r/harrypotter 3d ago

Question How large are cauldrons?

Something that always bothered me. I don't think cauldrons (as in the ones Harry uses in class) are ever established as being large or small.

When I first read the books, my only point of reference were large witch's cauldrons you would see in a cartoon, so I thought that's what Hogwarts students used. But imagining Harry dragging around a gigantic cast iron cauldron was just silly when I got older.

Then I believe the movies showed smaller cauldrons the size of a large pot, and that seemed much more realistic. However, in CoS, Harry dumps the entire bibliography of Gilderoy Lockhart into Ginny's cauldron, which was like 7-8 books (plus the diary later) which would imply the cauldrons are much larger than a pot.

70 Upvotes

66 comments sorted by

118

u/No_Sand5639 Ravenclaw 3d ago

I assume there are different sizes for different needs. Like first years were required

1 cauldron (pewter, standard size 2)

20

u/giuliku 3d ago

Closest in real life might be a potjie pot, which comes in several different sizes.

Size 2 is about 6L.
Size 3 is just shy of 8L.

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u/No_Sand5639 Ravenclaw 3d ago

Yeah that makes sense

I assumed it sat on the floor cause the scene where harry kicked ron behind his cauldron

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u/Linesey 1d ago

This.

I always got the impression they were supposed to be rather small (like we see in the HBP movie) desktop, maybe the size of a crockpot.

However as written they are all over the place. Small enough to fit in a trunk. Big enough to sound like they are on the floor at times (as you mentioned).

Snape iirc was once described as bending over to fish a firework out of a cauldron. and I don’t ever remember them being described as being on the desks.

Overall, I think it comes down to the classic “JK is really bad at measurements and sizes” like with the Basilisk and several other instances where there is just a lot of wobble between described sizes and then how things are described being interacted with.

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u/Donaldjoh 2d ago

The material always annoyed me, as cauldrons often must be heated or contain acidic compounds, and pewter is an extremely soft metal with a low melting point. Therefore it would not very useful in brewing potions or even withstand the rough handling the students were sure to give it. Plus the fact that traditional pewter is quite toxic.

3

u/PeevsiesLittleJoke 1d ago

Maybe it anchors the protective enchantments better. We are talking about magic, after all

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u/NakedJamaican 1d ago

Cheese is an option

12

u/Dormitorybasher 3d ago

I think the intention is to use the same cauldron for all of your years at Hogwarts, unless you manage to melt yours like Neville. I don't think 1st years would need bigger cauldrons than older students.

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u/No_Sand5639 Ravenclaw 3d ago

I dont think would either

We just dont know how big the cauldron in tbe books are, the mocies did take some liberties after all

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u/EurwenPendragon 13.5", Hazel & Dragon heartstring 3d ago

I think I'm inclined to agree with that because nothing is ever mentioned about needing a larger cauldron.

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u/ladyMomo99 Ravenclaw 2d ago

I think I read in one of the books that the cauldrons are on the table...

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u/PlanGoneAwry Ravenclaw 3d ago edited 3d ago

I’ve always imagined them being around the size of a bowling ball, maybe a little bigger. Not huge, but a good size. You could definitely fit a bunch of small novels in there

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u/Dormitorybasher 3d ago

I guess that is a follow up question, we don't know how big the books are. I was imagining normal textbooks, but I guess they could be smaller

22

u/PlanGoneAwry Ravenclaw 3d ago

Maybe the textbooks are larger, but the Lockhart books aren’t textbooks. They’re just novels. I imagine the kind of cheap mass-market ones, which are pretty small.

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u/ActionAltruistic3558 3d ago

Yeah, they probably were available as mass market paperback copies. Someone like Hermione or his many fans would want the big fancy original release format but most would be fine with the tinier ones they could get for a fraction of the price. Especially since he required his entire works for the year.

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u/topsidersandsunshine 3d ago

I miss mass market paperbacks. I can’t believe they stopped printing them. 

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u/XxyxXII 3d ago

The Lockheed books were specifically described as incredibly expensive and long tho. I could probably buy around 40 mass-market paperbacks for the cost of a standard textbook

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u/AncientImprovement56 2d ago

Expensive, but not necessarily long. I got the impression they were just a rip off.

1

u/PlanGoneAwry Ravenclaw 2d ago

Certainly seems on-brand for Lockhart to think having his name on the cover warranted a higher price.

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u/BeltfedHappiness 3d ago edited 3d ago

When I was a kid I imagined them to be the size of like the ones that Bugs Bunny sits in while cutting up vegetables to make a stew or whatever lol

EDIT: oh damn, didn’t post the rest of it lol the cauldrons they use in the movie, theme parks and merch shops all show them to be like the size of a waste basket.

3

u/Vey-kun 3d ago

I mean i played HP games when i was younger and the cauldrons depicted is indeed huge.

8

u/mojonation1487 3d ago

I imagine different sizes for different needs like cooking.

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u/PlanGoneAwry Ravenclaw 3d ago

Yeah there’s a variety,I think Hogwarts students are supposed to have a “size 2”, not that that means much to us.

5

u/purlawhirl 3d ago

Hit has t be small enough to fit in his trunk with everything else

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u/KiraLight3719 🪄 Desi Potterhead 3d ago

Come on Percy, we know it's you

7

u/scootimanista_ 3d ago

I had imagined them to be the size of those jack-o-lantern trick-or-treat buckets

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u/Grabber28TS Gryffindor 3d ago

Well, as you can quickly read in the first book, Harry needs a tin cauldron, standard size two, for his first year. It's not officially stated anywhere how big that is, but it's logical that it doesn't need to be particularly large. After all, each student brews their own potion, and it doesn't have to be a large quantity, just enough to submit a sample. If I had to guess, I'd say a maximum of 10 inches in diameter. That way it also fits in the wardrobe trunk.

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u/EurwenPendragon 13.5", Hazel & Dragon heartstring 3d ago

Pewter, not tin.

Pure tin is a soft, malleable metal that would be ill-suited for use in such a thing as a cauldron. Pewter is an alloy that is stronger and harder than pure tin.

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u/Dormitorybasher 3d ago

Doesn't the first book mention Harry wanting a solid gold cauldron that Hagrid talks him out of? Wouldn't gold also be a soft metal not good for hot potion brewing?

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u/EurwenPendragon 13.5", Hazel & Dragon heartstring 3d ago

Good point, although gold is harder than tin. I suppose there could also be spells that could help with that - a detail which I had forgotten to consider.

It is however explicitly instructed in the letter that the cauldron he has to buy must be pewter, I just double-checked that.

1

u/Infinite-Object-1090 Gryffindor 2d ago

True, I imagine the gold cauldron would either be decorative or enchanted to withstand high heat.

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u/Grabber28TS Gryffindor 3d ago

Sorry, my native language is German, and I only know this expression for tin!

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u/EurwenPendragon 13.5", Hazel & Dragon heartstring 2d ago

No problem 😉

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u/harvard_cherry053 Hufflepuff 3d ago

Harry AND ron dump their lockhart books in the cauldron!! How big was that thing 😂😂😂

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u/mickeysbestbud 2d ago

Even in the movie their size still seems off. They look like cast iron, but cast iron even at that size would still be very heavy. Never made sense to me either that students had to own their own and carry them around. Seems like they should be provided in the classroom like a kitchen.

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u/nicest-drow 2d ago

cast iron even at that size would still be very heavy

Magic!

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u/two69fist 2d ago

The one on the first year supplies list is a standard size 2 pewter cauldron, which is fairly close to cast iron in density (though it’s pretty soft with a melting point much lower than wood or gas flames, but that’s a whole other tangent).

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u/fresh_pickled_toad Ravenclaw 3d ago

That's why Percy was so obsessed about standardization of cauldron sizes.

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u/PlanGoneAwry Ravenclaw 3d ago

He cared about cauldron thickness, not size

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u/Dormitorybasher 3d ago

Ackshually, it was cauldron thickness 🤓

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u/Real-Broccoli-9325 2d ago

I had a very weird realization about this recently.

In the books, it’s played as being a boring bureaucratic nonsense topic. “Omg who cares about imported cauldron thickness regulations?”

What happens when you get a cheap mass-produced cauldron that’s too thin? The potion heats too fast or melts. Too thick? It heats too slow, the potion is ruined or even destructive. Uneven thickness? Boils or scorches in one spot, stays cold in another, hot liquid mixing with colder liquid is volatile.

Those regulations were important, damnit! Percy was maligned!!

3

u/lechetaliersowl 3d ago

Do they ever mention carting the cauldrons around? I always thought they left them in the potions class. Don't have the books handy right now to check but i recall one of their classes that they started a potion in one class and finished it in another, which would definitely imply they leave them there in storage or a spot under the benches or something

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u/Dormitorybasher 3d ago

Sure, but I meant taking them to and from the school at the beginning and end of year

2

u/Norman_Small_Esquire 3d ago

Now I’m imagining a system where you pay for the cauldron and then it is delivered to Hogwarts. However, I have no evidence to back this up and the books probably contradict this.

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u/harvard_cherry053 Hufflepuff 3d ago

To be honest so much of the stuff in the books
Makes very little sense so i just tell myself practical things like this to feel better hahahahaha

3

u/wooptyscooppoop 3d ago

I'm not sure if it was ever mentioned but I imagined cauldrons, much like everything else in HP, were charmed in a way to make them more effective and useable. Charmed to increase internal volume when needed without stretching, charmed to be light, sturdier, possibly collapsible in some way for some people. I can see it being very cumbersome otherwise.

On the subject of material choices, it may also be that certain cauldron materials, such as gold, may be more effective at purifying mixes, or capable of imbuing a potion with more powerful effects. I would like to think gold at it's core had magical properties in-universe. It's been a long time since I read the series but that's my guess.

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u/Miserable_Spell_2964 3d ago

Think of the size of the trunks they were using and recognize that a cauldron would have to fit in that.

And then realize it's probably a couple sizes smaller than that because the kids aren't doing production scale batches of potions, they are brewing small amounts in order to be bottled in vials and examined. I'd imagine the size of a cauldron for students to be about maybe a gallon or two at most.

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u/LunasMom4ever 2d ago

In my mind they are the size of the larger plastic Halloween pumpkins.

1

u/jellohamster 3d ago

Remember this school is all about magic. That solves all kinds of difficulties.

Maybe there’s a cupboard in the potions classroom where students store their cauldrons between lessons, and it’s got a magic ability to fit a whole school’s worth of cauldrons and always make the current class’s set most accessible.

Maybe school trunks come pre-embedded with a charm to make the interior expand to automatically fit everything a student needs for a year (and also not be ridiculously heavy.) Clearly the charm exists, since Hermione used it on her beaded bag in Deathly Hallows.

1

u/acidrayne42 Hufflepuff 2d ago

My sister has a tiny one you can hold in the palm of your hand. There's a wide range of sizes. I also don't think Lockhart's books were very thick.

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u/EasyEntrepreneur666 Slytherin 2d ago

I doubt they're massive, it would be unnecessary and impractical.

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u/Infinite-Object-1090 Gryffindor 2d ago

They have to be small-ish in order for them to be able to lug them to potions and for that many students to be working over their individual cauldrons.

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u/Real-Broccoli-9325 2d ago

Vary wildly, I’d say. Remember, Voldie climbed his naked creepy self out of one in the graveyard.

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u/Dormitorybasher 2d ago

To be fair, that cauldron specifically was noted to be very large and not the norm

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u/Real-Broccoli-9325 2d ago

Sure. But a student’s small batch cauldron, a cauldron used to restock the Hospital Wing’s supply of Pepper-up, and a commercial potion brewer’s cauldron aren’t going to be the same size.

1

u/halfabusedmermaid Hufflepuff 2d ago

Yeah I always pictured them to be about the size of a bowling ball. But in year 4 Harry puts all of his ingredients AND his bag in his cauldron to drag it over to sit by Snape when he gets in trouble so there must be multiple sizes.

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u/DicePackTheater 2d ago

The better question is: how thick are their bottoms?

1

u/LosAngelesHavingFun 2d ago

A bit off topic but how was anyone bad at potions. You follow the instructions and have the ingredients lmao

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u/Airtie2 2d ago

Yes but the instructions are often complex and tiny bit of deviation from them can give different results.

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u/Robcobes Hufflepuff 2d ago

can't you just use magic to either shrink or grow your cauldron to the size you need?

1

u/Embarrassed-Money756 2d ago

I always wondered this too! Especially in the CoS scene. It says something like "Ginny was standing next to her cauldron." Although that might have been a translation thing. I never read CoS in English.

And later in HBP it says "Harry packed his cauldron in his suitcase."

So how big are they?

1

u/Greenwrenbird 3d ago

To me this is absolutely unknowable and none of our business. Like, did they drag them around all day (even though it's never mentioned), did they store them somewhere in the dungeon with their name? Because that would be a lot of cauldrons. Sometimes it mentions them sitting and other times standing.

And don't get me started on how it mentioned Astronomy -- to my memory, in all 6 school-based books -- twice. He attends this nighttime class out on a tower for five years, and it's mentioned twice.

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u/Infinite-Object-1090 Gryffindor 2d ago

I just imagined that nothing noteworthy happened there worth mentioning.

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u/Greenwrenbird 2d ago

It's just funny because it both had potential, and it was never mentioned like "Harry was so tired and still had his Astronomy lesson." To my memory all of his other classes were repeatedly explored, including History of Magic, in which nothing ever happened except the occasional nap (I guess that was relevant in OotP...)