the typical modern way and always has a calculator in their pocket. I would have the sourdough recipe I make every week memorized if it wasnât in fucking grams. I DO have my pie crust recipe memorized. For every cup of flour you put in a third of a cup shortening, one tablespoon of butter, and start with 3 tablespoons of water (and a dash of salt). A double crust pie takes about 3 cups of flour, so thatâs one cup shortening. Easy! A third of a cup of shortening in grams is 68.3333333. Thatâs nothing! Thatâs garbage!
âWouldnât it be more accurate to measure 68.3333333 grams, though?â Sure, but the amount of wet indigence you need to put in any baked thing changes with the fucking weather! Thatâs why this recipe says âstart with 3 tbs water.â Thereâs no need to be more accurate, and in fact it would make things more difficult.
Okay that turned into a tangent about how to make pie crust, a thing I think everyone should learn because pie crust is delicious, but i hope you get the idea. TLDR sometimes you just want to divide things in thirds and have it not suck ass. The eldritch sigil of measurement conversions is a little less threatening if you realize every step up or down is a factor of thirds or fourths
fuck oh no another half remembered piece of pop science coming at you - the largest number a typical human can hold in their head *without language* is 3. You donât need numbers to count to three, you donât need to count to be aware of three, you can just see three things and say âthatâs three.â Donât believe me? Thatâs the whole basis of Roman numerals. The numbers 1-3 are representational, after that they get more symbolic, and you never end up with more than three of the same symbol in a row. After III comes IV, not IIII, and itâs just that III is much easier on the brain. For the same reason, a lot of English conversions are in factors of 4. There are 4 cups in a quart, and 4 quarts in a gallon, so youâre only dealing with measurements that are easy to hold in your head without counting. You never have to count out 4 cups if you convert. You either need 3 cups or 1 quart. Does that make sense? Anyone who has done Big Cooking should know that if you have to count cups beyond 3 or 4 it becomes very easy to lose track.
Now iâm not saying itâs all logical. It would be great if every step was a factor of 4, but they had to get fancy and throw pints in there. Pints arenât too bad, thatâs a factor of two, but Iâll be the first to admit that it makes no sense for one tablespoon to equal three teaspoons instead of four. But because this is a system that evolved over time instead of being constructed intentionally, you have to cut it some slack. Iâm sorry to anyone who decided to read this, I should be in bed, but I actually care a lot about this and I swear itâs not just stockholm syndrome from Being American
This is the best explanation of this system that Iâve ever seen and Iâm so grateful to have found it, because now I can shove it into the face of every person who whines at me about preferring Imperial measurements for cooking.
Pound cake, traditional recipe:
1 pound flour. 1 pound butter. 1 pound sugar. 1 pound eggs. (Roughly 8-9 eggs.)
Nobody is going to make 450g cake.
Also:
Teaspoons used to be 1 fluid dram, which is ÂŒ of a tablespoon, or 1/8 of an ounce. This was a widely used apothecaryâs measurement - there are even smaller ones for medicinal purposes. (Scruples & grains are smaller than drams.)
In the 17th century, tea was EXPENSIVE in England, so tea spoons and tea cups were SMOL. However, in the late 18th century, the tax on tea dropped from 119% to 12.5%⊠so more people could afford tea, and tea-drinking accessories - the cups and spoons - got bigger. Eventually teaspoons stabilized at 1/3 of a tablespoon.
This is the only response to this bizarrely successful post that I care about
The responses to this are absolutely sending me because theyâre all like âno, youâre wrong, metric is fine if you round and can do basic math!â And, like, yeah, thatâs true. But this post is specifically talking about measurements developed by and for illiterate people who never learned basic math. Do you know why a yard is the length it is? Because it was the distance from a manâs nose to the thumb of his outstretched arm. An inch was the width of a manâs thumb, a foot was the length of his foot. Traditional imperial measures are based on the human body, designed for people who need rough uniformity and to gauge measurements without tools. The longer lengths are more complicated â a mile derives from the length of a Roman mile, which was 1,000 paces or 5,000 Roman feet and so was closely related to distance covered by marching legions (this one is a bit of an exception, as a state-defined measurement rather than one that comes from folk use, but thatâs why itâs so weird.) An acre was the amount of land a team of oxen could plough in a day with a wooden plow. These are practical units for people who were mostly illiterate and innumerate and needed approximations they could eyeball or that related to how they actually used the land.
Weight is weird. The base unit is actually the grain, which is the weight of a grain of barley. But pounds come from the Roman libra (scale) weight and their system of measures goes back to ancient Mesopotamia and we donât actually know what it was based on. Something that made sense then, presumably. But systems of weights were really not used outside of commerce and were measured by standardized systems of weights on a scale, so the merchants bought a set of standardized weights and used those.
The extra fun part, though, is when people started trying to standardize all these measurements. So, yes a pound was based on an ancient weight system but different merchant groups had different approximations of that that they standardized. So dry goods were sold with the wool pound and liquids were sold with the London pound and thatâs how a fluid ounce and a mass ounce ended up different. And a wine gallon was 8 London pounds, divided into 4 quarts and 8 pints (this is why a pint of liquid weighs roughly a pound.) And then our volumetric measures for baking come because the artisans making drinking vessels roughly standardized the size of those for uniform sale of beverages at taverns and so on and *then* people who reached for the most convenient scoop at home grabbed their roughly half-pint cups.
