Used to brew potions
A cauldron is a vessel similar to a bucket or kettle and is used to brew and hold potions and also may be used to carry supplies. Cauldrons are heated over an open fire and can be hung over a fire from an iron handle.
Many cauldrons have magical properties. The self-stirring cauldron was invented by Gaspard Shingleton. Bruno Schmidt of Germany once killed an Erkling by striking it with his father's collapsible cauldron. Shops in Diagon Alley sell both self-stirring and collapsible cauldrons. Other cauldrons may have Undetectable Extension Charms placed on them, as students often use them to carry many books and school supplies.
Types of cauldron
Here is a list of known types of cauldrons:
- Self-Stirring Cauldron
- Collapsible Cauldron
- Copper Cauldron - can be purchased at the price of 25 Galleons at Potage's Cauldron Shop.
- Brass Cauldron - costs 21 Galleons.
- Pewter Cauldron - can be purchased for 15 Galleons on Diagon Alley.
- Silver Cauldron
- Solid Gold Cauldron
In general, cauldrons must stand up to great wear and usage. As one of his first assignments with the Ministry of Magic, Percy Weasley worked with the Department of International Magical Cooperation lobbying for a standard for cauldron thickness. Apparently, there was an issue with sub-standard imported cauldrons having defective, thin bottoms. Perhaps this is the cause for Neville Longbottom's knack for melting cauldrons during Potions class. First years at Hogwarts School of Witchcraft and Wizardry used pewter standard size 2 cauldrons, as mentioned on the list that accompanied their Hogwarts acceptance letter.
Revolutions in cauldron making
There are always new attempts to revolutionise the cauldron. Humphrey Belcher theorised "the time was ripe for a cheese cauldron." The fire crab, which resembles a tortoise with a jewelled shell that shoots fire out its back end, is prized for its shell for use as a cauldron. This practise of poaching has lead to protected colonies in its native habitat of Fiji island.
Cauldrons in culture
- The Leaky Cauldron of London is a popular pub for Wizards.
- Cauldron Cakes are treats beloved by wizarding children.
- Singer Celestina Warbeck sings tunes called "You Stole My Cauldron but You Can't Have my Heart," and "A Cauldron Full of Hot, Strong Love."
- Chocolate Cauldrons are boxed chocolates (eight to a box), shaped like cauldrons and filled with firewhiskey.
Behind the scenes
- In the film version of Harry Potter and the Prisoner of Azkaban, the song Something Wicked This Way Comes was performed by the Hogwarts Student Choir at the Sorting Feast. The lyrics are taken from the opening scene of William Shakespeare's Macbeth. It was by John Williams.
- Pottermore allows users to brew potions. When making them, ingredients are added to the cauldron, sometimes after being crushed with the pestle and mortar. The cauldron must be kept at the right temperature using the buttons below the cauldron on the brewing page; if the temperature is too high, the cauldron will melt and the potion maker will lose five points. When a cauldron melts, it cannot be reused and the potion maker must replace it with a new one from Potage's Cauldron Shop. 
- Users of Pottermore are allowed to own only one of every available type of cauldron at Potage's Cauldron Shop - Pewter Cauldron, Copper Cauldron, Brass Cauldron.
- Harry Potter and the Philosopher's Stone (First appearance)
- Harry Potter and the Chamber of Secrets
- Harry Potter and the Prisoner of Azkaban
- Harry Potter and the Goblet of Fire
- Harry Potter and the Order of the Phoenix
- Harry Potter and the Order of the Phoenix (film)
- Harry Potter and the Half-Blood Prince
- Harry Potter and the Half-Blood Prince (film)
- Harry Potter and the Deathly Hallows
- LEGO Harry Potter: Characters of the Magical World
- LEGO Harry Potter: Years 1-4
- LEGO Harry Potter: Years 5-7