You may have a lot of Super Brie but Stale SuperBrie cannot be bought or crafted. Stale SuperBrie is an essential item used for crafting the RhinoBot Trap.
The easiest way to collect Stale SUPER|Brie+ is to head to either the Forbidden Grove or the Acolyte Realm and use SUPER|Brie+ with a trap setup that has an Extremely Stale cheese effect or worse. I have used the Arcane Capturing Rod Of Never Yielding Mystery with Magma Base to get Stale SuperBrie. Every time my SuperBrie cheese turn stale, I will get the Stale SuperBrie.
Stale SUPER|brie+ can also be created without using SUPER|brie+ by crafting Runic without using Magic Essence, traveling outside Bristle Woods, and using a trap with an Extremely Stale or worse cheese effect. Stale SUPER|brie+ is also dropped by Aged mice in Cape Clawed.
