Actual item name (Level)
Small Pot (Level 1)
Big Pot (Level 2)
Brewing Kettle (Level 3)
Cauldron (Level 4)
Improved Cauldron (Level 5 – Regeneration time is 1 minute or 2 coins)
Majestic Cauldron (Level 6 – Regeneration time is 5 minutes or 10 coins)
Mythical Cauldron (Level 7 – Regeneration time is 20 minutes or 24 coins; generates 40 items)
Legendary Cauldron (Level 8 – Regeneration time is 30 minutes or 40 coins; generates 42 items)

Just be aware that when you “upgrade” to the Majestic Cauldron, the number of items it generates drops down significantly from what you’d get with the Improved Cauldron. You get exactly 8 paper cups and enough of the pouch, pestle & mortar, and (a) cask(s) to create a Vial and a Small Potion.

This might not be a bad thing, because once you’re at that level, customers aren’t asking for that many items that are tied to the cauldrons. SUGGESTION: Just create the vials and sell ’em for purple gems, unless you get that rare customer asking for a cauldron-generated item.

The number in parenthesis represents the number of purple gems, if you decide to sell that item.
2x Pouch = Pestle & Mortar
2x Pestle & Mortar = Cask
2x Cask = Jug
2x Jug = Small Potion (1 gem)
2x Small Potion = Vial (2 gems)
2x Vial = Double Vials (3 gems)
2x Double Vials = Potion (4 gems)
2x Potion = Elixir (5 gems)
2x Elixir = Big Potion (6 gems)
2x Big Potion = Flask (7 gems)
2x Flask = Small Bottle (8 gems)
2x Small Bottle = Big Elixir (9 gems)
2x Big Elixir = Big Bottle (10 gems)
2x Big Bottle = Mega Potion (max level; 11 Gems)

BONUS ITEMS: (The number in parenthesis represents the number of purple gems, if you decide to sell that item.)
2x Paper Cup = Wooden Cup
2x Wooden Cup = Brass Cup (1 gem)
2x Brass Cup = Magic Cup (2 gems)
2x Magic Cup = Cursed Cup (max level; 3 gems)